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: [email protected]
Closes:
https://lore.kernel.org/lkml/[email protected]/T/#u
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Casey Schaufler <[email protected]>
Cc: Paul Moore <[email protected]>
Cc: Eric Paris <[email protected]>
Cc: [email protected]
---
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
