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-rw-r--r--security/smack/smack_lsm.c266
1 files changed, 179 insertions, 87 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index b9c5e149903b..7db62b48eb42 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -5,12 +5,13 @@
*
* Authors:
* Casey Schaufler <casey@schaufler-ca.com>
- * Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com>
+ * Jarkko Sakkinen <jarkko.sakkinen@intel.com>
*
* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
* Paul Moore <paul@paul-moore.com>
* Copyright (C) 2010 Nokia Corporation
+ * Copyright (C) 2011 Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2,
@@ -34,6 +35,7 @@
#include <linux/audit.h>
#include <linux/magic.h>
#include <linux/dcache.h>
+#include <linux/personality.h>
#include "smack.h"
#define task_security(task) (task_cred_xxx((task), security))
@@ -441,11 +443,17 @@ static int smack_sb_umount(struct vfsmount *mnt, int flags)
* BPRM hooks
*/
+/**
+ * smack_bprm_set_creds - set creds for exec
+ * @bprm: the exec information
+ *
+ * Returns 0 if it gets a blob, -ENOMEM otherwise
+ */
static int smack_bprm_set_creds(struct linux_binprm *bprm)
{
- struct task_smack *tsp = bprm->cred->security;
+ struct inode *inode = bprm->file->f_path.dentry->d_inode;
+ struct task_smack *bsp = bprm->cred->security;
struct inode_smack *isp;
- struct dentry *dp;
int rc;
rc = cap_bprm_set_creds(bprm);
@@ -455,20 +463,48 @@ static int smack_bprm_set_creds(struct linux_binprm *bprm)
if (bprm->cred_prepared)
return 0;
- if (bprm->file == NULL || bprm->file->f_dentry == NULL)
+ isp = inode->i_security;
+ if (isp->smk_task == NULL || isp->smk_task == bsp->smk_task)
return 0;
- dp = bprm->file->f_dentry;
+ if (bprm->unsafe)
+ return -EPERM;
- if (dp->d_inode == NULL)
- return 0;
+ bsp->smk_task = isp->smk_task;
+ bprm->per_clear |= PER_CLEAR_ON_SETID;
- isp = dp->d_inode->i_security;
+ return 0;
+}
- if (isp->smk_task != NULL)
- tsp->smk_task = isp->smk_task;
+/**
+ * smack_bprm_committing_creds - Prepare to install the new credentials
+ * from bprm.
+ *
+ * @bprm: binprm for exec
+ */
+static void smack_bprm_committing_creds(struct linux_binprm *bprm)
+{
+ struct task_smack *bsp = bprm->cred->security;
- return 0;
+ if (bsp->smk_task != bsp->smk_forked)
+ current->pdeath_signal = 0;
+}
+
+/**
+ * smack_bprm_secureexec - Return the decision to use secureexec.
+ * @bprm: binprm for exec
+ *
+ * Returns 0 on success.
+ */
+static int smack_bprm_secureexec(struct linux_binprm *bprm)
+{
+ struct task_smack *tsp = current_security();
+ int ret = cap_bprm_secureexec(bprm);
+
+ if (!ret && (tsp->smk_task != tsp->smk_forked))
+ ret = 1;
+
+ return ret;
}
/*
@@ -516,6 +552,8 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
const struct qstr *qstr, char **name,
void **value, size_t *len)
{
+ struct smack_known *skp;
+ char *csp = smk_of_current();
char *isp = smk_of_inode(inode);
char *dsp = smk_of_inode(dir);
int may;
@@ -527,8 +565,9 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
}
if (value) {
+ skp = smk_find_entry(csp);
rcu_read_lock();
- may = smk_access_entry(smk_of_current(), dsp, &smack_rule_list);
+ may = smk_access_entry(csp, dsp, &skp->smk_rules);
rcu_read_unlock();
/*
@@ -841,7 +880,7 @@ static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
return;
}
-/*
+/**
* smack_inode_getxattr - Smack check on getxattr
* @dentry: the object
* @name: unused
@@ -858,7 +897,7 @@ static int smack_inode_getxattr(struct dentry *dentry, const char *name)
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ, &ad);
}
-/*
+/**
* smack_inode_removexattr - Smack check on removexattr
* @dentry: the object
* @name: name of the attribute
@@ -1088,36 +1127,31 @@ static int smack_file_lock(struct file *file, unsigned int cmd)
* @cmd: what action to check
* @arg: unused
*
+ * Generally these operations are harmless.
+ * File locking operations present an obvious mechanism
+ * for passing information, so they require write access.
+ *
* Returns 0 if current has access, error code otherwise
*/
static int smack_file_fcntl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct smk_audit_info ad;
- int rc;
+ int rc = 0;
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
- smk_ad_setfield_u_fs_path(&ad, file->f_path);
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, &ad);
- break;
- case F_SETFD:
- case F_SETFL:
case F_SETLK:
case F_SETLKW:
case F_SETOWN:
case F_SETSIG:
+ smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_PATH);
+ smk_ad_setfield_u_fs_path(&ad, file->f_path);
rc = smk_curacc(file->f_security, MAY_WRITE, &ad);
break;
default:
- rc = smk_curacc(file->f_security, MAY_READWRITE, &ad);
+ break;
}
return rc;
@@ -1138,6 +1172,7 @@ static int smack_file_mmap(struct file *file,
unsigned long flags, unsigned long addr,
unsigned long addr_only)
{
+ struct smack_known *skp;
struct smack_rule *srp;
struct task_smack *tsp;
char *sp;
@@ -1170,6 +1205,7 @@ static int smack_file_mmap(struct file *file,
tsp = current_security();
sp = smk_of_current();
+ skp = smk_find_entry(sp);
rc = 0;
rcu_read_lock();
@@ -1177,15 +1213,8 @@ static int smack_file_mmap(struct file *file,
* For each Smack rule associated with the subject
* label verify that the SMACK64MMAP also has access
* to that rule's object label.
- *
- * Because neither of the labels comes
- * from the networking code it is sufficient
- * to compare pointers.
*/
- list_for_each_entry_rcu(srp, &smack_rule_list, list) {
- if (srp->smk_subject != sp)
- continue;
-
+ list_for_each_entry_rcu(srp, &skp->smk_rules, list) {
osmack = srp->smk_object;
/*
* Matching labels always allows access.
@@ -1214,7 +1243,8 @@ static int smack_file_mmap(struct file *file,
* If there isn't one a SMACK64MMAP subject
* can't have as much access as current.
*/
- mmay = smk_access_entry(msmack, osmack, &smack_rule_list);
+ skp = smk_find_entry(msmack);
+ mmay = smk_access_entry(msmack, osmack, &skp->smk_rules);
if (mmay == -ENOENT) {
rc = -EACCES;
break;
@@ -1315,6 +1345,24 @@ static int smack_file_receive(struct file *file)
return smk_curacc(file->f_security, may, &ad);
}
+/**
+ * smack_dentry_open - Smack dentry open processing
+ * @file: the object
+ * @cred: unused
+ *
+ * Set the security blob in the file structure.
+ *
+ * Returns 0
+ */
+static int smack_dentry_open(struct file *file, const struct cred *cred)
+{
+ struct inode_smack *isp = file->f_path.dentry->d_inode->i_security;
+
+ file->f_security = isp->smk_inode;
+
+ return 0;
+}
+
/*
* Task hooks
*/
@@ -1455,15 +1503,17 @@ static int smack_kernel_create_files_as(struct cred *new,
/**
* smk_curacc_on_task - helper to log task related access
* @p: the task object
- * @access : the access requested
+ * @access: the access requested
+ * @caller: name of the calling function for audit
*
* Return 0 if access is permitted
*/
-static int smk_curacc_on_task(struct task_struct *p, int access)
+static int smk_curacc_on_task(struct task_struct *p, int access,
+ const char *caller)
{
struct smk_audit_info ad;
- smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_TASK);
+ smk_ad_init(&ad, caller, LSM_AUDIT_DATA_TASK);
smk_ad_setfield_u_tsk(&ad, p);
return smk_curacc(smk_of_task(task_security(p)), access, &ad);
}
@@ -1477,7 +1527,7 @@ static int smk_curacc_on_task(struct task_struct *p, int access)
*/
static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
{
- return smk_curacc_on_task(p, MAY_WRITE);
+ return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
@@ -1488,7 +1538,7 @@ static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
*/
static int smack_task_getpgid(struct task_struct *p)
{
- return smk_curacc_on_task(p, MAY_READ);
+ return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
@@ -1499,7 +1549,7 @@ static int smack_task_getpgid(struct task_struct *p)
*/
static int smack_task_getsid(struct task_struct *p)
{
- return smk_curacc_on_task(p, MAY_READ);
+ return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
@@ -1527,7 +1577,7 @@ static int smack_task_setnice(struct task_struct *p, int nice)
rc = cap_task_setnice(p, nice);
if (rc == 0)
- rc = smk_curacc_on_task(p, MAY_WRITE);
+ rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
return rc;
}
@@ -1544,7 +1594,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio)
rc = cap_task_setioprio(p, ioprio);
if (rc == 0)
- rc = smk_curacc_on_task(p, MAY_WRITE);
+ rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
return rc;
}
@@ -1556,7 +1606,7 @@ static int smack_task_setioprio(struct task_struct *p, int ioprio)
*/
static int smack_task_getioprio(struct task_struct *p)
{
- return smk_curacc_on_task(p, MAY_READ);
+ return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
@@ -1573,7 +1623,7 @@ static int smack_task_setscheduler(struct task_struct *p)
rc = cap_task_setscheduler(p);
if (rc == 0)
- rc = smk_curacc_on_task(p, MAY_WRITE);
+ rc = smk_curacc_on_task(p, MAY_WRITE, __func__);
return rc;
}
@@ -1585,7 +1635,7 @@ static int smack_task_setscheduler(struct task_struct *p)
*/
static int smack_task_getscheduler(struct task_struct *p)
{
- return smk_curacc_on_task(p, MAY_READ);
+ return smk_curacc_on_task(p, MAY_READ, __func__);
}
/**
@@ -1596,7 +1646,7 @@ static int smack_task_getscheduler(struct task_struct *p)
*/
static int smack_task_movememory(struct task_struct *p)
{
- return smk_curacc_on_task(p, MAY_WRITE);
+ return smk_curacc_on_task(p, MAY_WRITE, __func__);
}
/**
@@ -1711,7 +1761,7 @@ static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
ssp->smk_in = csp;
ssp->smk_out = csp;
- ssp->smk_packet[0] = '\0';
+ ssp->smk_packet = NULL;
sk->sk_security = ssp;
@@ -2753,6 +2803,7 @@ static int smack_unix_stream_connect(struct sock *sock,
{
struct socket_smack *ssp = sock->sk_security;
struct socket_smack *osp = other->sk_security;
+ struct socket_smack *nsp = newsk->sk_security;
struct smk_audit_info ad;
int rc = 0;
@@ -2762,6 +2813,14 @@ static int smack_unix_stream_connect(struct sock *sock,
if (!capable(CAP_MAC_OVERRIDE))
rc = smk_access(ssp->smk_out, osp->smk_in, MAY_WRITE, &ad);
+ /*
+ * Cross reference the peer labels for SO_PEERSEC.
+ */
+ if (rc == 0) {
+ nsp->smk_packet = ssp->smk_out;
+ ssp->smk_packet = osp->smk_out;
+ }
+
return rc;
}
@@ -2813,16 +2872,17 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
return smack_netlabel_send(sock->sk, sip);
}
-
/**
* smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack
* @sap: netlabel secattr
- * @sip: where to put the result
+ * @ssp: socket security information
*
- * Copies a smack label into sip
+ * Returns a pointer to a Smack label found on the label list.
*/
-static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
+static char *smack_from_secattr(struct netlbl_lsm_secattr *sap,
+ struct socket_smack *ssp)
{
+ struct smack_known *skp;
char smack[SMK_LABELLEN];
char *sp;
int pcat;
@@ -2852,15 +2912,43 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
* we are already done. WeeHee.
*/
if (sap->attr.mls.lvl == smack_cipso_direct) {
- memcpy(sip, smack, SMK_MAXLEN);
- return;
+ /*
+ * The label sent is usually on the label list.
+ *
+ * If it is not we may still want to allow the
+ * delivery.
+ *
+ * If the recipient is accepting all packets
+ * because it is using the star ("*") label
+ * for SMACK64IPIN provide the web ("@") label
+ * so that a directed response will succeed.
+ * This is not very correct from a MAC point
+ * of view, but gets around the problem that
+ * locking prevents adding the newly discovered
+ * label to the list.
+ * The case where the recipient is not using
+ * the star label should obviously fail.
+ * The easy way to do this is to provide the
+ * star label as the subject label.
+ */
+ skp = smk_find_entry(smack);
+ if (skp != NULL)
+ return skp->smk_known;
+ if (ssp != NULL &&
+ ssp->smk_in == smack_known_star.smk_known)
+ return smack_known_web.smk_known;
+ return smack_known_star.smk_known;
}
/*
* Look it up in the supplied table if it is not
* a direct mapping.
*/
- smack_from_cipso(sap->attr.mls.lvl, smack, sip);
- return;
+ sp = smack_from_cipso(sap->attr.mls.lvl, smack);
+ if (sp != NULL)
+ return sp;
+ if (ssp != NULL && ssp->smk_in == smack_known_star.smk_known)
+ return smack_known_web.smk_known;
+ return smack_known_star.smk_known;
}
if ((sap->flags & NETLBL_SECATTR_SECID) != 0) {
/*
@@ -2875,16 +2963,14 @@ static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
* secid is from a fallback.
*/
BUG_ON(sp == NULL);
- strncpy(sip, sp, SMK_MAXLEN);
- return;
+ return sp;
}
/*
* Without guidance regarding the smack value
* for the packet fall back on the network
* ambient value.
*/
- strncpy(sip, smack_net_ambient, SMK_MAXLEN);
- return;
+ return smack_net_ambient;
}
/**
@@ -2898,7 +2984,6 @@ 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];
char *csp;
int rc;
struct smk_audit_info ad;
@@ -2911,10 +2996,9 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
- if (rc == 0) {
- smack_from_secattr(&secattr, smack);
- csp = smack;
- } else
+ if (rc == 0)
+ csp = smack_from_secattr(&secattr, ssp);
+ else
csp = smack_net_ambient;
netlbl_secattr_destroy(&secattr);
@@ -2951,15 +3035,19 @@ static int smack_socket_getpeersec_stream(struct socket *sock,
int __user *optlen, unsigned len)
{
struct socket_smack *ssp;
- int slen;
+ char *rcp = "";
+ int slen = 1;
int rc = 0;
ssp = sock->sk->sk_security;
- slen = strlen(ssp->smk_packet) + 1;
+ if (ssp->smk_packet != NULL) {
+ rcp = ssp->smk_packet;
+ slen = strlen(rcp) + 1;
+ }
if (slen > len)
rc = -ERANGE;
- else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
+ else if (copy_to_user(optval, rcp, slen) != 0)
rc = -EFAULT;
if (put_user(slen, optlen) != 0)
@@ -2982,8 +3070,8 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
{
struct netlbl_lsm_secattr secattr;
- struct socket_smack *sp;
- char smack[SMK_LABELLEN];
+ struct socket_smack *ssp = NULL;
+ char *sp;
int family = PF_UNSPEC;
u32 s = 0; /* 0 is the invalid secid */
int rc;
@@ -2998,17 +3086,19 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
family = sock->sk->sk_family;
if (family == PF_UNIX) {
- sp = sock->sk->sk_security;
- s = smack_to_secid(sp->smk_out);
+ ssp = sock->sk->sk_security;
+ s = smack_to_secid(ssp->smk_out);
} else if (family == PF_INET || family == PF_INET6) {
/*
* Translate what netlabel gave us.
*/
+ if (sock != NULL && sock->sk != NULL)
+ ssp = sock->sk->sk_security;
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, family, &secattr);
if (rc == 0) {
- smack_from_secattr(&secattr, smack);
- s = smack_to_secid(smack);
+ sp = smack_from_secattr(&secattr, ssp);
+ s = smack_to_secid(sp);
}
netlbl_secattr_destroy(&secattr);
}
@@ -3056,7 +3146,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
struct netlbl_lsm_secattr secattr;
struct sockaddr_in addr;
struct iphdr *hdr;
- char smack[SMK_LABELLEN];
+ char *sp;
int rc;
struct smk_audit_info ad;
@@ -3067,9 +3157,9 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, family, &secattr);
if (rc == 0)
- smack_from_secattr(&secattr, smack);
+ sp = smack_from_secattr(&secattr, ssp);
else
- strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
+ sp = smack_known_huh.smk_known;
netlbl_secattr_destroy(&secattr);
#ifdef CONFIG_AUDIT
@@ -3082,7 +3172,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
* Receiving a packet requires that the other end be able to write
* here. Read access is not required.
*/
- rc = smk_access(smack, ssp->smk_in, MAY_WRITE, &ad);
+ rc = smk_access(sp, ssp->smk_in, MAY_WRITE, &ad);
if (rc != 0)
return rc;
@@ -3090,7 +3180,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
* Save the peer's label in the request_sock so we can later setup
* smk_packet in the child socket so that SO_PEERCRED can report it.
*/
- req->peer_secid = smack_to_secid(smack);
+ req->peer_secid = smack_to_secid(sp);
/*
* We need to decide if we want to label the incoming connection here
@@ -3103,7 +3193,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
if (smack_host_label(&addr) == NULL) {
rcu_read_unlock();
netlbl_secattr_init(&secattr);
- smack_to_secattr(smack, &secattr);
+ smack_to_secattr(sp, &secattr);
rc = netlbl_req_setattr(req, &secattr);
netlbl_secattr_destroy(&secattr);
} else {
@@ -3125,13 +3215,11 @@ static void smack_inet_csk_clone(struct sock *sk,
const struct request_sock *req)
{
struct socket_smack *ssp = sk->sk_security;
- char *smack;
- if (req->peer_secid != 0) {
- smack = smack_from_secid(req->peer_secid);
- strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
- } else
- ssp->smk_packet[0] = '\0';
+ if (req->peer_secid != 0)
+ ssp->smk_packet = smack_from_secid(req->peer_secid);
+ else
+ ssp->smk_packet = NULL;
}
/*
@@ -3409,6 +3497,8 @@ struct security_operations smack_ops = {
.sb_umount = smack_sb_umount,
.bprm_set_creds = smack_bprm_set_creds,
+ .bprm_committing_creds = smack_bprm_committing_creds,
+ .bprm_secureexec = smack_bprm_secureexec,
.inode_alloc_security = smack_inode_alloc_security,
.inode_free_security = smack_inode_free_security,
@@ -3440,6 +3530,8 @@ struct security_operations smack_ops = {
.file_send_sigiotask = smack_file_send_sigiotask,
.file_receive = smack_file_receive,
+ .dentry_open = smack_dentry_open,
+
.cred_alloc_blank = smack_cred_alloc_blank,
.cred_free = smack_cred_free,
.cred_prepare = smack_cred_prepare,