apparmor: fix regression in mount mediation when feature set is pinned

When the mount code was refactored for Labels it was not correctly updated to check whether policy supported mediation of the mount class. This causes a regression when the kernel feature set is reported as supporting mount and policy is pinned to a feature set that does not support mount mediation. BugLink: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=882697#41 Fixes: 2ea3ffb ("apparmor: add mount mediation") Reported-by: Fabian Grünbichler <[email protected]> Cc: Stable <[email protected]> Signed-off-by: John Johansen <[email protected]>
chasrmartin · Jan 5, 2018 · 5b9f57c · 5b9f57c
1 parent 30a7acd
commit 5b9f57c
Showing 1 changed file with 11 additions and 1 deletion.
diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c
@@ -329,6 +329,9 @@ static int match_mnt_path_str(struct aa_profile *profile,
 	AA_BUG(!mntpath);
 	AA_BUG(!buffer);
 
+	if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
+		return 0;
+
 	error = aa_path_name(mntpath, path_flags(profile, mntpath), buffer,
 			     &mntpnt, &info, profile->disconnected);
 	if (error)
@@ -380,6 +383,9 @@ static int match_mnt(struct aa_profile *profile, const struct path *path,
 	AA_BUG(!profile);
 	AA_BUG(devpath && !devbuffer);
 
+	if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
+		return 0;
+
 	if (devpath) {
 		error = aa_path_name(devpath, path_flags(profile, devpath),
 				     devbuffer, &devname, &info,
@@ -558,6 +564,9 @@ static int profile_umount(struct aa_profile *profile, struct path *path,
 	AA_BUG(!profile);
 	AA_BUG(!path);
 
+	if (!PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
+		return 0;
+
 	error = aa_path_name(path, path_flags(profile, path), buffer, &name,
 			     &info, profile->disconnected);
 	if (error)
@@ -613,7 +622,8 @@ static struct aa_label *build_pivotroot(struct aa_profile *profile,
 	AA_BUG(!new_path);
 	AA_BUG(!old_path);
 
-	if (profile_unconfined(profile))
+	if (profile_unconfined(profile) ||
+	    !PROFILE_MEDIATES(profile, AA_CLASS_MOUNT))
 		return aa_get_newest_label(&profile->label);
 
 	error = aa_path_name(old_path, path_flags(profile, old_path),