From 6d25e7b47616cb2db43351210929c8f19dc305a3 Mon Sep 17 00:00:00 2001 From: John Johansen Date: Fri, 24 Oct 2025 12:59:51 -0700 Subject: [PATCH] apparmor: fix refcount leak when updating the sk_ctx Currently update_sk_ctx() transfers the plabel reference, unfortunately it is also unconditionally put in the caller. Ideally we would make the caller conditionally put the reference based on whether it was transferred but for now just fix the bug by getting a reference. Fixes: 88fec3526e841 ("apparmor: make sure unix socket labeling is correctly updated.") Signed-off-by: John Johansen --- security/apparmor/af_unix.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/security/apparmor/af_unix.c b/security/apparmor/af_unix.c index 23753cb2096e..834a3b1c2f0a 100644 --- a/security/apparmor/af_unix.c +++ b/security/apparmor/af_unix.c @@ -674,9 +674,11 @@ static void update_sk_ctx(struct sock *sk, struct aa_label *label, old = rcu_dereference_protected(ctx->peer, lockdep_is_held(&unix_sk(sk)->lock)); if (old == plabel) { - rcu_assign_pointer(ctx->peer_lastupdate, plabel); + rcu_assign_pointer(ctx->peer_lastupdate, + aa_get_label(plabel)); } else if (aa_label_is_subset(plabel, old)) { - rcu_assign_pointer(ctx->peer_lastupdate, plabel); + rcu_assign_pointer(ctx->peer_lastupdate, + aa_get_label(plabel)); rcu_assign_pointer(ctx->peer, aa_get_label(plabel)); aa_put_label(old); } /* else race or a subset - don't update */