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Diffstat (limited to 'security/selinux/hooks.c')
-rw-r--r--security/selinux/hooks.c39
1 files changed, 35 insertions, 4 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 7171a957b933..feb2f42c5a07 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -751,7 +751,37 @@ out_double_mount:
goto out;
}
-static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
+static int selinux_cmp_sb_context(const struct super_block *oldsb,
+ const struct super_block *newsb)
+{
+ struct superblock_security_struct *old = oldsb->s_security;
+ struct superblock_security_struct *new = newsb->s_security;
+ char oldflags = old->flags & SE_MNTMASK;
+ char newflags = new->flags & SE_MNTMASK;
+
+ if (oldflags != newflags)
+ goto mismatch;
+ if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid)
+ goto mismatch;
+ if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid)
+ goto mismatch;
+ if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid)
+ goto mismatch;
+ if (oldflags & ROOTCONTEXT_MNT) {
+ struct inode_security_struct *oldroot = oldsb->s_root->d_inode->i_security;
+ struct inode_security_struct *newroot = newsb->s_root->d_inode->i_security;
+ if (oldroot->sid != newroot->sid)
+ goto mismatch;
+ }
+ return 0;
+mismatch:
+ printk(KERN_WARNING "SELinux: mount invalid. Same superblock, "
+ "different security settings for (dev %s, "
+ "type %s)\n", newsb->s_id, newsb->s_type->name);
+ return -EBUSY;
+}
+
+static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
struct super_block *newsb)
{
const struct superblock_security_struct *oldsbsec = oldsb->s_security;
@@ -766,14 +796,14 @@ static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
* mount options. thus we can safely deal with this superblock later
*/
if (!ss_initialized)
- return;
+ return 0;
/* how can we clone if the old one wasn't set up?? */
BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
- /* if fs is reusing a sb, just let its options stand... */
+ /* if fs is reusing a sb, make sure that the contexts match */
if (newsbsec->flags & SE_SBINITIALIZED)
- return;
+ return selinux_cmp_sb_context(oldsb, newsb);
mutex_lock(&newsbsec->lock);
@@ -806,6 +836,7 @@ static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
sb_finish_set_opts(newsb);
mutex_unlock(&newsbsec->lock);
+ return 0;
}
static int selinux_parse_opts_str(char *options,