diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/Kconfig | 11 | ||||
| -rw-r--r-- | security/integrity/evm/evm_main.c | 12 | ||||
| -rw-r--r-- | security/integrity/ima/ima_kexec.c | 2 | ||||
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 4 | ||||
| -rw-r--r-- | security/loadpin/Kconfig | 16 | ||||
| -rw-r--r-- | security/loadpin/loadpin.c | 167 | ||||
| -rw-r--r-- | security/safesetid/lsm.c | 39 | ||||
| -rw-r--r-- | security/security.c | 10 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 28 | ||||
| -rw-r--r-- | security/selinux/include/audit.h | 2 | ||||
| -rw-r--r-- | security/selinux/include/avc.h | 2 | ||||
| -rw-r--r-- | security/selinux/ss/policydb.h | 2 | ||||
| -rw-r--r-- | security/selinux/ss/services.c | 9 | ||||
| -rw-r--r-- | security/smack/smack_access.c | 7 | ||||
| -rw-r--r-- | security/smack/smack_lsm.c | 7 |
15 files changed, 257 insertions, 61 deletions
diff --git a/security/Kconfig b/security/Kconfig index f29e4c656983..e6db09a779b7 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -54,17 +54,6 @@ config SECURITY_NETWORK implement socket and networking access controls. If you are unsure how to answer this question, answer N. -config PAGE_TABLE_ISOLATION - bool "Remove the kernel mapping in user mode" - default y - depends on (X86_64 || X86_PAE) && !UML - help - This feature reduces the number of hardware side channels by - ensuring that the majority of kernel addresses are not mapped - into userspace. - - See Documentation/x86/pti.rst for more details. - config SECURITY_INFINIBAND bool "Infiniband Security Hooks" depends on SECURITY && INFINIBAND diff --git a/security/integrity/evm/evm_main.c b/security/integrity/evm/evm_main.c index 397fea5b3fa6..2e6fb6e2ffd2 100644 --- a/security/integrity/evm/evm_main.c +++ b/security/integrity/evm/evm_main.c @@ -749,13 +749,14 @@ void evm_inode_post_removexattr(struct dentry *dentry, const char *xattr_name) evm_update_evmxattr(dentry, xattr_name, NULL, 0); } -static int evm_attr_change(struct dentry *dentry, struct iattr *attr) +static int evm_attr_change(struct user_namespace *mnt_userns, + struct dentry *dentry, struct iattr *attr) { struct inode *inode = d_backing_inode(dentry); unsigned int ia_valid = attr->ia_valid; - if ((!(ia_valid & ATTR_UID) || uid_eq(attr->ia_uid, inode->i_uid)) && - (!(ia_valid & ATTR_GID) || gid_eq(attr->ia_gid, inode->i_gid)) && + if (!i_uid_needs_update(mnt_userns, attr, inode) && + !i_gid_needs_update(mnt_userns, attr, inode) && (!(ia_valid & ATTR_MODE) || attr->ia_mode == inode->i_mode)) return 0; @@ -769,7 +770,8 @@ static int evm_attr_change(struct dentry *dentry, struct iattr *attr) * Permit update of file attributes when files have a valid EVM signature, * except in the case of them having an immutable portable signature. */ -int evm_inode_setattr(struct dentry *dentry, struct iattr *attr) +int evm_inode_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, + struct iattr *attr) { unsigned int ia_valid = attr->ia_valid; enum integrity_status evm_status; @@ -795,7 +797,7 @@ int evm_inode_setattr(struct dentry *dentry, struct iattr *attr) return 0; if (evm_status == INTEGRITY_PASS_IMMUTABLE && - !evm_attr_change(dentry, attr)) + !evm_attr_change(mnt_userns, dentry, attr)) return 0; integrity_audit_msg(AUDIT_INTEGRITY_METADATA, d_backing_inode(dentry), diff --git a/security/integrity/ima/ima_kexec.c b/security/integrity/ima/ima_kexec.c index 13753136f03f..419dc405c831 100644 --- a/security/integrity/ima/ima_kexec.c +++ b/security/integrity/ima/ima_kexec.c @@ -137,7 +137,7 @@ void ima_add_kexec_buffer(struct kimage *image) /* * Restore the measurement list from the previous kernel. */ -void ima_load_kexec_buffer(void) +void __init ima_load_kexec_buffer(void) { void *kexec_buffer = NULL; size_t kexec_buffer_size = 0; diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index 73917413365b..a8802b8da946 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -2247,6 +2247,10 @@ bool ima_appraise_signature(enum kernel_read_file_id id) if (id >= READING_MAX_ID) return false; + if (id == READING_KEXEC_IMAGE && !(ima_appraise & IMA_APPRAISE_ENFORCE) + && security_locked_down(LOCKDOWN_KEXEC)) + return false; + func = read_idmap[id] ?: FILE_CHECK; rcu_read_lock(); diff --git a/security/loadpin/Kconfig b/security/loadpin/Kconfig index 91be65dec2ab..70e7985b2561 100644 --- a/security/loadpin/Kconfig +++ b/security/loadpin/Kconfig @@ -18,3 +18,19 @@ config SECURITY_LOADPIN_ENFORCE If selected, LoadPin will enforce pinning at boot. If not selected, it can be enabled at boot with the kernel parameter "loadpin.enforce=1". + +config SECURITY_LOADPIN_VERITY + bool "Allow reading files from certain other filesystems that use dm-verity" + depends on SECURITY_LOADPIN && DM_VERITY=y && SECURITYFS + help + If selected LoadPin can allow reading files from filesystems + that use dm-verity. LoadPin maintains a list of verity root + digests it considers trusted. A verity backed filesystem is + considered trusted if its root digest is found in the list + of trusted digests. + + The list of trusted verity can be populated through an ioctl + on the LoadPin securityfs entry 'dm-verity'. The ioctl + expects a file descriptor of a file with verity digests as + parameter. The file must be located on the pinned root and + contain a comma separated list of digests. diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c index ad4e6756c038..6ab5f2bbf41f 100644 --- a/security/loadpin/loadpin.c +++ b/security/loadpin/loadpin.c @@ -18,6 +18,8 @@ #include <linux/path.h> #include <linux/sched.h> /* current */ #include <linux/string_helpers.h> +#include <linux/dm-verity-loadpin.h> +#include <uapi/linux/loadpin.h> static void report_load(const char *origin, struct file *file, char *operation) { @@ -43,6 +45,9 @@ static char *exclude_read_files[READING_MAX_ID]; static int ignore_read_file_id[READING_MAX_ID] __ro_after_init; static struct super_block *pinned_root; static DEFINE_SPINLOCK(pinned_root_spinlock); +#ifdef CONFIG_SECURITY_LOADPIN_VERITY +static bool deny_reading_verity_digests; +#endif #ifdef CONFIG_SYSCTL @@ -171,7 +176,8 @@ static int loadpin_read_file(struct file *file, enum kernel_read_file_id id, spin_unlock(&pinned_root_spinlock); } - if (IS_ERR_OR_NULL(pinned_root) || load_root != pinned_root) { + if (IS_ERR_OR_NULL(pinned_root) || + ((load_root != pinned_root) && !dm_verity_loadpin_is_bdev_trusted(load_root->s_bdev))) { if (unlikely(!enforce)) { report_load(origin, file, "pinning-ignored"); return 0; @@ -237,6 +243,7 @@ static int __init loadpin_init(void) enforce ? "" : "not "); parse_exclude(); security_add_hooks(loadpin_hooks, ARRAY_SIZE(loadpin_hooks), "loadpin"); + return 0; } @@ -245,6 +252,164 @@ DEFINE_LSM(loadpin) = { .init = loadpin_init, }; +#ifdef CONFIG_SECURITY_LOADPIN_VERITY + +enum loadpin_securityfs_interface_index { + LOADPIN_DM_VERITY, +}; + +static int read_trusted_verity_root_digests(unsigned int fd) +{ + struct fd f; + void *data; + int rc; + char *p, *d; + + if (deny_reading_verity_digests) + return -EPERM; + + /* The list of trusted root digests can only be set up once */ + if (!list_empty(&dm_verity_loadpin_trusted_root_digests)) + return -EPERM; + + f = fdget(fd); + if (!f.file) + return -EINVAL; + + data = kzalloc(SZ_4K, GFP_KERNEL); + if (!data) { + rc = -ENOMEM; + goto err; + } + + rc = kernel_read_file(f.file, 0, (void **)&data, SZ_4K - 1, NULL, READING_POLICY); + if (rc < 0) + goto err; + + p = data; + p[rc] = '\0'; + p = strim(p); + + p = strim(data); + while ((d = strsep(&p, "\n")) != NULL) { + int len = strlen(d); + struct dm_verity_loadpin_trusted_root_digest *trd; + + if (len % 2) { + rc = -EPROTO; + goto err; + } + + len /= 2; + + trd = kzalloc(struct_size(trd, data, len), GFP_KERNEL); + if (!trd) { + rc = -ENOMEM; + goto err; + } + + if (hex2bin(trd->data, d, len)) { + kfree(trd); + rc = -EPROTO; + goto err; + } + + trd->len = len; + + list_add_tail(&trd->node, &dm_verity_loadpin_trusted_root_digests); + } + + if (list_empty(&dm_verity_loadpin_trusted_root_digests)) { + rc = -EPROTO; + goto err; + } + + kfree(data); + fdput(f); + + return 0; + +err: + kfree(data); + + /* any failure in loading/parsing invalidates the entire list */ + { + struct dm_verity_loadpin_trusted_root_digest *trd, *tmp; + + list_for_each_entry_safe(trd, tmp, &dm_verity_loadpin_trusted_root_digests, node) { + list_del(&trd->node); + kfree(trd); + } + } + + /* disallow further attempts after reading a corrupt/invalid file */ + deny_reading_verity_digests = true; + + fdput(f); + + return rc; +} + +/******************************** securityfs ********************************/ + +static long dm_verity_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + void __user *uarg = (void __user *)arg; + unsigned int fd; + int rc; + + switch (cmd) { + case LOADPIN_IOC_SET_TRUSTED_VERITY_DIGESTS: + rc = copy_from_user(&fd, uarg, sizeof(fd)); + if (rc) + return rc; + + return read_trusted_verity_root_digests(fd); + + default: + return -EINVAL; + } +} + +static const struct file_operations loadpin_dm_verity_ops = { + .unlocked_ioctl = dm_verity_ioctl, + .compat_ioctl = compat_ptr_ioctl, +}; + +/** + * init_loadpin_securityfs - create the securityfs directory for LoadPin + * + * We can not put this method normally under the loadpin_init() code path since + * the security subsystem gets initialized before the vfs caches. + * + * Returns 0 if the securityfs directory creation was successful. + */ +static int __init init_loadpin_securityfs(void) +{ + struct dentry *loadpin_dir, *dentry; + + loadpin_dir = securityfs_create_dir("loadpin", NULL); + if (IS_ERR(loadpin_dir)) { + pr_err("LoadPin: could not create securityfs dir: %ld\n", + PTR_ERR(loadpin_dir)); + return PTR_ERR(loadpin_dir); + } + + dentry = securityfs_create_file("dm-verity", 0600, loadpin_dir, + (void *)LOADPIN_DM_VERITY, &loadpin_dm_verity_ops); + if (IS_ERR(dentry)) { + pr_err("LoadPin: could not create securityfs entry 'dm-verity': %ld\n", + PTR_ERR(dentry)); + return PTR_ERR(dentry); + } + + return 0; +} + +fs_initcall(init_loadpin_securityfs); + +#endif /* CONFIG_SECURITY_LOADPIN_VERITY */ + /* Should not be mutable after boot, so not listed in sysfs (perm == 0). */ module_param(enforce, int, 0); MODULE_PARM_DESC(enforce, "Enforce module/firmware pinning"); diff --git a/security/safesetid/lsm.c b/security/safesetid/lsm.c index 963f4ad9cb66..e806739f7868 100644 --- a/security/safesetid/lsm.c +++ b/security/safesetid/lsm.c @@ -97,15 +97,9 @@ static int safesetid_security_capable(const struct cred *cred, return 0; /* - * If CAP_SET{U/G}ID is currently used for a setid() syscall, we want to - * let it go through here; the real security check happens later, in the - * task_fix_set{u/g}id hook. - * - * NOTE: - * Until we add support for restricting setgroups() calls, GID security - * policies offer no meaningful security since we always return 0 here - * when called from within the setgroups() syscall and there is no - * additional hook later on to enforce security policies for setgroups(). + * If CAP_SET{U/G}ID is currently used for a setid or setgroups syscall, we + * want to let it go through here; the real security check happens later, in + * the task_fix_set{u/g}id or task_fix_setgroups hooks. */ if ((opts & CAP_OPT_INSETID) != 0) return 0; @@ -241,9 +235,36 @@ static int safesetid_task_fix_setgid(struct cred *new, return -EACCES; } +static int safesetid_task_fix_setgroups(struct cred *new, const struct cred *old) +{ + int i; + + /* Do nothing if there are no setgid restrictions for our old RGID. */ + if (setid_policy_lookup((kid_t){.gid = old->gid}, INVALID_ID, GID) == SIDPOL_DEFAULT) + return 0; + + get_group_info(new->group_info); + for (i = 0; i < new->group_info->ngroups; i++) { + if (!id_permitted_for_cred(old, (kid_t){.gid = new->group_info->gid[i]}, GID)) { + put_group_info(new->group_info); + /* + * Kill this process to avoid potential security vulnerabilities + * that could arise from a missing allowlist entry preventing a + * privileged process from dropping to a lesser-privileged one. + */ + force_sig(SIGKILL); + return -EACCES; + } + } + + put_group_info(new->group_info); + return 0; +} + static struct security_hook_list safesetid_security_hooks[] = { LSM_HOOK_INIT(task_fix_setuid, safesetid_task_fix_setuid), LSM_HOOK_INIT(task_fix_setgid, safesetid_task_fix_setgid), + LSM_HOOK_INIT(task_fix_setgroups, safesetid_task_fix_setgroups), LSM_HOOK_INIT(capable, safesetid_security_capable) }; diff --git a/security/security.c b/security/security.c index 188b8f782220..14d30fec8a00 100644 --- a/security/security.c +++ b/security/security.c @@ -1324,7 +1324,8 @@ int security_inode_permission(struct inode *inode, int mask) return call_int_hook(inode_permission, 0, inode, mask); } -int security_inode_setattr(struct dentry *dentry, struct iattr *attr) +int security_inode_setattr(struct user_namespace *mnt_userns, + struct dentry *dentry, struct iattr *attr) { int ret; @@ -1333,7 +1334,7 @@ int security_inode_setattr(struct dentry *dentry, struct iattr *attr) ret = call_int_hook(inode_setattr, 0, dentry, attr); if (ret) return ret; - return evm_inode_setattr(dentry, attr); + return evm_inode_setattr(mnt_userns, dentry, attr); } EXPORT_SYMBOL_GPL(security_inode_setattr); @@ -1803,6 +1804,11 @@ int security_task_fix_setgid(struct cred *new, const struct cred *old, return call_int_hook(task_fix_setgid, 0, new, old, flags); } +int security_task_fix_setgroups(struct cred *new, const struct cred *old) +{ + return call_int_hook(task_fix_setgroups, 0, new, old); +} + int security_task_setpgid(struct task_struct *p, pid_t pgid) { return call_int_hook(task_setpgid, 0, p, pgid); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index beceb89f68d9..79573504783b 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -640,7 +640,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, * we need to skip the double mount verification. * * This does open a hole in which we will not notice if the first - * mount using this sb set explict options and a second mount using + * mount using this sb set explicit options and a second mount using * this sb does not set any security options. (The first options * will be used for both mounts) */ @@ -944,10 +944,12 @@ out: return rc; } +/* + * NOTE: the caller is resposible for freeing the memory even if on error. + */ static int selinux_add_opt(int token, const char *s, void **mnt_opts) { struct selinux_mnt_opts *opts = *mnt_opts; - bool is_alloc_opts = false; u32 *dst_sid; int rc; @@ -955,7 +957,7 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts) /* eaten and completely ignored */ return 0; if (!s) - return -ENOMEM; + return -EINVAL; if (!selinux_initialized(&selinux_state)) { pr_warn("SELinux: Unable to set superblock options before the security server is initialized\n"); @@ -967,7 +969,6 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts) if (!opts) return -ENOMEM; *mnt_opts = opts; - is_alloc_opts = true; } switch (token) { @@ -1002,10 +1003,6 @@ static int selinux_add_opt(int token, const char *s, void **mnt_opts) return rc; err: - if (is_alloc_opts) { - kfree(opts); - *mnt_opts = NULL; - } pr_warn(SEL_MOUNT_FAIL_MSG); return -EINVAL; } @@ -1019,7 +1016,7 @@ static int show_sid(struct seq_file *m, u32 sid) rc = security_sid_to_context(&selinux_state, sid, &context, &len); if (!rc) { - bool has_comma = context && strchr(context, ','); + bool has_comma = strchr(context, ','); seq_putc(m, '='); if (has_comma) @@ -2600,8 +2597,9 @@ static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts) } } rc = selinux_add_opt(token, arg, mnt_opts); + kfree(arg); + arg = NULL; if (unlikely(rc)) { - kfree(arg); goto free_opt; } } else { @@ -2792,17 +2790,13 @@ static int selinux_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param) { struct fs_parse_result result; - int opt, rc; + int opt; opt = fs_parse(fc, selinux_fs_parameters, param, &result); if (opt < 0) return opt; - rc = selinux_add_opt(opt, param->string, &fc->security); - if (!rc) - param->string = NULL; - - return rc; + return selinux_add_opt(opt, param->string, &fc->security); } /* inode security operations */ @@ -6795,7 +6789,7 @@ static u32 bpf_map_fmode_to_av(fmode_t fmode) } /* This function will check the file pass through unix socket or binder to see - * if it is a bpf related object. And apply correspinding checks on the bpf + * if it is a bpf related object. And apply corresponding checks on the bpf * object based on the type. The bpf maps and programs, not like other files and * socket, are using a shared anonymous inode inside the kernel as their inode. * So checking that inode cannot identify if the process have privilege to diff --git a/security/selinux/include/audit.h b/security/selinux/include/audit.h index 1cba83d17f41..406bceb90c6c 100644 --- a/security/selinux/include/audit.h +++ b/security/selinux/include/audit.h @@ -18,7 +18,7 @@ /** * selinux_audit_rule_init - alloc/init an selinux audit rule structure. * @field: the field this rule refers to - * @op: the operater the rule uses + * @op: the operator the rule uses * @rulestr: the text "target" of the rule * @rule: pointer to the new rule structure returned via this * diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h index 2b372f98f2d7..5525b94fd266 100644 --- a/security/selinux/include/avc.h +++ b/security/selinux/include/avc.h @@ -53,7 +53,7 @@ struct selinux_audit_data { u32 denied; int result; struct selinux_state *state; -}; +} __randomize_layout; /* * AVC operations diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h index c24d4e1063ea..ffc4e7bad205 100644 --- a/security/selinux/ss/policydb.h +++ b/security/selinux/ss/policydb.h @@ -370,6 +370,8 @@ static inline int put_entry(const void *buf, size_t bytes, int num, struct polic { size_t len = bytes * num; + if (len > fp->len) + return -EINVAL; memcpy(fp->data, buf, len); fp->data += len; fp->len -= len; diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 69b2734311a6..fe5fcf571c56 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -4048,6 +4048,7 @@ int security_read_policy(struct selinux_state *state, int security_read_state_kernel(struct selinux_state *state, void **data, size_t *len) { + int err; struct selinux_policy *policy; policy = rcu_dereference_protected( @@ -4060,5 +4061,11 @@ int security_read_state_kernel(struct selinux_state *state, if (!*data) return -ENOMEM; - return __security_read_policy(policy, *data, len); + err = __security_read_policy(policy, *data, len); + if (err) { + vfree(*data); + *data = NULL; + *len = 0; + } + return err; } diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c index d2186e2757be..585e5e35710b 100644 --- a/security/smack/smack_access.c +++ b/security/smack/smack_access.c @@ -465,12 +465,9 @@ char *smk_parse_smack(const char *string, int len) if (i == 0 || i >= SMK_LONGLABEL) return ERR_PTR(-EINVAL); - smack = kzalloc(i + 1, GFP_NOFS); - if (smack == NULL) + smack = kstrndup(string, i, GFP_NOFS); + if (!smack) return ERR_PTR(-ENOMEM); - - strncpy(smack, string, i); - return smack; } diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 6207762dbdb1..001831458fa2 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -766,13 +766,6 @@ static int smack_set_mnt_opts(struct super_block *sb, if (sp->smk_flags & SMK_SB_INITIALIZED) return 0; - if (inode->i_security == NULL) { - int rc = lsm_inode_alloc(inode); - - if (rc) - return rc; - } - if (!smack_privileged(CAP_MAC_ADMIN)) { /* * Unprivileged mounts don't get to specify Smack values. |