[PATCH 5.15 359/731] apparmor: fix lockdep warning when removing a namespace

Greg Kroah-Hartman
2022-12-28T15:14:49Z

From: John Johansen <john.johansen@canonical.com>

[ Upstream commit 9c4557efc558a68e4cd973490fd936d6e3414db8 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
security/apparmor/policy.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 4c010c9a6af1..fcf22577f606 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -1125,7 +1125,7 @@ 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);
--
2.35.1