apparmor: fix lockdep warning when removing a namespace
authorJohn Johansen <john.johansen@canonical.com>
Tue, 6 Sep 2022 10:39:55 +0000 (03:39 -0700)
committerJohn Johansen <john.johansen@canonical.com>
Mon, 3 Oct 2022 21:49:02 +0000 (14:49 -0700)
Fix the following lockdep warning

[ 1119.158984] ============================================
[ 1119.158988] WARNING: possible recursive locking detected
[ 1119.158996] 6.0.0-rc1+ #257 Tainted: G            E    N
[ 1119.158999] --------------------------------------------
[ 1119.159001] bash/80100 is trying to acquire lock:
[ 1119.159007] ffff88803e79b4a0 (&ns->lock/1){+.+.}-{4:4}, at: destroy_ns.part.0+0x43/0x140
[ 1119.159028]
               but task is already holding lock:
[ 1119.159030] ffff8881009764a0 (&ns->lock/1){+.+.}-{4:4}, at: aa_remove_profiles+0x3f0/0x640
[ 1119.159040]
               other info that might help us debug this:
[ 1119.159042]  Possible unsafe locking scenario:

[ 1119.159043]        CPU0
[ 1119.159045]        ----
[ 1119.159047]   lock(&ns->lock/1);
[ 1119.159051]   lock(&ns->lock/1);
[ 1119.159055]
                *** DEADLOCK ***

Which is caused by an incorrect lockdep nesting notation

Fixes: feb3c766a3ab ("apparmor: fix possible recursive lock warning in __aa_create_ns")
Signed-off-by: John Johansen <john.johansen@canonical.com>
security/apparmor/policy.c

index 499c020..fbdfcef 100644 (file)
@@ -1170,7 +1170,7 @@ ssize_t aa_remove_profiles(struct aa_ns *policy_ns, struct aa_label *subj,
 
        if (!name) {
                /* remove namespace - can only happen if fqname[0] == ':' */
-               mutex_lock_nested(&ns->parent->lock, ns->level);
+               mutex_lock_nested(&ns->parent->lock, ns->parent->level);
                __aa_bump_ns_revision(ns);
                __aa_remove_ns(ns);
                mutex_unlock(&ns->parent->lock);