diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/Kconfig | 1 | ||||
| -rw-r--r-- | security/Makefile | 2 | ||||
| -rw-r--r-- | security/commoncap.c | 134 | ||||
| -rw-r--r-- | security/dummy.c | 19 | ||||
| -rw-r--r-- | security/security.c | 4 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 43 | ||||
| -rw-r--r-- | security/smack/Kconfig | 10 | ||||
| -rw-r--r-- | security/smack/Makefile | 7 | ||||
| -rw-r--r-- | security/smack/smack.h | 220 | ||||
| -rw-r--r-- | security/smack/smack_access.c | 356 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 2518 | ||||
| -rw-r--r-- | security/smack/smackfs.c | 981 |
12 files changed, 4206 insertions, 89 deletions
diff --git a/security/Kconfig b/security/Kconfig index 389e151e3b68..25ffe1b9dc98 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -105,6 +105,7 @@ config SECURITY_ROOTPLUG If you are unsure how to answer this question, answer N. source security/selinux/Kconfig +source security/smack/Kconfig endmenu diff --git a/security/Makefile b/security/Makefile index ef87df2f50a4..9e8b02525014 100644 --- a/security/Makefile +++ b/security/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_KEYS) += keys/ subdir-$(CONFIG_SECURITY_SELINUX) += selinux +subdir-$(CONFIG_SECURITY_SMACK) += smack # if we don't select a security model, use the default capabilities ifneq ($(CONFIG_SECURITY),y) @@ -14,5 +15,6 @@ endif obj-$(CONFIG_SECURITY) += security.o dummy.o inode.o # Must precede capability.o in order to stack properly. obj-$(CONFIG_SECURITY_SELINUX) += selinux/built-in.o +obj-$(CONFIG_SECURITY_SMACK) += commoncap.o smack/built-in.o obj-$(CONFIG_SECURITY_CAPABILITIES) += commoncap.o capability.o obj-$(CONFIG_SECURITY_ROOTPLUG) += commoncap.o root_plug.o diff --git a/security/commoncap.c b/security/commoncap.c index ea61bc73f6d3..5aba82679a0b 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -1,4 +1,4 @@ -/* Common capabilities, needed by capability.o and root_plug.o +/* Common capabilities, needed by capability.o and root_plug.o * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -25,20 +25,6 @@ #include <linux/mount.h> #include <linux/sched.h> -#ifdef CONFIG_SECURITY_FILE_CAPABILITIES -/* - * Because of the reduced scope of CAP_SETPCAP when filesystem - * capabilities are in effect, it is safe to allow this capability to - * be available in the default configuration. - */ -# define CAP_INIT_BSET CAP_FULL_SET -#else /* ie. ndef CONFIG_SECURITY_FILE_CAPABILITIES */ -# define CAP_INIT_BSET CAP_INIT_EFF_SET -#endif /* def CONFIG_SECURITY_FILE_CAPABILITIES */ - -kernel_cap_t cap_bset = CAP_INIT_BSET; /* systemwide capability bound */ -EXPORT_SYMBOL(cap_bset); - /* Global security state */ unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */ @@ -93,9 +79,9 @@ int cap_capget (struct task_struct *target, kernel_cap_t *effective, kernel_cap_t *inheritable, kernel_cap_t *permitted) { /* Derived from kernel/capability.c:sys_capget. */ - *effective = cap_t (target->cap_effective); - *inheritable = cap_t (target->cap_inheritable); - *permitted = cap_t (target->cap_permitted); + *effective = target->cap_effective; + *inheritable = target->cap_inheritable; + *permitted = target->cap_permitted; return 0; } @@ -140,6 +126,12 @@ int cap_capset_check (struct task_struct *target, kernel_cap_t *effective, /* incapable of using this inheritable set */ return -EPERM; } + if (!cap_issubset(*inheritable, + cap_combine(target->cap_inheritable, + current->cap_bset))) { + /* no new pI capabilities outside bounding set */ + return -EPERM; + } /* verify restrictions on target's new Permitted set */ if (!cap_issubset (*permitted, @@ -198,28 +190,50 @@ int cap_inode_killpriv(struct dentry *dentry) } static inline int cap_from_disk(struct vfs_cap_data *caps, - struct linux_binprm *bprm, - int size) + struct linux_binprm *bprm, unsigned size) { __u32 magic_etc; + unsigned tocopy, i; - if (size != XATTR_CAPS_SZ) + if (size < sizeof(magic_etc)) return -EINVAL; magic_etc = le32_to_cpu(caps->magic_etc); switch ((magic_etc & VFS_CAP_REVISION_MASK)) { - case VFS_CAP_REVISION: - if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) - bprm->cap_effective = true; - else - bprm->cap_effective = false; - bprm->cap_permitted = to_cap_t(le32_to_cpu(caps->permitted)); - bprm->cap_inheritable = to_cap_t(le32_to_cpu(caps->inheritable)); - return 0; + case VFS_CAP_REVISION_1: + if (size != XATTR_CAPS_SZ_1) + return -EINVAL; + tocopy = VFS_CAP_U32_1; + break; + case VFS_CAP_REVISION_2: + if (size != XATTR_CAPS_SZ_2) + return -EINVAL; + tocopy = VFS_CAP_U32_2; + break; default: return -EINVAL; } + + if (magic_etc & VFS_CAP_FLAGS_EFFECTIVE) { + bprm->cap_effective = true; + } else { + bprm->cap_effective = false; + } + + for (i = 0; i < tocopy; ++i) { + bprm->cap_permitted.cap[i] = + le32_to_cpu(caps->data[i].permitted); + bprm->cap_inheritable.cap[i] = + le32_to_cpu(caps->data[i].inheritable); + } + while (i < VFS_CAP_U32) { + bprm->cap_permitted.cap[i] = 0; + bprm->cap_inheritable.cap[i] = 0; + i++; + } + + return 0; } /* Locate any VFS capabilities: */ @@ -227,7 +241,7 @@ static int get_file_caps(struct linux_binprm *bprm) { struct dentry *dentry; int rc = 0; - struct vfs_cap_data incaps; + struct vfs_cap_data vcaps; struct inode *inode; if (bprm->file->f_vfsmnt->mnt_flags & MNT_NOSUID) { @@ -240,14 +254,8 @@ static int get_file_caps(struct linux_binprm *bprm) if (!inode->i_op || !inode->i_op->getxattr) goto out; - rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, NULL, 0); - if (rc > 0) { - if (rc == XATTR_CAPS_SZ) - rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, - &incaps, XATTR_CAPS_SZ); - else - rc = -EINVAL; - } + rc = inode->i_op->getxattr(dentry, XATTR_NAME_CAPS, &vcaps, + XATTR_CAPS_SZ); if (rc == -ENODATA || rc == -EOPNOTSUPP) { /* no data, that's ok */ rc = 0; @@ -256,7 +264,7 @@ static int get_file_caps(struct linux_binprm *bprm) if (rc < 0) goto out; - rc = cap_from_disk(&incaps, bprm, rc); + rc = cap_from_disk(&vcaps, bprm, rc); if (rc) printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", __FUNCTION__, rc, bprm->filename); @@ -321,10 +329,11 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) /* Derived from fs/exec.c:compute_creds. */ kernel_cap_t new_permitted, working; - new_permitted = cap_intersect (bprm->cap_permitted, cap_bset); - working = cap_intersect (bprm->cap_inheritable, + new_permitted = cap_intersect(bprm->cap_permitted, + current->cap_bset); + working = cap_intersect(bprm->cap_inheritable, current->cap_inheritable); - new_permitted = cap_combine (new_permitted, working); + new_permitted = cap_combine(new_permitted, working); if (bprm->e_uid != current->uid || bprm->e_gid != current->gid || !cap_issubset (new_permitted, current->cap_permitted)) { @@ -351,8 +360,10 @@ void cap_bprm_apply_creds (struct linux_binprm *bprm, int unsafe) * capability rules */ if (!is_global_init(current)) { current->cap_permitted = new_permitted; - current->cap_effective = bprm->cap_effective ? - new_permitted : 0; + if (bprm->cap_effective) + current->cap_effective = new_permitted; + else + cap_clear(current->cap_effective); } /* AUD: Audit candidate if current->cap_effective is set */ @@ -474,13 +485,15 @@ int cap_task_post_setuid (uid_t old_ruid, uid_t old_euid, uid_t old_suid, if (!issecure (SECURE_NO_SETUID_FIXUP)) { if (old_fsuid == 0 && current->fsuid != 0) { - cap_t (current->cap_effective) &= - ~CAP_FS_MASK; + current->cap_effective = + cap_drop_fs_set( + current->cap_effective); } if (old_fsuid != 0 && current->fsuid == 0) { - cap_t (current->cap_effective) |= - (cap_t (current->cap_permitted) & - CAP_FS_MASK); + current->cap_effective = + cap_raise_fs_set( + current->cap_effective, + current->cap_permitted); } } break; @@ -561,6 +574,23 @@ int cap_task_kill(struct task_struct *p, struct siginfo *info, return -EPERM; } + +/* + * called from kernel/sys.c for prctl(PR_CABSET_DROP) + * done without task_capability_lock() because it introduces + * no new races - i.e. only another task doing capget() on + * this task could get inconsistent info. There can be no + * racing writer bc a task can only change its own caps. + */ +long cap_prctl_drop(unsigned long cap) +{ + if (!capable(CAP_SETPCAP)) + return -EPERM; + if (!cap_valid(cap)) + return -EINVAL; + cap_lower(current->cap_bset, cap); + return 0; +} #else int cap_task_setscheduler (struct task_struct *p, int policy, struct sched_param *lp) @@ -584,9 +614,9 @@ int cap_task_kill(struct task_struct *p, struct siginfo *info, void cap_task_reparent_to_init (struct task_struct *p) { - p->cap_effective = CAP_INIT_EFF_SET; - p->cap_inheritable = CAP_INIT_INH_SET; - p->cap_permitted = CAP_FULL_SET; + cap_set_init_eff(p->cap_effective); + cap_clear(p->cap_inheritable); + cap_set_full(p->cap_permitted); p->keep_capabilities = 0; return; } diff --git a/security/dummy.c b/security/dummy.c index 48d4b0a52737..649326bf64ea 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -36,14 +36,19 @@ static int dummy_ptrace (struct task_struct *parent, struct task_struct *child) static int dummy_capget (struct task_struct *target, kernel_cap_t * effective, kernel_cap_t * inheritable, kernel_cap_t * permitted) { - *effective = *inheritable = *permitted = 0; if (target->euid == 0) { - *permitted |= (~0 & ~CAP_FS_MASK); - *effective |= (~0 & ~CAP_TO_MASK(CAP_SETPCAP) & ~CAP_FS_MASK); + cap_set_full(*permitted); + cap_set_init_eff(*effective); + } else { + cap_clear(*permitted); + cap_clear(*effective); } - if (target->fsuid == 0) { - *permitted |= CAP_FS_MASK; - *effective |= CAP_FS_MASK; + + cap_clear(*inheritable); + + if (target->fsuid != 0) { + *permitted = cap_drop_fs_set(*permitted); + *effective = cap_drop_fs_set(*effective); } return 0; } @@ -402,7 +407,7 @@ static int dummy_inode_killpriv(struct dentry *dentry) return 0; } -static int dummy_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err) +static int dummy_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) { return -EOPNOTSUPP; } diff --git a/security/security.c b/security/security.c index ca475ca206e4..b6c57a6b2ff5 100644 --- a/security/security.c +++ b/security/security.c @@ -493,11 +493,11 @@ int security_inode_killpriv(struct dentry *dentry) return security_ops->inode_killpriv(dentry); } -int security_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err) +int security_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) { if (unlikely(IS_PRIVATE(inode))) return 0; - return security_ops->inode_getsecurity(inode, name, buffer, size, err); + return security_ops->inode_getsecurity(inode, name, buffer, alloc); } int security_inode_setsecurity(struct inode *inode, const char *name, const void *value, size_t size, int flags) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index be6de0b8734f..e5ed07510309 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -136,32 +136,6 @@ static DEFINE_SPINLOCK(sb_security_lock); static struct kmem_cache *sel_inode_cache; -/* Return security context for a given sid or just the context - length if the buffer is null or length is 0 */ -static int selinux_getsecurity(u32 sid, void *buffer, size_t size) -{ - char *context; - unsigned len; - int rc; - - rc = security_sid_to_context(sid, &context, &len); - if (rc) - return rc; - - if (!buffer || !size) - goto getsecurity_exit; - - if (size < len) { - len = -ERANGE; - goto getsecurity_exit; - } - memcpy(buffer, context, len); - -getsecurity_exit: - kfree(context); - return len; -} - /** * selinux_secmark_enabled - Check to see if SECMARK is currently enabled * @@ -2675,14 +2649,27 @@ static int selinux_inode_removexattr (struct dentry *dentry, char *name) * * Permission check is handled by selinux_inode_getxattr hook. */ -static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void *buffer, size_t size, int err) +static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) { + u32 size; + int error; + char *context = NULL; struct inode_security_struct *isec = inode->i_security; if (strcmp(name, XATTR_SELINUX_SUFFIX)) return -EOPNOTSUPP; - return selinux_getsecurity(isec->sid, buffer, size); + error = security_sid_to_context(isec->sid, &context, &size); + if (error) + return error; + error = size; + if (alloc) { + *buffer = context; + goto out_nofree; + } + kfree(context); +out_nofree: + return error; } static int selinux_inode_setsecurity(struct inode *inode, const char *name, diff --git a/security/smack/Kconfig b/security/smack/Kconfig new file mode 100644 index 000000000000..603b08784341 --- /dev/null +++ b/security/smack/Kconfig @@ -0,0 +1,10 @@ +config SECURITY_SMACK + bool "Simplified Mandatory Access Control Kernel Support" + depends on NETLABEL && SECURITY_NETWORK + default n + help + This selects the Simplified Mandatory Access Control Kernel. + Smack is useful for sensitivity, integrity, and a variety + of other mandatory security schemes. + If you are unsure how to answer this question, answer N. + diff --git a/security/smack/Makefile b/security/smack/Makefile new file mode 100644 index 000000000000..67a63aaec827 --- /dev/null +++ b/security/smack/Makefile @@ -0,0 +1,7 @@ +# +# Makefile for the SMACK LSM +# + +obj-$(CONFIG_SECURITY_SMACK) := smack.o + +smack-y := smack_lsm.o smack_access.o smackfs.o diff --git a/security/smack/smack.h b/security/smack/smack.h new file mode 100644 index 000000000000..a21a0e907ab3 --- /dev/null +++ b/security/smack/smack.h @@ -0,0 +1,220 @@ +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2. + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + */ + +#ifndef _SECURITY_SMACK_H +#define _SECURITY_SMACK_H + +#include <linux/capability.h> +#include <linux/spinlock.h> +#include <net/netlabel.h> + +/* + * Why 23? CIPSO is constrained to 30, so a 32 byte buffer is + * bigger than can be used, and 24 is the next lower multiple + * of 8, and there are too many issues if there isn't space set + * aside for the terminating null byte. + */ +#define SMK_MAXLEN 23 +#define SMK_LABELLEN (SMK_MAXLEN+1) + +/* + * How many kinds of access are there? + * Here's your answer. + */ +#define SMK_ACCESSDASH '-' +#define SMK_ACCESSLOW "rwxa" +#define SMK_ACCESSKINDS (sizeof(SMK_ACCESSLOW) - 1) + +struct superblock_smack { + char *smk_root; + char *smk_floor; + char *smk_hat; + char *smk_default; + int smk_initialized; + spinlock_t smk_sblock; /* for initialization */ +}; + +struct socket_smack { + char *smk_out; /* outbound label */ + char *smk_in; /* inbound label */ + char smk_packet[SMK_LABELLEN]; /* TCP peer label */ +}; + +/* + * Inode smack data + */ +struct inode_smack { + char *smk_inode; /* label of the fso */ + struct mutex smk_lock; /* initialization lock */ + int smk_flags; /* smack inode flags */ +}; + +#define SMK_INODE_INSTANT 0x01 /* inode is instantiated */ + +/* + * A label access rule. + */ +struct smack_rule { + char *smk_subject; + char *smk_object; + int smk_access; +}; + +/* + * An entry in the table of permitted label accesses. + */ +struct smk_list_entry { + struct smk_list_entry *smk_next; + struct smack_rule smk_rule; +}; + +/* + * An entry in the table mapping smack values to + * CIPSO level/category-set values. + */ +struct smack_cipso { + int smk_level; + char smk_catset[SMK_LABELLEN]; +}; + +/* + * This is the repository for labels seen so that it is + * not necessary to keep allocating tiny chuncks of memory + * and so that they can be shared. + * + * Labels are never modified in place. Anytime a label + * is imported (e.g. xattrset on a file) the list is checked + * for it and it is added if it doesn't exist. The address + * is passed out in either case. Entries are added, but + * never deleted. + * + * Since labels are hanging around anyway it doesn't + * hurt to maintain a secid for those awkward situations + * where kernel components that ought to use LSM independent + * interfaces don't. The secid should go away when all of + * these components have been repaired. + * + * If there is a cipso value associated with the label it + * gets stored here, too. This will most likely be rare as + * the cipso direct mapping in used internally. + */ +struct smack_known { + struct smack_known *smk_next; + char smk_known[SMK_LABELLEN]; + u32 smk_secid; + struct smack_cipso *smk_cipso; + spinlock_t smk_cipsolock; /* for changing cipso map */ +}; + +/* + * Mount options + */ +#define SMK_FSDEFAULT "smackfsdef=" +#define SMK_FSFLOOR "smackfsfloor=" +#define SMK_FSHAT "smackfshat=" +#define SMK_FSROOT "smackfsroot=" + +/* + * xattr names + */ +#define XATTR_SMACK_SUFFIX "SMACK64" +#define XATTR_SMACK_IPIN "SMACK64IPIN" +#define XATTR_SMACK_IPOUT "SMACK64IPOUT" +#define XATTR_NAME_SMACK XATTR_SECURITY_PREFIX XATTR_SMACK_SUFFIX +#define XATTR_NAME_SMACKIPIN XATTR_SECURITY_PREFIX XATTR_SMACK_IPIN +#define XATTR_NAME_SMACKIPOUT XATTR_SECURITY_PREFIX XATTR_SMACK_IPOUT + +/* + * smackfs macic number + */ +#define SMACK_MAGIC 0x43415d53 /* "SMAC" */ + +/* + * A limit on the number of entries in the lists + * makes some of the list administration easier. + */ +#define SMACK_LIST_MAX 10000 + +/* + * CIPSO defaults. + */ +#define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */ +#define SMACK_CIPSO_DIRECT_DEFAULT 250 /* Arbitrary */ +#define SMACK_CIPSO_MAXCATVAL 63 /* Bigger gets harder */ +#define SMACK_CIPSO_MAXLEVEL 255 /* CIPSO 2.2 standard */ +#define SMACK_CIPSO_MAXCATNUM 239 /* CIPSO 2.2 standard */ + +/* + * Just to make the common cases easier to deal with + */ +#define MAY_ANY (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC) +#define MAY_ANYREAD (MAY_READ | MAY_EXEC) +#define MAY_ANYWRITE (MAY_WRITE | MAY_APPEND) +#define MAY_READWRITE (MAY_READ | MAY_WRITE) +#define MAY_NOT 0 + +/* + * These functions are in smack_lsm.c + */ +struct inode_smack *new_inode_smack(char *); + +/* + * These functions are in smack_access.c + */ +int smk_access(char *, char *, int); +int smk_curacc(char *, u32); +int smack_to_cipso(const char *, struct smack_cipso *); +void smack_from_cipso(u32, char *, char *); +char *smack_from_secid(const u32); +char *smk_import(const char *, int); +struct smack_known *smk_import_entry(const char *, int); +u32 smack_to_secid(const char *); + +/* + * Shared data. + */ +extern int smack_cipso_direct; +extern int smack_net_nltype; +extern char *smack_net_ambient; + +extern struct smack_known *smack_known; +extern struct smack_known smack_known_floor; +extern struct smack_known smack_known_hat; +extern struct smack_known smack_known_huh; +extern struct smack_known smack_known_invalid; +extern struct smack_known smack_known_star; +extern struct smack_known smack_known_unset; + +extern struct smk_list_entry *smack_list; + +/* + * Stricly for CIPSO level manipulation. + * Set the category bit number in a smack label sized buffer. + */ +static inline void smack_catset_bit(int cat, char *catsetp) +{ + if (cat > SMK_LABELLEN * 8) + return; + + catsetp[(cat - 1) / 8] |= 0x80 >> ((cat - 1) % 8); +} + +/* + * Present a pointer to the smack label in an inode blob. + */ +static inline char *smk_of_inode(const struct inode *isp) +{ + struct inode_smack *sip = isp->i_security; + return sip->smk_inode; +} + +#endif /* _SECURITY_SMACK_H */ diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c new file mode 100644 index 000000000000..f6b5f6eed6dd --- /dev/null +++ b/security/smack/smack_access.c @@ -0,0 +1,356 @@ +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2. + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + */ + +#include <linux/types.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include "smack.h" + +struct smack_known smack_known_unset = { + .smk_next = NULL, + .smk_known = "UNSET", + .smk_secid = 1, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_huh = { + .smk_next = &smack_known_unset, + .smk_known = "?", + .smk_secid = 2, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_hat = { + .smk_next = &smack_known_huh, + .smk_known = "^", + .smk_secid = 3, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_star = { + .smk_next = &smack_known_hat, + .smk_known = "*", + .smk_secid = 4, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_floor = { + .smk_next = &smack_known_star, + .smk_known = "_", + .smk_secid = 5, + .smk_cipso = NULL, +}; + +struct smack_known smack_known_invalid = { + .smk_next = &smack_known_floor, + .smk_known = "", + .smk_secid = 6, + .smk_cipso = NULL, +}; + +struct smack_known *smack_known = &smack_known_invalid; + +/* + * The initial value needs to be bigger than any of the + * known values above. + */ +static u32 smack_next_secid = 10; + +/** + * smk_access - determine if a subject has a specific access to an object + * @subject_label: a pointer to the subject's Smack label + * @object_label: a pointer to the object's Smack label + * @request: the access requested, in "MAY" format + * + * This function looks up the subject/object pair in the + * access rule list and returns 0 if the access is permitted, + * non zero otherwise. + * + * Even though Smack labels are usually shared on smack_list + * labels that come in off the network can't be imported + * and added to the list for locking reasons. + * + * Therefore, it is necessary to check the contents of the labels, + * not just the pointer values. Of course, in most cases the labels + * will be on the list, so checking the pointers may be a worthwhile + * optimization. + */ +int smk_access(char *subject_label, char *object_label, int request) +{ + u32 may = MAY_NOT; + struct smk_list_entry *sp; + struct smack_rule *srp; + + /* + * Hardcoded comparisons. + * + * A star subject can't access any object. + */ + if (subject_label == smack_known_star.smk_known || + strcmp(subject_label, smack_known_star.smk_known) == 0) + return -EACCES; + /* + * A star object can be accessed by any subject. + */ + if (object_label == smack_known_star.smk_known || + strcmp(object_label, smack_known_star.smk_known) == 0) + return 0; + /* + * An object can be accessed in any way by a subject + * with the same label. + */ + if (subject_label == object_label || + strcmp(subject_label, object_label) == 0) + return 0; + /* + * A hat subject can read any object. + * A floor object can be read by any subject. + */ + if ((request & MAY_ANYREAD) == request) { + if (object_label == smack_known_floor.smk_known || + strcmp(object_label, smack_known_floor.smk_known) == 0) + return 0; + if (subject_label == smack_known_hat.smk_known || + strcmp(subject_label, smack_known_hat.smk_known) == 0) + return 0; + } + /* + * Beyond here an explicit relationship is required. + * If the requested access is contained in the available + * access (e.g. read is included in readwrite) it's + * good. + */ + for (sp = smack_list; sp != NULL; sp = sp->smk_next) { + srp = &sp->smk_rule; + + if (srp->smk_subject == subject_label || + strcmp(srp->smk_subject, subject_label) == 0) { + if (srp->smk_object == object_label || + strcmp(srp->smk_object, object_label) == 0) { + may = srp->smk_access; + break; + } + } + } + /* + * This is a bit map operation. + */ + if ((request & may) == request) + return 0; + + return -EACCES; +} + +/** + * smk_curacc - determine if current has a specific access to an object + * @object_label: a pointer to the object's Smack label + * @request: the access requested, in "MAY" format + * + * This function checks the current subject label/object label pair + * in the access rule list and returns 0 if the access is permitted, + * non zero otherwise. It allows that current my have the capability + * to override the rules. + */ +int smk_curacc(char *obj_label, u32 mode) +{ + int rc; + + rc = smk_access(current->security, obj_label, mode); + if (rc == 0) + return 0; + + if (capable(CAP_MAC_OVERRIDE)) + return 0; + + return rc; +} + +static DEFINE_MUTEX(smack_known_lock); + +/** + * smk_import_entry - import a label, return the list entry + * @string: a text string that might be a Smack label + * @len: the maximum size, or zero if it is NULL terminated. + * + * Returns a pointer to the entry in the label list that + * matches the passed string, adding it if necessary. + */ +struct smack_known *smk_import_entry(const char *string, int len) +{ + struct smack_known *skp; + char smack[SMK_LABELLEN]; + int found; + int i; + + if (len <= 0 || len > SMK_MAXLEN) + len = SMK_MAXLEN; + + for (i = 0, found = 0; i < SMK_LABELLEN; i++) { + if (found) + smack[i] = '\0'; + else if (i >= len || string[i] > '~' || string[i] <= ' ' || + string[i] == '/') { + smack[i] = '\0'; + found = 1; + } else + smack[i] = string[i]; + } + + if (smack[0] == '\0') + return NULL; + + mutex_lock(&smack_known_lock); + + for (skp = smack_known; skp != NULL; skp = skp->smk_next) + if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) + break; + + if (skp == NULL) { + skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL); + if (skp != NULL) { + skp->smk_next = smack_known; + strncpy(skp->smk_known, smack, SMK_MAXLEN); + skp->smk_secid = smack_next_secid++; + skp->smk_cipso = NULL; + spin_lock_init(&skp->smk_cipsolock); + /* + * Make sure that the entry is actually + * filled before putting it on the list. + */ + smp_mb(); + smack_known = skp; + } + } + + mutex_unlock(&smack_known_lock); + + return skp; +} + +/** + * smk_import - import a smack label + * @string: a text string that might be a Smack label + * @len: the maximum size, or zero if it is NULL terminated. + * + * Returns a pointer to the label in the label list that + * matches the passed string, adding it if necessary. + */ +char *smk_import(const char *string, int len) +{ + struct smack_known *skp; + + skp = smk_import_entry(string, len); + if (skp == NULL) + return NULL; + return skp->smk_known; +} + +/** + * smack_from_secid - find the Smack label associated with a secid + * @secid: an integer that might be associated with a Smack label + * + * Returns a pointer to the appropraite Smack label if there is one, + * otherwise a pointer to the invalid Smack label. + */ +char *smack_from_secid(const u32 secid) +{ + struct smack_known *skp; + + for (skp = smack_known; skp != NULL; skp = skp->smk_next) + if (skp->smk_secid == secid) + return skp->smk_known; + + /* + * If we got this far someone asked for the translation + * of a secid that is not on the list. + */ + return smack_known_invalid.smk_known; +} + +/** + * smack_to_secid - find the secid associated with a Smack label + * @smack: the Smack label + * + * Returns the appropriate secid if there is one, + * otherwise 0 + */ +u32 smack_to_secid(const char *smack) +{ + struct smack_known *skp; + + for (skp = smack_known; skp != NULL; skp = skp->smk_next) + if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) + return skp->smk_secid; + return 0; +} + +/** + * smack_from_cipso - find the Smack label associated with a CIPSO option + * @level: Bell & LaPadula level from the network + * @cp: Bell & LaPadula categories from the network + * @result: where to put the Smack value + * + * This is a simple lookup in the label table. + * + * This is an odd duck as far as smack handling goes in that + * it sends back a copy of the smack label rather than a pointer + * to the master list. This is done because it is possible for + * a foreign host to send a smack label that is new to this + * machine and hence not on the list. That would not be an + * issue except that adding an entry to the master list can't + * be done at that point. + */ +void smack_from_cipso(u32 level, char *cp, char *result) +{ + struct smack_known *kp; + char *final = NULL; + + for (kp = smack_known; final == NULL && kp != NULL; kp = kp->smk_next) { + if (kp->smk_cipso == NULL) + continue; + + spin_lock_bh(&kp->smk_cipsolock); + + if (kp->smk_cipso->smk_level == level && + memcmp(kp->smk_cipso->smk_catset, cp, SMK_LABELLEN) == 0) + final = kp->smk_known; + + spin_unlock_bh(&kp->smk_cipsolock); + } + if (final == NULL) + final = smack_known_huh.smk_known; + strncpy(result, final, SMK_MAXLEN); + return; +} + +/** + * smack_to_cipso - find the CIPSO option to go with a Smack label + * @smack: a pointer to the smack label in question + * @cp: where to put the result + * + * Returns zero if a value is available, non-zero otherwise. + */ +int smack_to_cipso(const char *smack, struct smack_cipso *cp) +{ + struct smack_known *kp; + + for (kp = smack_known; kp != NULL; kp = kp->smk_next) + if (kp->smk_known == smack || + strcmp(kp->smk_known, smack) == 0) + break; + + if (kp == NULL || kp->smk_cipso == NULL) + return -ENOENT; + + memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso)); + return 0; +} diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c new file mode 100644 index 000000000000..1c11e4245859 --- /dev/null +++ b/security/smack/smack_lsm.c @@ -0,0 +1,2518 @@ +/* + * Simplified MAC Kernel (smack) security module + * + * This file contains the smack hook function implementations. + * + * Author: + * Casey Schaufler <casey@schaufler-ca.com> + * + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2, + * as published by the Free Software Foundation. + */ + +#include <linux/xattr.h> +#include <linux/pagemap.h> +#include <linux/mount.h> +#include <linux/stat.h> +#include <linux/ext2_fs.h> +#include <linux/kd.h> +#include <asm/ioctls.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/mutex.h> +#include <linux/pipe_fs_i.h> +#include <net/netlabel.h> +#include <net/cipso_ipv4.h> + +#include "smack.h" + +/* + * I hope these are the hokeyist lines of code in the module. Casey. + */ +#define DEVPTS_SUPER_MAGIC 0x1cd1 +#define SOCKFS_MAGIC 0x534F434B +#define TMPFS_MAGIC 0x01021994 + +/** + * smk_fetch - Fetch the smack label from a file. + * @ip: a pointer to the inode + * @dp: a pointer to the dentry + * + * Returns a pointer to the master list entry for the Smack label + * or NULL if there was no label to fetch. + */ +static char *smk_fetch(struct inode *ip, struct dentry *dp) +{ + int rc; + char in[SMK_LABELLEN]; + + if (ip->i_op->getxattr == NULL) + return NULL; + + rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN); + if (rc < 0) + return NULL; + + return smk_import(in, rc); +} + +/** + * new_inode_smack - allocate an inode security blob + * @smack: a pointer to the Smack label to use in the blob + * + * Returns the new blob or NULL if there's no memory available + */ +struct inode_smack *new_inode_smack(char *smack) +{ + struct inode_smack *isp; + + isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL); + if (isp == NULL) + return NULL; + + isp->smk_inode = smack; + isp->smk_flags = 0; + mutex_init(&isp->smk_lock); + + return isp; +} + +/* + * LSM hooks. + * We he, that is fun! + */ + +/** + * smack_ptrace - Smack approval on ptrace + * @ptp: parent task pointer + * @ctp: child task pointer + * + * Returns 0 if access is OK, an error code otherwise + * + * Do the capability checks, and require read and write. + */ +static int smack_ptrace(struct task_struct *ptp, struct task_struct *ctp) +{ + int rc; + + rc = cap_ptrace(ptp, ctp); + if (rc != 0) + return rc; + + rc = smk_access(ptp->security, ctp->security, MAY_READWRITE); + if (rc != 0 && __capable(ptp, CAP_MAC_OVERRIDE)) + return 0; + + return rc; +} + +/** + * smack_syslog - Smack approval on syslog + * @type: message type + * + * Require that the task has the floor label + * + * Returns 0 on success, error code otherwise. + */ +static int smack_syslog(int type) +{ + int rc; + char *sp = current->security; + + rc = cap_syslog(type); + if (rc != 0) + return rc; + + if (capable(CAP_MAC_OVERRIDE)) + return 0; + + if (sp != smack_known_floor.smk_known) + rc = -EACCES; + + return rc; +} + + +/* + * Superblock Hooks. + */ + +/** + * smack_sb_alloc_security - allocate a superblock blob + * @sb: the superblock getting the blob + * + * Returns 0 on success or -ENOMEM on error. + */ +static int smack_sb_alloc_security(struct super_block *sb) +{ + struct superblock_smack *sbsp; + + sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); + + if (sbsp == NULL) + return -ENOMEM; + + sbsp->smk_root = smack_known_floor.smk_known; + sbsp->smk_default = smack_known_floor.smk_known; + sbsp->smk_floor = smack_known_floor.smk_known; + sbsp->smk_hat = smack_known_hat.smk_known; + sbsp->smk_initialized = 0; + spin_lock_init(&sbsp->smk_sblock); + + sb->s_security = sbsp; + + return 0; +} + +/** + * smack_sb_free_security - free a superblock blob + * @sb: the superblock getting the blob + * + */ +static void smack_sb_free_security(struct super_block *sb) +{ + kfree(sb->s_security); + sb->s_security = NULL; +} + +/** + * smack_sb_copy_data - copy mount options data for processing + * @type: file system type + * @orig: where to start + * @smackopts + * + * Returns 0 on success or -ENOMEM on error. + * + * Copy the Smack specific mount options out of the mount + * options list. + */ +static int smack_sb_copy_data(struct file_system_type *type, void *orig, + void *smackopts) +{ + char *cp, *commap, *otheropts, *dp; + + /* Binary mount data: just copy */ + if (type->fs_flags & FS_BINARY_MOUNTDATA) { + copy_page(smackopts, orig); + return 0; + } + + otheropts = (char *)get_zeroed_page(GFP_KERNEL); + if (otheropts == NULL) + return -ENOMEM; + + for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { + if (strstr(cp, SMK_FSDEFAULT) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSFLOOR) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSHAT) == cp) + dp = smackopts; + else if (strstr(cp, SMK_FSROOT) == cp) + dp = smackopts; + else + dp = otheropts; + + commap = strchr(cp, ','); + if (commap != NULL) + *commap = '\0'; + + if (*dp != '\0') + strcat(dp, ","); + strcat(dp, cp); + } + + strcpy(orig, otheropts); + free_page((unsigned long)otheropts); + + return 0; +} + +/** + * smack_sb_kern_mount - Smack specific mount processing + * @sb: the file system superblock + * @data: the smack mount options + * + * Returns 0 on success, an error code on failure + */ +static int smack_sb_kern_mount(struct super_block *sb, void *data) +{ + struct dentry *root = sb->s_root; + struct inode *inode = root->d_inode; + struct superblock_smack *sp = sb->s_security; + struct inode_smack *isp; + char *op; + char *commap; + char *nsp; + + spin_lock(&sp->smk_sblock); + if (sp->smk_initialized != 0) { + spin_unlock(&sp->smk_sblock); + return 0; + } + sp->smk_initialized = 1; + spin_unlock(&sp->smk_sblock); + + for (op = data; op != NULL; op = commap) { + commap = strchr(op, ','); + if (commap != NULL) + *commap++ = '\0'; + + if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { + op += strlen(SMK_FSHAT); + nsp = smk_import(op, 0); + if (nsp != NULL) + sp->smk_hat = nsp; + } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { + op += strlen(SMK_FSFLOOR); + nsp = smk_import(op, 0); + if (nsp != NULL) + sp->smk_floor = nsp; + } else if (strncmp(op, SMK_FSDEFAULT, + strlen(SMK_FSDEFAULT)) == 0) { + op += strlen(SMK_FSDEFAULT); + nsp = smk_import(op, 0); + if (nsp != NULL) + sp->smk_default = nsp; + } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { + op += strlen(SMK_FSROOT); + nsp = smk_import(op, 0); + if (nsp != NULL) + sp->smk_root = nsp; + } + } + + /* + * Initialize the root inode. + */ + isp = inode->i_security; + if (isp == NULL) + inode->i_security = new_inode_smack(sp->smk_root); + else + isp->smk_inode = sp->smk_root; + + return 0; +} + +/** + * smack_sb_statfs - Smack check on statfs + * @dentry: identifies the file system in question + * + * Returns 0 if current can read the floor of the filesystem, + * and error code otherwise + */ +static int smack_sb_statfs(struct dentry *dentry) +{ + struct superblock_smack *sbp = dentry->d_sb->s_security; + + return smk_curacc(sbp->smk_floor, MAY_READ); +} + +/** + * smack_sb_mount - Smack check for mounting + * @dev_name: unused + * @nd: mount point + * @type: unused + * @flags: unused + * @data: unused + * + * Returns 0 if current can write the floor of the filesystem + * being mounted on, an error code otherwise. + */ +static int smack_sb_mount(char *dev_name, struct nameidata *nd, + char *type, unsigned long flags, void *data) +{ + struct superblock_smack *sbp = nd->mnt->mnt_sb->s_security; + + return smk_curacc(sbp->smk_floor, MAY_WRITE); +} + +/** + * smack_sb_umount - Smack check for unmounting + * @mnt: file system to unmount + * @flags: unused + * + * Returns 0 if current can write the floor of the filesystem + * being unmounted, an error code otherwise. + */ +static int smack_sb_umount(struct vfsmount *mnt, int flags) +{ + struct superblock_smack *sbp; + + sbp = mnt->mnt_sb->s_security; + + return smk_curacc(sbp->smk_floor, MAY_WRITE); +} + +/* + * Inode hooks + */ + +/** + * smack_inode_alloc_security - allocate an inode blob + * @inode - the inode in need of a blob + * + * Returns 0 if it gets a blob, -ENOMEM otherwise + */ +static int smack_inode_alloc_security(struct inode *inode) +{ + inode->i_security = new_inode_smack(current->security); + if (inode->i_security == NULL) + return -ENOMEM; + return 0; +} + +/** + * smack_inode_free_security - free an inode blob + * @inode - the inode with a blob + * + * Clears the blob pointer in inode + */ +static void smack_inode_free_security(struct inode *inode) +{ + kfree(inode->i_security); + inode->i_security = NULL; +} + +/** + * smack_inode_init_security - copy out the smack from an inode + * @inode: the inode + * @dir: unused + * @name: where to put the attribute name + * @value: where to put the attribute value + * @len: where to put the length of the attribute + * + * Returns 0 if it all works out, -ENOMEM if there's no memory + */ +static int smack_inode_init_security(struct inode *inode, struct inode *dir, + char **name, void **value, size_t *len) +{ + char *isp = smk_of_inode(inode); + + if (name) { + *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL); + if (*name == NULL) + return -ENOMEM; + } + + if (value) { + *value = kstrdup(isp, GFP_KERNEL); + if (*value == NULL) + return -ENOMEM; + } + + if (len) + *len = strlen(isp) + 1; + + return 0; +} + +/** + * smack_inode_link - Smack check on link + * @old_dentry: the existing object + * @dir: unused + * @new_dentry: the new object + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *new_dentry) +{ + int rc; + char *isp; + + isp = smk_of_inode(old_dentry->d_inode); + rc = smk_curacc(isp, MAY_WRITE); + + if (rc == 0 && new_dentry->d_inode != NULL) { + isp = smk_of_inode(new_dentry->d_inode); + rc = smk_curacc(isp, MAY_WRITE); + } + + return rc; +} + +/** + * smack_inode_unlink - Smack check on inode deletion + * @dir: containing directory object + * @dentry: file to unlink + * + * Returns 0 if current can write the containing directory + * and the object, error code otherwise + */ +static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) +{ + struct inode *ip = dentry->d_inode; + int rc; + + /* + * You need write access to the thing you're unlinking + */ + rc = smk_curacc(smk_of_inode(ip), MAY_WRITE); + if (rc == 0) + /* + * You also need write access to the containing directory + */ + rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); + + return rc; +} + +/** + * smack_inode_rmdir - Smack check on directory deletion + * @dir: containing directory object + * @dentry: directory to unlink + * + * Returns 0 if current can write the containing directory + * and the directory, error code otherwise + */ +static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) +{ + int rc; + + /* + * You need write access to the thing you're removing + */ + rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); + if (rc == 0) + /* + * You also need write access to the containing directory + */ + rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); + + return rc; +} + +/** + * smack_inode_rename - Smack check on rename + * @old_inode: the old directory + * @old_dentry: unused + * @new_inode: the new directory + * @new_dentry: unused + * + * Read and write access is required on both the old and + * new directories. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_rename(struct inode *old_inode, + struct dentry *old_dentry, + struct inode *new_inode, + struct dentry *new_dentry) +{ + int rc; + char *isp; + + isp = smk_of_inode(old_dentry->d_inode); + rc = smk_curacc(isp, MAY_READWRITE); + + if (rc == 0 && new_dentry->d_inode != NULL) { + isp = smk_of_inode(new_dentry->d_inode); + rc = smk_curacc(isp, MAY_READWRITE); + } + + return rc; +} + +/** + * smack_inode_permission - Smack version of permission() + * @inode: the inode in question + * @mask: the access requested + * @nd: unused + * + * This is the important Smack hook. + * + * Returns 0 if access is permitted, -EACCES otherwise + */ +static int smack_inode_permission(struct inode *inode, int mask, + struct nameidata *nd) +{ + /* + * No permission to check. Existence test. Yup, it's there. + */ + if (mask == 0) + return 0; + + return smk_curacc(smk_of_inode(inode), mask); +} + +/** + * smack_inode_setattr - Smack check for setting attributes + * @dentry: the object + * @iattr: for the force flag + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) +{ + /* + * Need to allow for clearing the setuid bit. + */ + if (iattr->ia_valid & ATTR_FORCE) + return 0; + + return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); +} + +/** + * smack_inode_getattr - Smack check for getting attributes + * @mnt: unused + * @dentry: the object + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) +{ + return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); +} + +/** + * smack_inode_setxattr - Smack check for setting xattrs + * @dentry: the object + * @name: name of the attribute + * @value: unused + * @size: unused + * @flags: unused + * + * This protects the Smack attribute explicitly. + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_setxattr(struct dentry *dentry, char *name, + void *value, size_t size, int flags) +{ + if (!capable(CAP_MAC_ADMIN)) { + if (strcmp(name, XATTR_NAME_SMACK) == 0 || + strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || + strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) + return -EPERM; + } + + return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); +} + +/** + * smack_inode_post_setxattr - Apply the Smack update approved above + * @dentry: object + * @name: attribute name + * @value: attribute value + * @size: attribute size + * @flags: unused + * + * Set the pointer in the inode blob to the entry found + * in the master label list. + */ +static void smack_inode_post_setxattr(struct dentry *dentry, char *name, + void *value, size_t size, int flags) +{ + struct inode_smack *isp; + char *nsp; + + /* + * Not SMACK + */ + if (strcmp(name, XATTR_NAME_SMACK)) + return; + + if (size >= SMK_LABELLEN) + return; + + isp = dentry->d_inode->i_security; + + /* + * No locking is done here. This is a pointer + * assignment. + */ + nsp = smk_import(value, size); + if (nsp != NULL) + isp->smk_inode = nsp; + else + isp->smk_inode = smack_known_invalid.smk_known; + + return; +} + +/* + * smack_inode_getxattr - Smack check on getxattr + * @dentry: the object + * @name: unused + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_getxattr(struct dentry *dentry, char *name) +{ + return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); +} + +/* + * smack_inode_removexattr - Smack check on removexattr + * @dentry: the object + * @name: name of the attribute + * + * Removing the Smack attribute requires CAP_MAC_ADMIN + * + * Returns 0 if access is permitted, an error code otherwise + */ +static int smack_inode_removexattr(struct dentry *dentry, char *name) +{ + if (strcmp(name, XATTR_NAME_SMACK) == 0 && !capable(CAP_MAC_ADMIN)) + return -EPERM; + + return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); +} + +/** + * smack_inode_getsecurity - get smack xattrs + * @inode: the object + * @name: attribute name + * @buffer: where to put the result + * @size: size of the buffer + * @err: unused + * + * Returns the size of the attribute or an error code + */ +static int smack_inode_getsecurity(const struct inode *inode, + const char *name, void **buffer, + bool alloc) +{ + struct socket_smack *ssp; + struct socket *sock; + struct super_block *sbp; + struct inode *ip = (struct inode *)inode; + char *isp; + int ilen; + int rc = 0; + + if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { + isp = smk_of_inode(inode); + ilen = strlen(isp) + 1; + *buffer = isp; + return ilen; + } + + /* + * The rest of the Smack xattrs are only on sockets. + */ + sbp = ip->i_sb; + if (sbp->s_magic != SOCKFS_MAGIC) + return -EOPNOTSUPP; + + sock = SOCKET_I(ip); + if (sock == NULL) + return -EOPNOTSUPP; + + ssp = sock->sk->sk_security; + + if (strcmp(name, XATTR_SMACK_IPIN) == 0) + isp = ssp->smk_in; + else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) + isp = ssp->smk_out; + else + return -EOPNOTSUPP; + + ilen = strlen(isp) + 1; + if (rc == 0) { + *buffer = isp; + rc = ilen; + } + + return rc; +} + + +/** + * smack_inode_listsecurity - list the Smack attributes + * @inode: the object + * @buffer: where they go + * @buffer_size: size of buffer + * + * Returns 0 on success, -EINVAL otherwise + */ +static int smack_inode_listsecurity(struct inode *inode, char *buffer, + size_t buffer_size) +{ + int len = strlen(XATTR_NAME_SMACK); + + if (buffer != NULL && len <= buffer_size) { + memcpy(buffer, XATTR_NAME_SMACK, len); + return len; + } + return -EINVAL; +} + +/* + * File Hooks + */ + +/** + * smack_file_permission - Smack check on file operations + * @file: unused + * @mask: unused + * + * Returns 0 + * + * Should access checks be done on each read or write? + * UNICOS and SELinux say yes. + * Trusted Solaris, Trusted Irix, and just about everyone else says no. + * + * I'll say no for now. Smack does not do the frequent + * label changing that SELinux does. + */ +static int smack_file_permission(struct file *file, int mask) +{ + return 0; +} + +/** + * smack_file_alloc_security - assign a file security blob + * @file: the object + * + * The security blob for a file is a pointer to the master + * label list, so no allocation is done. + * + * Returns 0 + */ +static int smack_file_alloc_security(struct file *file) +{ + file->f_security = current->security; + return 0; +} + +/** + * smack_file_free_security - clear a file security blob + * @file: the object + * + * The security blob for a file is a pointer to the master + * label list, so no memory is freed. + */ +static void smack_file_free_security(struct file *file) +{ + file->f_security = NULL; +} + +/** + * smack_file_ioctl - Smack check on ioctls + * @file: the object + * @cmd: what to do + * @arg: unused + * + * Relies heavily on the correct use of the ioctl command conventions. + * + * Returns 0 if allowed, error code otherwise + */ +static int smack_file_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int rc = 0; + + if (_IOC_DIR(cmd) & _IOC_WRITE) + rc = smk_curacc(file->f_security, MAY_WRITE); + + if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) + rc = smk_curacc(file->f_security, MAY_READ); + + return rc; +} + +/** + * smack_file_lock - Smack check on file locking + * @file: the object + * @cmd unused + * + * Returns 0 if current has write access, error code otherwise + */ +static int smack_file_lock(struct file *file, unsigned int cmd) +{ + return smk_curacc(file->f_security, MAY_WRITE); +} + +/** + * smack_file_fcntl - Smack check on fcntl + * @file: the object + * @cmd: what action to check + * @arg: unused + * + * Returns 0 if current has access, error code otherwise + */ +static int smack_file_fcntl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + int rc; + + switch (cmd) { + case F_DUPFD: + case F_GETFD: + case F_GETFL: + case F_GETLK: + case F_GETOWN: + case F_GETSIG: + rc = smk_curacc(file->f_security, MAY_READ); + break; + case F_SETFD: + case F_SETFL: + case F_SETLK: + case F_SETLKW: + case F_SETOWN: + case F_SETSIG: + rc = smk_curacc(file->f_security, MAY_WRITE); + break; + default: + rc = smk_curacc(file->f_security, MAY_READWRITE); + } + + return rc; +} + +/** + * smack_file_set_fowner - set the file security blob value + * @file: object in question + * + * Returns 0 + * Further research may be required on this one. + */ +static int smack_file_set_fowner(struct file *file) +{ + file->f_security = current->security; + return 0; +} + +/** + * smack_file_send_sigiotask - Smack on sigio + * @tsk: The target task + * @fown: the object the signal come from + * @signum: unused + * + * Allow a privileged task to get signals even if it shouldn't + * + * Returns 0 if a subject with the object's smack could + * write to the task, an error code otherwise. + */ +static int smack_file_send_sigiotask(struct task_struct *tsk, + struct fown_struct *fown, int signum) +{ + struct file *file; + int rc; + + /* + * struct fown_struct is never outside the context of a struct file + */ + file = container_of(fown, struct file, f_owner); + rc = smk_access(file->f_security, tsk->security, MAY_WRITE); + if (rc != 0 && __capable(tsk, CAP_MAC_OVERRIDE)) + return 0; + return rc; +} + +/** + * smack_file_receive - Smack file receive check + * @file: the object + * + * Returns 0 if current has access, error code otherwise + */ +static int smack_file_receive(struct file *file) +{ + int may = 0; + + /* + * This code relies on bitmasks. + */ + if (file->f_mode & FMODE_READ) + may = MAY_READ; + if (file->f_mode & FMODE_WRITE) + may |= MAY_WRITE; + + return smk_curacc(file->f_security, may); +} + +/* + * Task hooks + */ + +/** + * smack_task_alloc_security - "allocate" a task blob + * @tsk: the task in need of a blob + * + * Smack isn't using copies of blobs. Everyone + * points to an immutable list. No alloc required. + * No data copy required. + * + * Always returns 0 + */ +static int smack_task_alloc_security(struct task_struct *tsk) +{ + tsk->security = current->security; + + return 0; +} + +/** + * smack_task_free_security - "free" a task blob + * @task: the task with the blob + * + * Smack isn't using copies of blobs. Everyone + * points to an immutable list. The blobs never go away. + * There is no leak here. + */ +static void smack_task_free_security(struct task_struct *task) +{ + task->security = NULL; +} + +/** + * smack_task_setpgid - Smack check on setting pgid + * @p: the task object + * @pgid: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setpgid(struct task_struct *p, pid_t pgid) +{ + return smk_curacc(p->security, MAY_WRITE); +} + +/** + * smack_task_getpgid - Smack access check for getpgid + * @p: the object task + * + * Returns 0 if current can read the object task, error code otherwise + */ +static int smack_task_getpgid(struct task_struct *p) +{ + return smk_curacc(p->security, MAY_READ); +} + +/** + * smack_task_getsid - Smack access check for getsid + * @p: the object task + * + * Returns 0 if current can read the object task, error code otherwise + */ +static int smack_task_getsid(struct task_struct *p) +{ + return smk_curacc(p->security, MAY_READ); +} + +/** + * smack_task_getsecid - get the secid of the task + * @p: the object task + * @secid: where to put the result + * + * Sets the secid to contain a u32 version of the smack label. + */ +static void smack_task_getsecid(struct task_struct *p, u32 *secid) +{ + *secid = smack_to_secid(p->security); +} + +/** + * smack_task_setnice - Smack check on setting nice + * @p: the task object + * @nice: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setnice(struct task_struct *p, int nice) +{ + return smk_curacc(p->security, MAY_WRITE); +} + +/** + * smack_task_setioprio - Smack check on setting ioprio + * @p: the task object + * @ioprio: unused + * + * Return 0 if write access is permitted + */ +static int smack_task_setioprio(struct task_struct *p, int ioprio) +{ + return smk_curacc(p->security, MAY_WRITE); +} + +/** + * smack_task_getioprio - Smack check on reading ioprio + * @p: the task object + * + * Return 0 if read access is permitted + */ +static int smack_task_getioprio(struct task_struct *p) +{ + return smk_curacc(p->security, MAY_READ); +} + +/** + * smack_task_setscheduler - Smack check on setting scheduler + * @p: the task object + * @policy: unused + * @lp: unused + * + * Return 0 if read access is permitted + */ +static int smack_task_setscheduler(struct task_struct *p, int policy, + struct sched_param *lp) +{ + return smk_curacc(p->security, MAY_WRITE); +} + +/** + * smack_task_getscheduler - Smack check on reading scheduler + * @p: the task object + * + * Return 0 if read access is permitted + */ +static int smack_task_getscheduler(struct task_struct *p) +{ + return smk_curacc(p->security, MAY_READ); +} + +/** + * smack_task_movememory - Smack check on moving memory + * @p: the task object + * + * Return 0 if write access is permitted + */ +static int smack_task_movememory(struct task_struct *p) +{ + return smk_curacc(p->security, MAY_WRITE); +} + +/** + * smack_task_kill - Smack check on signal delivery + * @p: the task object + * @info: unused + * @sig: unused + * @secid: identifies the smack to use in lieu of current's + * + * Return 0 if write access is permitted + * + * The secid behavior is an artifact of an SELinux hack + * in the USB code. Someday it may go away. + */ +static int smack_task_kill(struct task_struct *p, struct siginfo *info, + int sig, u32 secid) +{ + /* + * Special cases where signals really ought to go through + * in spite of policy. Stephen Smalley suggests it may + * make sense to change the caller so that it doesn't + * bother with the LSM hook in these cases. + */ + if (info != SEND_SIG_NOINFO && + (is_si_special(info) || SI_FROMKERNEL(info))) + return 0; + /* + * Sending a signal requires that the sender + * can write the receiver. + */ + if (secid == 0) + return smk_curacc(p->security, MAY_WRITE); + /* + * If the secid isn't 0 we're dealing with some USB IO + * specific behavior. This is not clean. For one thing + * we can't take privilege into account. + */ + return smk_access(smack_from_secid(secid), p->security, MAY_WRITE); +} + +/** + * smack_task_wait - Smack access check for waiting + * @p: task to wait for + * + * Returns 0 if current can wait for p, error code otherwise + */ +static int smack_task_wait(struct task_struct *p) +{ + int rc; + + rc = smk_access(current->security, p->security, MAY_WRITE); + if (rc == 0) + return 0; + + /* + * Allow the operation to succeed if either task + * has privilege to perform operations that might + * account for the smack labels having gotten to + * be different in the first place. + * + * This breaks the strict subjet/object access + * control ideal, taking the object's privilege + * state into account in the decision as well as + * the smack value. + */ + if (capable(CAP_MAC_OVERRIDE) || __capable(p, CAP_MAC_OVERRIDE)) + return 0; + + return rc; +} + +/** + * smack_task_to_inode - copy task smack into the inode blob + * @p: task to copy from + * inode: inode to copy to + * + * Sets the smack pointer in the inode security blob + */ +static void smack_task_to_inode(struct task_struct *p, struct inode *inode) +{ + struct inode_smack *isp = inode->i_security; + isp->smk_inode = p->security; +} + +/* + * Socket hooks. + */ + +/** + * smack_sk_alloc_security - Allocate a socket blob + * @sk: the socket + * @family: unused + * @priority: memory allocation priority + * + * Assign Smack pointers to current + * + * Returns 0 on success, -ENOMEM is there's no memory + */ +static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) +{ + char *csp = current->security; + struct socket_smack *ssp; + + ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); + if (ssp == NULL) + return -ENOMEM; + + ssp->smk_in = csp; + ssp->smk_out = csp; + ssp->smk_packet[0] = '\0'; + + sk->sk_security = ssp; + + return 0; +} + +/** + * smack_sk_free_security - Free a socket blob + * @sk: the socket + * + * Clears the blob pointer + */ +static void smack_sk_free_security(struct sock *sk) +{ + kfree(sk->sk_security); +} + +/** + * smack_set_catset - convert a capset to netlabel mls categories + * @catset: the Smack categories + * @sap: where to put the netlabel categories + * + * Allocates and fills attr.mls.cat + */ +static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap) +{ + unsigned char *cp; + unsigned char m; + int cat; + int rc; + int byte; + + if (catset == 0) + return; + + sap->flags |= NETLBL_SECATTR_MLS_CAT; + sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); + sap->attr.mls.cat->startbit = 0; + + for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++) + for (m = 0x80; m != 0; m >>= 1, cat++) { + if ((m & *cp) == 0) + continue; + rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat, + cat, GFP_ATOMIC); + } +} + +/** + * smack_to_secattr - fill a secattr from a smack value + * @smack: the smack value + * @nlsp: where the result goes + * + * Casey says that CIPSO is good enough for now. + * It can be used to effect. + * It can also be abused to effect when necessary. + * Appologies to the TSIG group in general and GW in particular. + */ +static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp) +{ + struct smack_cipso cipso; + int rc; + + switch (smack_net_nltype) { + case NETLBL_NLTYPE_CIPSOV4: + nlsp->domain = NULL; + nlsp->flags = NETLBL_SECATTR_DOMAIN; + nlsp->flags |= NETLBL_SECATTR_MLS_LVL; + + rc = smack_to_cipso(smack, &cipso); + if (rc == 0) { + nlsp->attr.mls.lvl = cipso.smk_level; + smack_set_catset(cipso.smk_catset, nlsp); + } else { + nlsp->attr.mls.lvl = smack_cipso_direct; + smack_set_catset(smack, nlsp); + } + break; + default: + break; + } +} + +/** + * smack_netlabel - Set the secattr on a socket + * @sk: the socket + * + * Convert the outbound smack value (smk_out) to a + * secattr and attach it to the socket. + * + * Returns 0 on success or an error code + */ +static int smack_netlabel(struct sock *sk) +{ + struct socket_smack *ssp = sk->sk_security; + struct netlbl_lsm_secattr secattr; + int rc = 0; + + netlbl_secattr_init(&secattr); + smack_to_secattr(ssp->smk_out, &secattr); + if (secattr.flags != NETLBL_SECATTR_NONE) + rc = netlbl_sock_setattr(sk, &secattr); + + netlbl_secattr_destroy(&secattr); + return rc; +} + +/** + * smack_inode_setsecurity - set smack xattrs + * @inode: the object + * @name: attribute name + * @value: attribute value + * @size: size of the attribute + * @flags: unused + * + * Sets the named attribute in the appropriate blob + * + * Returns 0 on success, or an error code + */ +static int smack_inode_setsecurity(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + char *sp; + struct inode_smack *nsp = inode->i_security; + struct socket_smack *ssp; + struct socket *sock; + + if (value == NULL || size > SMK_LABELLEN) + return -EACCES; + + sp = smk_import(value, size); + if (sp == NULL) + return -EINVAL; + + if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { + nsp->smk_inode = sp; + return 0; + } + /* + * The rest of the Smack xattrs are only on sockets. + */ + if (inode->i_sb->s_magic != SOCKFS_MAGIC) + return -EOPNOTSUPP; + + sock = SOCKET_I(inode); + if (sock == NULL) + return -EOPNOTSUPP; + + ssp = sock->sk->sk_security; + + if (strcmp(name, XATTR_SMACK_IPIN) == 0) + ssp->smk_in = sp; + else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { + ssp->smk_out = sp; + return smack_netlabel(sock->sk); + } else + return -EOPNOTSUPP; + + return 0; +} + +/** + * smack_socket_post_create - finish socket setup + * @sock: the socket + * @family: protocol family + * @type: unused + * @protocol: unused + * @kern: unused + * + * Sets the netlabel information on the socket + * + * Returns 0 on success, and error code otherwise + */ +static int smack_socket_post_create(struct socket *sock, int family, + int type, int protocol, int kern) +{ + if (family != PF_INET) + return 0; + /* + * Set the outbound netlbl. + */ + return smack_netlabel(sock->sk); +} + +/** + * smack_flags_to_may - convert S_ to MAY_ values + * @flags: the S_ value + * + * Returns the equivalent MAY_ value + */ +static int smack_flags_to_may(int flags) +{ + int may = 0; + + if (flags & S_IRUGO) + may |= MAY_READ; + if (flags & S_IWUGO) + may |= MAY_WRITE; + if (flags & S_IXUGO) + may |= MAY_EXEC; + + return may; +} + +/** + * smack_msg_msg_alloc_security - Set the security blob for msg_msg + * @msg: the object + * + * Returns 0 + */ +static int smack_msg_msg_alloc_security(struct msg_msg *msg) +{ + msg->security = current->security; + return 0; +} + +/** + * smack_msg_msg_free_security - Clear the security blob for msg_msg + * @msg: the object + * + * Clears the blob pointer + */ +static void smack_msg_msg_free_security(struct msg_msg *msg) +{ + msg->security = NULL; +} + +/** + * smack_of_shm - the smack pointer for the shm + * @shp: the object + * + * Returns a pointer to the smack value + */ +static char *smack_of_shm(struct shmid_kernel *shp) +{ + return (char *)shp->shm_perm.security; +} + +/** + * smack_shm_alloc_security - Set the security blob for shm + * @shp: the object + * + * Returns 0 + */ +static int smack_shm_alloc_security(struct shmid_kernel *shp) +{ + struct kern_ipc_perm *isp = &shp->shm_perm; + + isp->security = current->security; + return 0; +} + +/** + * smack_shm_free_security - Clear the security blob for shm + * @shp: the object + * + * Clears the blob pointer + */ +static void smack_shm_free_security(struct shmid_kernel *shp) +{ + struct kern_ipc_perm *isp = &shp->shm_perm; + + isp->security = NULL; +} + +/** + * smack_shm_associate - Smack access check for shm + * @shp: the object + * @shmflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) +{ + char *ssp = smack_of_shm(shp); + int may; + + may = smack_flags_to_may(shmflg); + return smk_curacc(ssp, may); +} + +/** + * smack_shm_shmctl - Smack access check for shm + * @shp: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) +{ + char *ssp = smack_of_shm(shp); + int may; + + switch (cmd) { + case IPC_STAT: + case SHM_STAT: + may = MAY_READ; + break; + case IPC_SET: + case SHM_LOCK: + case SHM_UNLOCK: + case IPC_RMID: + may = MAY_READWRITE; + break; + case IPC_INFO: + case SHM_INFO: + /* + * System level information. + */ + return 0; + default: + return -EINVAL; + } + + return smk_curacc(ssp, may); +} + +/** + * smack_shm_shmat - Smack access for shmat + * @shp: the object + * @shmaddr: unused + * @shmflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, + int shmflg) +{ + char *ssp = smack_of_shm(shp); + int may; + + may = smack_flags_to_may(shmflg); + return smk_curacc(ssp, may); +} + +/** + * smack_of_sem - the smack pointer for the sem + * @sma: the object + * + * Returns a pointer to the smack value + */ +static char *smack_of_sem(struct sem_array *sma) +{ + return (char *)sma->sem_perm.security; +} + +/** + * smack_sem_alloc_security - Set the security blob for sem + * @sma: the object + * + * Returns 0 + */ +static int smack_sem_alloc_security(struct sem_array *sma) +{ + struct kern_ipc_perm *isp = &sma->sem_perm; + + isp->security = current->security; + return 0; +} + +/** + * smack_sem_free_security - Clear the security blob for sem + * @sma: the object + * + * Clears the blob pointer + */ +static void smack_sem_free_security(struct sem_array *sma) +{ + struct kern_ipc_perm *isp = &sma->sem_perm; + + isp->security = NULL; +} + +/** + * smack_sem_associate - Smack access check for sem + * @sma: the object + * @semflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_sem_associate(struct sem_array *sma, int semflg) +{ + char *ssp = smack_of_sem(sma); + int may; + + may = smack_flags_to_may(semflg); + return smk_curacc(ssp, may); +} + +/** + * smack_sem_shmctl - Smack access check for sem + * @sma: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_sem_semctl(struct sem_array *sma, int cmd) +{ + char *ssp = smack_of_sem(sma); + int may; + + switch (cmd) { + case GETPID: + case GETNCNT: + case GETZCNT: + case GETVAL: + case GETALL: + case IPC_STAT: + case SEM_STAT: + may = MAY_READ; + break; + case SETVAL: + case SETALL: + case IPC_RMID: + case IPC_SET: + may = MAY_READWRITE; + break; + case IPC_INFO: + case SEM_INFO: + /* + * System level information + */ + return 0; + default: + return -EINVAL; + } + + return smk_curacc(ssp, may); +} + +/** + * smack_sem_semop - Smack checks of semaphore operations + * @sma: the object + * @sops: unused + * @nsops: unused + * @alter: unused + * + * Treated as read and write in all cases. + * + * Returns 0 if access is allowed, error code otherwise + */ +static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, + unsigned nsops, int alter) +{ + char *ssp = smack_of_sem(sma); + + return smk_curacc(ssp, MAY_READWRITE); +} + +/** + * smack_msg_alloc_security - Set the security blob for msg + * @msq: the object + * + * Returns 0 + */ +static int smack_msg_queue_alloc_security(struct msg_queue *msq) +{ + struct kern_ipc_perm *kisp = &msq->q_perm; + + kisp->security = current->security; + return 0; +} + +/** + * smack_msg_free_security - Clear the security blob for msg + * @msq: the object + * + * Clears the blob pointer + */ +static void smack_msg_queue_free_security(struct msg_queue *msq) +{ + struct kern_ipc_perm *kisp = &msq->q_perm; + + kisp->security = NULL; +} + +/** + * smack_of_msq - the smack pointer for the msq + * @msq: the object + * + * Returns a pointer to the smack value + */ +static char *smack_of_msq(struct msg_queue *msq) +{ + return (char *)msq->q_perm.security; +} + +/** + * smack_msg_queue_associate - Smack access check for msg_queue + * @msq: the object + * @msqflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) +{ + char *msp = smack_of_msq(msq); + int may; + + may = smack_flags_to_may(msqflg); + return smk_curacc(msp, may); +} + +/** + * smack_msg_queue_msgctl - Smack access check for msg_queue + * @msq: the object + * @cmd: what it wants to do + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) +{ + char *msp = smack_of_msq(msq); + int may; + + switch (cmd) { + case IPC_STAT: + case MSG_STAT: + may = MAY_READ; + break; + case IPC_SET: + case IPC_RMID: + may = MAY_READWRITE; + break; + case IPC_INFO: + case MSG_INFO: + /* + * System level information + */ + return 0; + default: + return -EINVAL; + } + + return smk_curacc(msp, may); +} + +/** + * smack_msg_queue_msgsnd - Smack access check for msg_queue + * @msq: the object + * @msg: unused + * @msqflg: access requested + * + * Returns 0 if current has the requested access, error code otherwise + */ +static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, + int msqflg) +{ + char *msp = smack_of_msq(msq); + int rc; + + rc = smack_flags_to_may(msqflg); + return smk_curacc(msp, rc); +} + +/** + * smack_msg_queue_msgsnd - Smack access check for msg_queue + * @msq: the object + * @msg: unused + * @target: unused + * @type: unused + * @mode: unused + * + * Returns 0 if current has read and write access, error code otherwise + */ +static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, + struct task_struct *target, long type, int mode) +{ + char *msp = smack_of_msq(msq); + + return smk_curacc(msp, MAY_READWRITE); +} + +/** + * smack_ipc_permission - Smack access for ipc_permission() + * @ipp: the object permissions + * @flag: access requested + * + * Returns 0 if current has read and write access, error code otherwise + */ +static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) +{ + char *isp = ipp->security; + int may; + + may = smack_flags_to_may(flag); + return smk_curacc(isp, may); +} + +/** + * smack_d_instantiate - Make sure the blob is correct on an inode + * @opt_dentry: unused + * @inode: the object + * + * Set the inode's security blob if it hasn't been done already. + */ +static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) +{ + struct super_block *sbp; + struct superblock_smack *sbsp; + struct inode_smack *isp; + char *csp = current->security; + char *fetched; + char *final; + struct dentry *dp; + + if (inode == NULL) + return; + + isp = inode->i_security; + + mutex_lock(&isp->smk_lock); + /* + * If the inode is already instantiated + * take the quick way out + */ + if (isp->smk_flags & SMK_INODE_INSTANT) + goto unlockandout; + + sbp = inode->i_sb; + sbsp = sbp->s_security; + /* + * We're going to use the superblock default label + * if there's no label on the file. + */ + final = sbsp->smk_default; + + /* + * This is pretty hackish. + * Casey says that we shouldn't have to do + * file system specific code, but it does help + * with keeping it simple. + */ + switch (sbp->s_magic) { + case SMACK_MAGIC: + /* + * Casey says that it's a little embarassing + * that the smack file system doesn't do + * extended attributes. + */ + final = smack_known_star.smk_known; + break; + case PIPEFS_MAGIC: + /* + * Casey says pipes are easy (?) + */ + final = smack_known_star.smk_known; + break; + case DEVPTS_SUPER_MAGIC: + /* + * devpts seems content with the label of the task. + * Programs that change smack have to treat the + * pty with respect. + */ + final = csp; + break; + case SOCKFS_MAGIC: + /* + * Casey says sockets get the smack of the task. + */ + final = csp; + break; + case PROC_SUPER_MAGIC: + /* + * Casey says procfs appears not to care. + * The superblock default suffices. + */ + break; + case TMPFS_MAGIC: + /* + * Device labels should come from the filesystem, + * but watch out, because they're volitile, + * getting recreated on every reboot. + */ + final = smack_known_star.smk_known; + /* + * No break. + * + * If a smack value has been set we want to use it, + * but since tmpfs isn't giving us the opportunity + * to set mount options simulate setting the + * superblock default. + */ + default: + /* + * This isn't an understood special case. + * Get the value from the xattr. + * + * No xattr support means, alas, no SMACK label. + * Use the aforeapplied default. + * It would be curious if the label of the task + * does not match that assigned. + */ + if (inode->i_op->getxattr == NULL) + break; + /* + * Get the dentry for xattr. + */ + if (opt_dentry == NULL) { + dp = d_find_alias(inode); + if (dp == NULL) + break; + } else { + dp = dget(opt_dentry); + if (dp == NULL) + break; + } + + fetched = smk_fetch(inode, dp); + if (fetched != NULL) + final = fetched; + + dput(dp); + break; + } + + if (final == NULL) + isp->smk_inode = csp; + else + isp->smk_inode = final; + + isp->smk_flags |= SMK_INODE_INSTANT; + +unlockandout: + mutex_unlock(&isp->smk_lock); + return; +} + +/** + * smack_getprocattr - Smack process attribute access + * @p: the object task + * @name: the name of the attribute in /proc/.../attr + * @value: where to put the result + * + * Places a copy of the task Smack into value + * + * Returns the length of the smack label or an error code + */ +static int smack_getprocattr(struct task_struct *p, char *name, char **value) +{ + char *cp; + int slen; + + if (strcmp(name, "current") != 0) + return -EINVAL; + + cp = kstrdup(p->security, GFP_KERNEL); + if (cp == NULL) + return -ENOMEM; + + slen = strlen(cp); + *value = cp; + return slen; +} + +/** + * smack_setprocattr - Smack process attribute setting + * @p: the object task + * @name: the name of the attribute in /proc/.../attr + * @value: the value to set + * @size: the size of the value + * + * Sets the Smack value of the task. Only setting self + * is permitted and only with privilege + * + * Returns the length of the smack label or an error code + */ +static int smack_setprocattr(struct task_struct *p, char *name, + void *value, size_t size) +{ + char *newsmack; + + if (!__capable(p, CAP_MAC_ADMIN)) + return -EPERM; + + /* + * Changing another process' Smack value is too dangerous + * and supports no sane use case. + */ + if (p != current) + return -EPERM; + + if (value == NULL || size == 0 || size >= SMK_LABELLEN) + return -EINVAL; + + if (strcmp(name, "current") != 0) + return -EINVAL; + + newsmack = smk_import(value, size); + if (newsmack == NULL) + return -EINVAL; + + p->security = newsmack; + return size; +} + +/** + * smack_unix_stream_connect - Smack access on UDS + * @sock: one socket + * @other: the other socket + * @newsk: unused + * + * Return 0 if a subject with the smack of sock could access + * an object with the smack of other, otherwise an error code + */ +static int smack_unix_stream_connect(struct socket *sock, + struct socket *other, struct sock *newsk) +{ + struct inode *sp = SOCK_INODE(sock); + struct inode *op = SOCK_INODE(other); + + return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE); +} + +/** + * smack_unix_may_send - Smack access on UDS + * @sock: one socket + * @other: the other socket + * + * Return 0 if a subject with the smack of sock could access + * an object with the smack of other, otherwise an error code + */ +static int smack_unix_may_send(struct socket *sock, struct socket *other) +{ + struct inode *sp = SOCK_INODE(sock); + struct inode *op = SOCK_INODE(other); + + return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE); +} + +/** + * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat + * pair to smack + * @sap: netlabel secattr + * @sip: where to put the result + * + * Copies a smack label into sip + */ +static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) +{ + char smack[SMK_LABELLEN]; + int pcat; + + if ((sap->flags & NETLBL_SECATTR_MLS_LVL) == 0) { + /* + * If there are flags but no level netlabel isn't + * behaving the way we expect it to. + * + * Without guidance regarding the smack value + * for the packet fall back on the network + * ambient value. + */ + strncpy(sip, smack_net_ambient, SMK_MAXLEN); + return; + } + /* + * Get the categories, if any + */ + memset(smack, '\0', SMK_LABELLEN); + if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0) + for (pcat = -1;;) { + pcat = netlbl_secattr_catmap_walk(sap->attr.mls.cat, + pcat + 1); + if (pcat < 0) + break; + smack_catset_bit(pcat, smack); + } + /* + * If it is CIPSO using smack direct mapping + * we are already done. WeeHee. + */ + if (sap->attr.mls.lvl == smack_cipso_direct) { + memcpy(sip, smack, SMK_MAXLEN); + return; + } + /* + * Look it up in the supplied table if it is not a direct mapping. + */ + smack_from_cipso(sap->attr.mls.lvl, smack, sip); + return; +} + +/** + * smack_socket_sock_rcv_skb - Smack packet delivery access check + * @sk: socket + * @skb: packet + * + * Returns 0 if the packet should be delivered, an error code otherwise + */ +static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) +{ + struct netlbl_lsm_secattr secattr; + struct socket_smack *ssp = sk->sk_security; + char smack[SMK_LABELLEN]; + int rc; + + if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) + return 0; + + /* + * Translate what netlabel gave us. + */ + memset(smack, '\0', SMK_LABELLEN); + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); + if (rc == 0) + smack_from_secattr(&secattr, smack); + else + strncpy(smack, smack_net_ambient, SMK_MAXLEN); + netlbl_secattr_destroy(&secattr); + /* + * Receiving a packet requires that the other end + * be able to write here. Read access is not required. + * This is the simplist possible security model + * for networking. + */ + return smk_access(smack, ssp->smk_in, MAY_WRITE); +} + +/** + * smack_socket_getpeersec_stream - pull in packet label + * @sock: the socket + * @optval: user's destination + * @optlen: size thereof + * @len: max thereoe + * + * returns zero on success, an error code otherwise + */ +static int smack_socket_getpeersec_stream(struct socket *sock, + char __user *optval, + int __user *optlen, unsigned len) +{ + struct socket_smack *ssp; + int slen; + int rc = 0; + + ssp = sock->sk->sk_security; + slen = strlen(ssp->smk_packet) + 1; + + if (slen > len) + rc = -ERANGE; + else if (copy_to_user(optval, ssp->smk_packet, slen) != 0) + rc = -EFAULT; + + if (put_user(slen, optlen) != 0) + rc = -EFAULT; + + return rc; +} + + +/** + * smack_socket_getpeersec_dgram - pull in packet label + * @sock: the socket + * @skb: packet data + * @secid: pointer to where to put the secid of the packet + * + * Sets the netlabel socket state on sk from parent + */ +static int smack_socket_getpeersec_dgram(struct socket *sock, + struct sk_buff *skb, u32 *secid) + +{ + struct netlbl_lsm_secattr secattr; + struct sock *sk; + char smack[SMK_LABELLEN]; + int family = PF_INET; + u32 s; + int rc; + + /* + * Only works for families with packets. + */ + if (sock != NULL) { + sk = sock->sk; + if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) + return 0; + family = sk->sk_family; + } + /* + * Translate what netlabel gave us. + */ + memset(smack, '\0', SMK_LABELLEN); + netlbl_secattr_init(&secattr); + rc = netlbl_skbuff_getattr(skb, family, &secattr); + if (rc == 0) + smack_from_secattr(&secattr, smack); + netlbl_secattr_destroy(&secattr); + + /* + * Give up if we couldn't get anything + */ + if (rc != 0) + return rc; + + s = smack_to_secid(smack); + if (s == 0) + return -EINVAL; + + *secid = s; + return 0; +} + +/** + * smack_sock_graft - graft access state between two sockets + * @sk: fresh sock + * @parent: donor socket + * + * Sets the netlabel socket state on sk from parent + */ +static void smack_sock_graft(struct sock *sk, struct socket *parent) +{ + struct socket_smack *ssp; + int rc; + + if (sk == NULL) + return; + + if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) + return; + + ssp = sk->sk_security; + ssp->smk_in = current->security; + ssp->smk_out = current->security; + ssp->smk_packet[0] = '\0'; + + rc = smack_netlabel(sk); +} + +/** + * smack_inet_conn_request - Smack access check on connect + * @sk: socket involved + * @skb: packet + * @req: unused + * + * Returns 0 if a task with the packet label could write to + * the socket, otherwise an error code + */ +static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, + struct request_sock *req) +{ + struct netlbl_lsm_secattr skb_secattr; + struct socket_smack *ssp = sk->sk_security; + char smack[SMK_LABELLEN]; + int rc; + + if (skb == NULL) + return -EACCES; + + memset(smack, '\0', SMK_LABELLEN); + netlbl_secattr_init(&skb_secattr); + rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr); + if (rc == 0) + smack_from_secattr(&skb_secattr, smack); + else + strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN); + netlbl_secattr_destroy(&skb_secattr); + /* + * Receiving a packet requires that the other end + * be able to write here. Read access is not required. + * + * If the request is successful save the peer's label + * so that SO_PEERCRED can report it. + */ + rc = smk_access(smack, ssp->smk_in, MAY_WRITE); + if (rc == 0) + strncpy(ssp->smk_packet, smack, SMK_MAXLEN); + + return rc; +} + +/* + * Key management security hooks + * + * Casey has not tested key support very heavily. + * The permission check is most likely too restrictive. + * If you care about keys please have a look. + */ +#ifdef CONFIG_KEYS + +/** + * smack_key_alloc - Set the key security blob + * @key: object + * @tsk: the task associated with the key + * @flags: unused + * + * No allocation required + * + * Returns 0 + */ +static int smack_key_alloc(struct key *key, struct task_struct *tsk, + unsigned long flags) +{ + key->security = tsk->security; + return 0; +} + +/** + * smack_key_free - Clear the key security blob + * @key: the object + * + * Clear the blob pointer + */ +static void smack_key_free(struct key *key) +{ + key->security = NULL; +} + +/* + * smack_key_permission - Smack access on a key + * @key_ref: gets to the object + * @context: task involved + * @perm: unused + * + * Return 0 if the task has read and write to the object, + * an error code otherwise + */ +static int smack_key_permission(key_ref_t key_ref, + struct task_struct *context, key_perm_t perm) +{ + struct key *keyp; + + keyp = key_ref_to_ptr(key_ref); + if (keyp == NULL) + return -EINVAL; + /* + * If the key hasn't been initialized give it access so that + * it may do so. + */ + if (keyp->security == NULL) + return 0; + /* + * This should not occur + */ + if (context->security == NULL) + return -EACCES; + + return smk_access(context->security, keyp->security, MAY_READWRITE); +} +#endif /* CONFIG_KEYS */ + +/* + * smack_secid_to_secctx - return the smack label for a secid + * @secid: incoming integer + * @secdata: destination + * @seclen: how long it is + * + * Exists for networking code. + */ +static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) +{ + char *sp = smack_from_secid(secid); + + *secdata = sp; + *seclen = strlen(sp); + return 0; +} + +/* + * smack_release_secctx - don't do anything. + * @key_ref: unused + * @context: unused + * @perm: unused + * + * Exists to make sure nothing gets done, and properly + */ +static void smack_release_secctx(char *secdata, u32 seclen) +{ +} + +static struct security_operations smack_ops = { + .ptrace = smack_ptrace, + .capget = cap_capget, + .capset_check = cap_capset_check, + .capset_set = cap_capset_set, + .capable = cap_capable, + .syslog = smack_syslog, + .settime = cap_settime, + .vm_enough_memory = cap_vm_enough_memory, + + .bprm_apply_creds = cap_bprm_apply_creds, + .bprm_set_security = cap_bprm_set_security, + .bprm_secureexec = cap_bprm_secureexec, + + .sb_alloc_security = smack_sb_alloc_security, + .sb_free_security = smack_sb_free_security, + .sb_copy_data = smack_sb_copy_data, + .sb_kern_mount = smack_sb_kern_mount, + .sb_statfs = smack_sb_statfs, + .sb_mount = smack_sb_mount, + .sb_umount = smack_sb_umount, + + .inode_alloc_security = smack_inode_alloc_security, + .inode_free_security = smack_inode_free_security, + .inode_init_security = smack_inode_init_security, + .inode_link = smack_inode_link, + .inode_unlink = smack_inode_unlink, + .inode_rmdir = smack_inode_rmdir, + .inode_rename = smack_inode_rename, + .inode_permission = smack_inode_permission, + .inode_setattr = smack_inode_setattr, + .inode_getattr = smack_inode_getattr, + .inode_setxattr = smack_inode_setxattr, + .inode_post_setxattr = smack_inode_post_setxattr, + .inode_getxattr = smack_inode_getxattr, + .inode_removexattr = smack_inode_removexattr, + .inode_getsecurity = smack_inode_getsecurity, + .inode_setsecurity = smack_inode_setsecurity, + .inode_listsecurity = smack_inode_listsecurity, + + .file_permission = smack_file_permission, + .file_alloc_security = smack_file_alloc_security, + .file_free_security = smack_file_free_security, + .file_ioctl = smack_file_ioctl, + .file_lock = smack_file_lock, + .file_fcntl = smack_file_fcntl, + .file_set_fowner = smack_file_set_fowner, + .file_send_sigiotask = smack_file_send_sigiotask, + .file_receive = smack_file_receive, + + .task_alloc_security = smack_task_alloc_security, + .task_free_security = smack_task_free_security, + .task_post_setuid = cap_task_post_setuid, + .task_setpgid = smack_task_setpgid, + .task_getpgid = smack_task_getpgid, + .task_getsid = smack_task_getsid, + .task_getsecid = smack_task_getsecid, + .task_setnice = smack_task_setnice, + .task_setioprio = smack_task_setioprio, + .task_getioprio = smack_task_getioprio, + .task_setscheduler = smack_task_setscheduler, + .task_getscheduler = smack_task_getscheduler, + .task_movememory = smack_task_movememory, + .task_kill = smack_task_kill, + .task_wait = smack_task_wait, + .task_reparent_to_init = cap_task_reparent_to_init, + .task_to_inode = smack_task_to_inode, + + .ipc_permission = smack_ipc_permission, + + .msg_msg_alloc_security = smack_msg_msg_alloc_security, + .msg_msg_free_security = smack_msg_msg_free_security, + + .msg_queue_alloc_security = smack_msg_queue_alloc_security, + .msg_queue_free_security = smack_msg_queue_free_security, + .msg_queue_associate = smack_msg_queue_associate, + .msg_queue_msgctl = smack_msg_queue_msgctl, + .msg_queue_msgsnd = smack_msg_queue_msgsnd, + .msg_queue_msgrcv = smack_msg_queue_msgrcv, + + .shm_alloc_security = smack_shm_alloc_security, + .shm_free_security = smack_shm_free_security, + .shm_associate = smack_shm_associate, + .shm_shmctl = smack_shm_shmctl, + .shm_shmat = smack_shm_shmat, + + .sem_alloc_security = smack_sem_alloc_security, + .sem_free_security = smack_sem_free_security, + .sem_associate = smack_sem_associate, + .sem_semctl = smack_sem_semctl, + .sem_semop = smack_sem_semop, + + .netlink_send = cap_netlink_send, + .netlink_recv = cap_netlink_recv, + + .d_instantiate = smack_d_instantiate, + + .getprocattr = smack_getprocattr, + .setprocattr = smack_setprocattr, + + .unix_stream_connect = smack_unix_stream_connect, + .unix_may_send = smack_unix_may_send, + + .socket_post_create = smack_socket_post_create, + .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, + .socket_getpeersec_stream = smack_socket_getpeersec_stream, + .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, + .sk_alloc_security = smack_sk_alloc_security, + .sk_free_security = smack_sk_free_security, + .sock_graft = smack_sock_graft, + .inet_conn_request = smack_inet_conn_request, + /* key management security hooks */ +#ifdef CONFIG_KEYS + .key_alloc = smack_key_alloc, + .key_free = smack_key_free, + .key_permission = smack_key_permission, +#endif /* CONFIG_KEYS */ + .secid_to_secctx = smack_secid_to_secctx, + .release_secctx = smack_release_secctx, +}; + +/** + * smack_init - initialize the smack system + * + * Returns 0 + */ +static __init int smack_init(void) +{ + printk(KERN_INFO "Smack: Initializing.\n"); + + /* + * Set the security state for the initial task. + */ + current->security = &smack_known_floor.smk_known; + + /* + * Initialize locks + */ + spin_lock_init(&smack_known_unset.smk_cipsolock); + spin_lock_init(&smack_known_huh.smk_cipsolock); + spin_lock_init(&smack_known_hat.smk_cipsolock); + spin_lock_init(&smack_known_star.smk_cipsolock); + spin_lock_init(&smack_known_floor.smk_cipsolock); + spin_lock_init(&smack_known_invalid.smk_cipsolock); + + /* + * Register with LSM + */ + if (register_security(&smack_ops)) + panic("smack: Unable to register with kernel.\n"); + + return 0; +} + +/* + * Smack requires early initialization in order to label + * all processes and objects when they are created. + */ +security_initcall(smack_init); + diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c new file mode 100644 index 000000000000..15aa37f65b39 --- /dev/null +++ b/security/smack/smackfs.c @@ -0,0 +1,981 @@ +/* + * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, version 2. + * + * Authors: + * Casey Schaufler <casey@schaufler-ca.com> + * Ahmed S. Darwish <darwish.07@gmail.com> + * + * Special thanks to the authors of selinuxfs. + * + * Karl MacMillan <kmacmillan@tresys.com> + * James Morris <jmorris@redhat.com> + * + */ + +#include <linux/kernel.h> +#include <linux/vmalloc.h> +#include <linux/security.h> +#include <linux/mutex.h> +#include <net/netlabel.h> +#include <net/cipso_ipv4.h> +#include <linux/seq_file.h> +#include <linux/ctype.h> +#include "smack.h" + +/* + * smackfs pseudo filesystem. + */ + +enum smk_inos { + SMK_ROOT_INO = 2, + SMK_LOAD = 3, /* load policy */ + SMK_CIPSO = 4, /* load label -> CIPSO mapping */ + SMK_DOI = 5, /* CIPSO DOI */ + SMK_DIRECT = 6, /* CIPSO level indicating direct label */ + SMK_AMBIENT = 7, /* internet ambient label */ + SMK_NLTYPE = 8, /* label scheme to use by default */ +}; + +/* + * List locks + */ +static DEFINE_MUTEX(smack_list_lock); +static DEFINE_MUTEX(smack_cipso_lock); + +/* + * This is the "ambient" label for network traffic. + * If it isn't somehow marked, use this. + * It can be reset via smackfs/ambient + */ +char *smack_net_ambient = smack_known_floor.smk_known; + +/* + * This is the default packet marking scheme for network traffic. + * It can be reset via smackfs/nltype + */ +int smack_net_nltype = NETLBL_NLTYPE_CIPSOV4; + +/* + * This is the level in a CIPSO header that indicates a + * smack label is contained directly in the category set. + * It can be reset via smackfs/direct + */ +int smack_cipso_direct = SMACK_CIPSO_DIRECT_DEFAULT; + +static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT; +struct smk_list_entry *smack_list; + +#define SEQ_READ_FINISHED 1 + +/* + * Disable concurrent writing open() operations + */ +static struct semaphore smack_write_sem; + +/* + * Values for parsing cipso rules + * SMK_DIGITLEN: Length of a digit field in a rule. + * SMK_CIPSOMEN: Minimum possible cipso rule length. + */ +#define SMK_DIGITLEN 4 +#define SMK_CIPSOMIN (SMK_MAXLEN + 2 * SMK_DIGITLEN) + +/* + * Seq_file read operations for /smack/load + */ + +static void *load_seq_start(struct seq_file *s, loff_t *pos) +{ + if (*pos == SEQ_READ_FINISHED) + return NULL; + + return smack_list; +} + +static void *load_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct smk_list_entry *skp = ((struct smk_list_entry *) v)->smk_next; + + if (skp == NULL) + *pos = SEQ_READ_FINISHED; + + return skp; +} + +static int load_seq_show(struct seq_file *s, void *v) +{ + struct smk_list_entry *slp = (struct smk_list_entry *) v; + struct smack_rule *srp = &slp->smk_rule; + + seq_printf(s, "%s %s", (char *)srp->smk_subject, + (char *)srp->smk_object); + + seq_putc(s, ' '); + + if (srp->smk_access & MAY_READ) + seq_putc(s, 'r'); + if (srp->smk_access & MAY_WRITE) + seq_putc(s, 'w'); + if (srp->smk_access & MAY_EXEC) + seq_putc(s, 'x'); + if (srp->smk_access & MAY_APPEND) + seq_putc(s, 'a'); + if (srp->smk_access == 0) + seq_putc(s, '-'); + + seq_putc(s, '\n'); + + return 0; +} + +static void load_seq_stop(struct seq_file *s, void *v) +{ + /* No-op */ +} + +static struct seq_operations load_seq_ops = { + .start = load_seq_start, + .next = load_seq_next, + .show = load_seq_show, + .stop = load_seq_stop, +}; + +/** + * smk_open_load - open() for /smack/load + * @inode: inode structure representing file + * @file: "load" file pointer + * + * For reading, use load_seq_* seq_file reading operations. + */ +static int smk_open_load(struct inode *inode, struct file *file) +{ + if ((file->f_flags & O_ACCMODE) == O_RDONLY) + return seq_open(file, &load_seq_ops); + + if (down_interruptible(&smack_write_sem)) + return -ERESTARTSYS; + + return 0; +} + +/** + * smk_release_load - release() for /smack/load + * @inode: inode structure representing file + * @file: "load" file pointer + * + * For a reading session, use the seq_file release + * implementation. + * Otherwise, we are at the end of a writing session so + * clean everything up. + */ +static int smk_release_load(struct inode *inode, struct file *file) +{ + if ((file->f_flags & O_ACCMODE) == O_RDONLY) + return seq_release(inode, file); + + up(&smack_write_sem); + return 0; +} + +/** + * smk_set_access - add a rule to the rule list + * @srp: the new rule to add + * + * Looks through the current subject/object/access list for + * the subject/object pair and replaces the access that was + * there. If the pair isn't found add it with the specified + * access. + */ +static void smk_set_access(struct smack_rule *srp) +{ + struct smk_list_entry *sp; + struct smk_list_entry *newp; + + mutex_lock(&smack_list_lock); + + for (sp = smack_list; sp != NULL; sp = sp->smk_next) + if (sp->smk_rule.smk_subject == srp->smk_subject && + sp->smk_rule.smk_object == srp->smk_object) { + sp->smk_rule.smk_access = srp->smk_access; + break; + } + + if (sp == NULL) { + newp = kzalloc(sizeof(struct smk_list_entry), GFP_KERNEL); + newp->smk_rule = *srp; + newp->smk_next = smack_list; + smack_list = newp; + } + + mutex_unlock(&smack_list_lock); + + return; +} + +/** + * smk_write_load - write() for /smack/load + * @filp: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start - must be 0 + * + * Get one smack access rule from above. + * The format is exactly: + * char subject[SMK_LABELLEN] + * char object[SMK_LABELLEN] + * char access[SMK_ACCESSKINDS] + * + * Anything following is commentary and ignored. + * + * writes must be SMK_LABELLEN+SMK_LABELLEN+4 bytes. + */ +#define MINIMUM_LOAD (SMK_LABELLEN + SMK_LABELLEN + SMK_ACCESSKINDS) + +static ssize_t smk_write_load(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_rule rule; + char *data; + int rc = -EINVAL; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + */ + if (!capable(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (count < MINIMUM_LOAD) + return -EINVAL; + + data = kzalloc(count, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + if (copy_from_user(data, buf, count) != 0) { + rc = -EFAULT; + goto out; + } + + rule.smk_subject = smk_import(data, 0); + if (rule.smk_subject == NULL) + goto out; + + rule.smk_object = smk_import(data + SMK_LABELLEN, 0); + if (rule.smk_object == NULL) + goto out; + + rule.smk_access = 0; + + switch (data[SMK_LABELLEN + SMK_LABELLEN]) { + case '-': + break; + case 'r': + case 'R': + rule.smk_access |= MAY_READ; + break; + default: + goto out; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 1]) { + case '-': + break; + case 'w': + case 'W': + rule.smk_access |= MAY_WRITE; + break; + default: + goto out; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 2]) { + case '-': + break; + case 'x': + case 'X': + rule.smk_access |= MAY_EXEC; + break; + default: + goto out; + } + + switch (data[SMK_LABELLEN + SMK_LABELLEN + 3]) { + case '-': + break; + case 'a': + case 'A': + rule.smk_access |= MAY_READ; + break; + default: + goto out; + } + + smk_set_access(&rule); + rc = count; + +out: + kfree(data); + return rc; +} + +static const struct file_operations smk_load_ops = { + .open = smk_open_load, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_load, + .release = smk_release_load, +}; + +/** + * smk_cipso_doi - initialize the CIPSO domain + */ +void smk_cipso_doi(void) +{ + int rc; + struct cipso_v4_doi *doip; + struct netlbl_audit audit_info; + + rc = netlbl_cfg_map_del(NULL, &audit_info); + if (rc != 0) + printk(KERN_WARNING "%s:%d remove rc = %d\n", + __func__, __LINE__, rc); + + doip = kmalloc(sizeof(struct cipso_v4_doi), GFP_KERNEL); + if (doip == NULL) + panic("smack: Failed to initialize cipso DOI.\n"); + doip->map.std = NULL; + doip->doi = smk_cipso_doi_value; + doip->type = CIPSO_V4_MAP_PASS; + doip->tags[0] = CIPSO_V4_TAG_RBITMAP; + for (rc = 1; rc < CIPSO_V4_TAG_MAXCNT; rc++) + doip->tags[rc] = CIPSO_V4_TAG_INVALID; + + rc = netlbl_cfg_cipsov4_add_map(doip, NULL, &audit_info); + if (rc != 0) + printk(KERN_WARNING "%s:%d add rc = %d\n", + __func__, __LINE__, rc); +} + +/* + * Seq_file read operations for /smack/cipso + */ + +static void *cipso_seq_start(struct seq_file *s, loff_t *pos) +{ + if (*pos == SEQ_READ_FINISHED) + return NULL; + + return smack_known; +} + +static void *cipso_seq_next(struct seq_file *s, void *v, loff_t *pos) +{ + struct smack_known *skp = ((struct smack_known *) v)->smk_next; + + /* + * Omit labels with no associated cipso value + */ + while (skp != NULL && !skp->smk_cipso) + skp = skp->smk_next; + + if (skp == NULL) + *pos = SEQ_READ_FINISHED; + + return skp; +} + +/* + * Print cipso labels in format: + * label level[/cat[,cat]] + */ +static int cipso_seq_show(struct seq_file *s, void *v) +{ + struct smack_known *skp = (struct smack_known *) v; + struct smack_cipso *scp = skp->smk_cipso; + char *cbp; + char sep = '/'; + int cat = 1; + int i; + unsigned char m; + + if (scp == NULL) + return 0; + + seq_printf(s, "%s %3d", (char *)&skp->smk_known, scp->smk_level); + + cbp = scp->smk_catset; + for (i = 0; i < SMK_LABELLEN; i++) + for (m = 0x80; m != 0; m >>= 1) { + if (m & cbp[i]) { + seq_printf(s, "%c%d", sep, cat); + sep = ','; + } + cat++; + } + + seq_putc(s, '\n'); + + return 0; +} + +static void cipso_seq_stop(struct seq_file *s, void *v) +{ + /* No-op */ +} + +static struct seq_operations cipso_seq_ops = { + .start = cipso_seq_start, + .stop = cipso_seq_stop, + .next = cipso_seq_next, + .show = cipso_seq_show, +}; + +/** + * smk_open_cipso - open() for /smack/cipso + * @inode: inode structure representing file + * @file: "cipso" file pointer + * + * Connect our cipso_seq_* operations with /smack/cipso + * file_operations + */ +static int smk_open_cipso(struct inode *inode, struct file *file) +{ + return seq_open(file, &cipso_seq_ops); +} + +/** + * smk_write_cipso - write() for /smack/cipso + * @filp: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Accepts only one cipso rule per write call. + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_cipso(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct smack_known *skp; + struct smack_cipso *scp = NULL; + char mapcatset[SMK_LABELLEN]; + int maplevel; + int cat; + int catlen; + ssize_t rc = -EINVAL; + char *data = NULL; + char *rule; + int ret; + int i; + + /* + * Must have privilege. + * No partial writes. + * Enough data must be present. + */ + if (!capable(CAP_MAC_ADMIN)) + return -EPERM; + if (*ppos != 0) + return -EINVAL; + if (count <= SMK_CIPSOMIN) + return -EINVAL; + + data = kzalloc(count + 1, GFP_KERNEL); + if (data == NULL) + return -ENOMEM; + + if (copy_from_user(data, buf, count) != 0) { + rc = -EFAULT; + goto unlockedout; + } + + data[count] = '\0'; + rule = data; + /* + * Only allow one writer at a time. Writes should be + * quite rare and small in any case. + */ + mutex_lock(&smack_cipso_lock); + + skp = smk_import_entry(rule, 0); + if (skp == NULL) + goto out; + + rule += SMK_LABELLEN;; + ret = sscanf(rule, "%d", &maplevel); + if (ret != 1 || maplevel > SMACK_CIPSO_MAXLEVEL) + goto out; + + rule += SMK_DIGITLEN; + ret = sscanf(rule, "%d", &catlen); + if (ret != 1 || catlen > SMACK_CIPSO_MAXCATNUM) + goto out; + + if (count <= (SMK_CIPSOMIN + catlen * SMK_DIGITLEN)) + goto out; + + memset(mapcatset, 0, sizeof(mapcatset)); + + for (i = 0; i < catlen; i++) { + rule += SMK_DIGITLEN; + ret = sscanf(rule, "%d", &cat); + if (ret != 1 || cat > SMACK_CIPSO_MAXCATVAL) + goto out; + + smack_catset_bit(cat, mapcatset); + } + + if (skp->smk_cipso == NULL) { + scp = kzalloc(sizeof(struct smack_cipso), GFP_KERNEL); + if (scp == NULL) { + rc = -ENOMEM; + goto out; + } + } + + spin_lock_bh(&skp->smk_cipsolock); + + if (scp == NULL) + scp = skp->smk_cipso; + else + skp->smk_cipso = scp; + + scp->smk_level = maplevel; + memcpy(scp->smk_catset, mapcatset, sizeof(mapcatset)); + + spin_unlock_bh(&skp->smk_cipsolock); + + rc = count; +out: + mutex_unlock(&smack_cipso_lock); +unlockedout: + kfree(data); + return rc; +} + +static const struct file_operations smk_cipso_ops = { + .open = smk_open_cipso, + .read = seq_read, + .llseek = seq_lseek, + .write = smk_write_cipso, + .release = seq_release, +}; + +/** + * smk_read_doi - read() for /smack/doi + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_doi(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", smk_cipso_doi_value); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * smk_write_doi - write() for /smack/doi + * @filp: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_doi(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + int i; + + if (!capable(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + + smk_cipso_doi_value = i; + + smk_cipso_doi(); + + return count; +} + +static const struct file_operations smk_doi_ops = { + .read = smk_read_doi, + .write = smk_write_doi, +}; + +/** + * smk_read_direct - read() for /smack/direct + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_direct(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + ssize_t rc; + + if (*ppos != 0) + return 0; + + sprintf(temp, "%d", smack_cipso_direct); + rc = simple_read_from_buffer(buf, count, ppos, temp, strlen(temp)); + + return rc; +} + +/** + * smk_write_direct - write() for /smack/direct + * @filp: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_direct(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char temp[80]; + int i; + + if (!capable(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= sizeof(temp) || count == 0) + return -EINVAL; + + if (copy_from_user(temp, buf, count) != 0) + return -EFAULT; + + temp[count] = '\0'; + + if (sscanf(temp, "%d", &i) != 1) + return -EINVAL; + + smack_cipso_direct = i; + + return count; +} + +static const struct file_operations smk_direct_ops = { + .read = smk_read_direct, + .write = smk_write_direct, +}; + +/** + * smk_read_ambient - read() for /smack/ambient + * @filp: file pointer, not actually used + * @buf: where to put the result + * @cn: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_ambient(struct file *filp, char __user *buf, + size_t cn, loff_t *ppos) +{ + ssize_t rc; + char out[SMK_LABELLEN]; + int asize; + + if (*ppos != 0) + return 0; + /* + * Being careful to avoid a problem in the case where + * smack_net_ambient gets changed in midstream. + * Since smack_net_ambient is always set with a value + * from the label list, including initially, and those + * never get freed, the worst case is that the pointer + * gets changed just after this strncpy, in which case + * the value passed up is incorrect. Locking around + * smack_net_ambient wouldn't be any better than this + * copy scheme as by the time the caller got to look + * at the ambient value it would have cleared the lock + * and been changed. + */ + strncpy(out, smack_net_ambient, SMK_LABELLEN); + asize = strlen(out) + 1; + + if (cn < asize) + return -EINVAL; + + rc = simple_read_from_buffer(buf, cn, ppos, out, asize); + + return rc; +} + +/** + * smk_write_ambient - write() for /smack/ambient + * @filp: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_ambient(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char in[SMK_LABELLEN]; + char *smack; + + if (!capable(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= SMK_LABELLEN) + return -EINVAL; + + if (copy_from_user(in, buf, count) != 0) + return -EFAULT; + + smack = smk_import(in, count); + if (smack == NULL) + return -EINVAL; + + smack_net_ambient = smack; + + return count; +} + +static const struct file_operations smk_ambient_ops = { + .read = smk_read_ambient, + .write = smk_write_ambient, +}; + +struct option_names { + int o_number; + char *o_name; + char *o_alias; +}; + +static struct option_names netlbl_choices[] = { + { NETLBL_NLTYPE_RIPSO, + NETLBL_NLTYPE_RIPSO_NAME, "ripso" }, + { NETLBL_NLTYPE_CIPSOV4, + NETLBL_NLTYPE_CIPSOV4_NAME, "cipsov4" }, + { NETLBL_NLTYPE_CIPSOV4, + NETLBL_NLTYPE_CIPSOV4_NAME, "cipso" }, + { NETLBL_NLTYPE_CIPSOV6, + NETLBL_NLTYPE_CIPSOV6_NAME, "cipsov6" }, + { NETLBL_NLTYPE_UNLABELED, + NETLBL_NLTYPE_UNLABELED_NAME, "unlabeled" }, +}; + +/** + * smk_read_nltype - read() for /smack/nltype + * @filp: file pointer, not actually used + * @buf: where to put the result + * @count: maximum to send along + * @ppos: where to start + * + * Returns number of bytes read or error code, as appropriate + */ +static ssize_t smk_read_nltype(struct file *filp, char __user *buf, + size_t count, loff_t *ppos) +{ + char bound[40]; + ssize_t rc; + int i; + + if (count < SMK_LABELLEN) + return -EINVAL; + + if (*ppos != 0) + return 0; + + sprintf(bound, "unknown"); + + for (i = 0; i < ARRAY_SIZE(netlbl_choices); i++) + if (smack_net_nltype == netlbl_choices[i].o_number) { + sprintf(bound, "%s", netlbl_choices[i].o_name); + break; + } + + rc = simple_read_from_buffer(buf, count, ppos, bound, strlen(bound)); + + return rc; +} + +/** + * smk_write_nltype - write() for /smack/nltype + * @filp: file pointer, not actually used + * @buf: where to get the data from + * @count: bytes sent + * @ppos: where to start + * + * Returns number of bytes written or error code, as appropriate + */ +static ssize_t smk_write_nltype(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + char bound[40]; + char *cp; + int i; + + if (!capable(CAP_MAC_ADMIN)) + return -EPERM; + + if (count >= 40) + return -EINVAL; + + if (copy_from_user(bound, buf, count) != 0) + return -EFAULT; + + bound[count] = '\0'; + cp = strchr(bound, ' '); + if (cp != NULL) + *cp = '\0'; + cp = strchr(bound, '\n'); + if (cp != NULL) + *cp = '\0'; + + for (i = 0; i < ARRAY_SIZE(netlbl_choices); i++) + if (strcmp(bound, netlbl_choices[i].o_name) == 0 || + strcmp(bound, netlbl_choices[i].o_alias) == 0) { + smack_net_nltype = netlbl_choices[i].o_number; + return count; + } + /* + * Not a valid choice. + */ + return -EINVAL; +} + +static const struct file_operations smk_nltype_ops = { + .read = smk_read_nltype, + .write = smk_write_nltype, +}; + +/** + * smk_fill_super - fill the /smackfs superblock + * @sb: the empty superblock + * @data: unused + * @silent: unused + * + * Fill in the well known entries for /smack + * + * Returns 0 on success, an error code on failure + */ +static int smk_fill_super(struct super_block *sb, void *data, int silent) +{ + int rc; + struct inode *root_inode; + + static struct tree_descr smack_files[] = { + [SMK_LOAD] = + {"load", &smk_load_ops, S_IRUGO|S_IWUSR}, + [SMK_CIPSO] = + {"cipso", &smk_cipso_ops, S_IRUGO|S_IWUSR}, + [SMK_DOI] = + {"doi", &smk_doi_ops, S_IRUGO|S_IWUSR}, + [SMK_DIRECT] = + {"direct", &smk_direct_ops, S_IRUGO|S_IWUSR}, + [SMK_AMBIENT] = + {"ambient", &smk_ambient_ops, S_IRUGO|S_IWUSR}, + [SMK_NLTYPE] = + {"nltype", &smk_nltype_ops, S_IRUGO|S_IWUSR}, + /* last one */ {""} + }; + + rc = simple_fill_super(sb, SMACK_MAGIC, smack_files); + if (rc != 0) { + printk(KERN_ERR "%s failed %d while creating inodes\n", + __func__, rc); + return rc; + } + + root_inode = sb->s_root->d_inode; + root_inode->i_security = new_inode_smack(smack_known_floor.smk_known); + + return 0; +} + +/** + * smk_get_sb - get the smackfs superblock + * @fs_type: passed along without comment + * @flags: passed along without comment + * @dev_name: passed along without comment + * @data: passed along without comment + * @mnt: passed along without comment + * + * Just passes everything along. + * + * Returns what the lower level code does. + */ +static int smk_get_sb(struct file_system_type *fs_type, + int flags, const char *dev_name, void *data, + struct vfsmount *mnt) +{ + return get_sb_single(fs_type, flags, data, smk_fill_super, mnt); +} + +static struct file_system_type smk_fs_type = { + .name = "smackfs", + .get_sb = smk_get_sb, + .kill_sb = kill_litter_super, +}; + +static struct vfsmount *smackfs_mount; + +/** + * init_smk_fs - get the smackfs superblock + * + * register the smackfs + * + * Returns 0 unless the registration fails. + */ +static int __init init_smk_fs(void) +{ + int err; + + err = register_filesystem(&smk_fs_type); + if (!err) { + smackfs_mount = kern_mount(&smk_fs_type); + if (IS_ERR(smackfs_mount)) { + printk(KERN_ERR "smackfs: could not mount!\n"); + err = PTR_ERR(smackfs_mount); + smackfs_mount = NULL; + } + } + + sema_init(&smack_write_sem, 1); + smk_cipso_doi(); + + return err; +} + +__initcall(init_smk_fs); |