syzbot found a bug in audit_buffer_alloc() if nlmsg_new() returns NULL. We need to initialize ab->skb_list before calling audit_buffer_free() which will use both the skb_list spinlock and list pointers. Fixes: eb59d494eebd ("audit: add record for multiple task security contexts") Reported-by: syzbot+bb185b018a51f8d91fd2@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/68b93e3c.a00a0220.eb3d.0000.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Cc: Casey Schaufler Cc: Paul Moore Cc: Eric Paris Cc: audit@vger.kernel.org --- kernel/audit.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/audit.c b/kernel/audit.c index bd7474fd8d2c..707483879648 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -1831,11 +1831,12 @@ static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx, if (!ab) return NULL; + skb_queue_head_init(&ab->skb_list); + ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); if (!ab->skb) goto err; - skb_queue_head_init(&ab->skb_list); skb_queue_tail(&ab->skb_list, ab->skb); if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0)) -- 2.51.0.338.gd7d06c2dae-goog