1 files changed, 39 insertions, 23 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 03fc6a81ae32..4a7374c12d9c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -957,7 +957,8 @@ out_err:
         return rc;
 }
 
-void selinux_write_opts(struct seq_file *m, struct security_mnt_opts *opts)
+static void selinux_write_opts(struct seq_file *m,
+                               struct security_mnt_opts *opts)
 {
         int i;
         char *prefix;
@@ -1290,7 +1291,7 @@ static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dent
                 /* Default to the fs superblock SID. */
                 isec->sid = sbsec->sid;
 
-                if (sbsec->proc) {
+                if (sbsec->proc && !S_ISLNK(inode->i_mode)) {
                         struct proc_inode *proci = PROC_I(inode);
                         if (proci->pde) {
                                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
@@ -3548,38 +3549,44 @@ out:
 #endif /* IPV6 */
 
 static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
-                             char **addrp, int src, u8 *proto)
+                             char **_addrp, int src, u8 *proto)
 {
-        int ret = 0;
+        char *addrp;
+        int ret;
 
         switch (ad->u.net.family) {
         case PF_INET:
                 ret = selinux_parse_skb_ipv4(skb, ad, proto);
-                if (ret || !addrp)
-                        break;
-                *addrp = (char *)(src ? &ad->u.net.v4info.saddr :
-                                        &ad->u.net.v4info.daddr);
-                break;
+                if (ret)
+                        goto parse_error;
+                addrp = (char *)(src ? &ad->u.net.v4info.saddr :
+                                       &ad->u.net.v4info.daddr);
+                goto okay;
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
         case PF_INET6:
                 ret = selinux_parse_skb_ipv6(skb, ad, proto);
-                if (ret || !addrp)
-                        break;
-                *addrp = (char *)(src ? &ad->u.net.v6info.saddr :
-                                        &ad->u.net.v6info.daddr);
-                break;
+                if (ret)
+                        goto parse_error;
+                addrp = (char *)(src ? &ad->u.net.v6info.saddr :
+                                       &ad->u.net.v6info.daddr);
+                goto okay;
 #endif  /* IPV6 */
         default:
-                break;
+                addrp = NULL;
+                goto okay;
         }
 
-        if (unlikely(ret))
-                printk(KERN_WARNING
-                       "SELinux: failure in selinux_parse_skb(),"
-                       " unable to parse packet\n");
-
+parse_error:
+        printk(KERN_WARNING
+               "SELinux: failure in selinux_parse_skb(),"
+               " unable to parse packet\n");
         return ret;
+
+okay:
+        if (_addrp)
+                *_addrp = addrp;
+        return 0;
 }
 
 /**
@@ -5219,8 +5226,12 @@ static int selinux_setprocattr(struct task_struct *p,
 
                 if (sid == 0)
                         return -EINVAL;
-
-                /* Only allow single threaded processes to change context */
+                /*
+                 * SELinux allows to change context in the following case only.
+                 *  - Single threaded processes.
+                 *  - Multi threaded processes intend to change its context into
+                 *    more restricted domain (defined by TYPEBOUNDS statement).
+                 */
                 if (atomic_read(&p->mm->mm_users) != 1) {
                         struct task_struct *g, *t;
                         struct mm_struct *mm = p->mm;
@@ -5228,11 +5239,16 @@ static int selinux_setprocattr(struct task_struct *p,
                         do_each_thread(g, t) {
                                 if (t->mm == mm && t != p) {
                                         read_unlock(&tasklist_lock);
-                                        return -EPERM;
+                                        error = security_bounded_transition(tsec->sid, sid);
+                                        if (!error)
+                                                goto boundary_ok;
+
+                                        return error;
                                 }
                         } while_each_thread(g, t);
                         read_unlock(&tasklist_lock);
                 }
+boundary_ok:
 
                 /* Check permissions for the transition. */
                 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,