can: j1939: j1939_session_destroy(): fix memory leak of skbs

We need to drop skb references taken in j1939_session_skb_queue() when
destroying a session in j1939_session_destroy(). Otherwise those skbs
would be lost.

Link to Syzkaller info and repro: https://forge.ispras.ru/issues/11743.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

V1: https://lore.kernel.org/all/20220708175949.539064-1-pchelkin@ispras.ru

Fixes: 9d71dd0c70 ("can: add support of SAE J1939 protocol")
Suggested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://lore.kernel.org/all/20220805150216.66313-1-pchelkin@ispras.ru
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Fedor Pchelkin 2022-08-05 18:02:16 +03:00 committed by Marc Kleine-Budde
parent 8ef49f7f82
commit 8c21c54a53

View File

@ -260,6 +260,8 @@ static void __j1939_session_drop(struct j1939_session *session)
static void j1939_session_destroy(struct j1939_session *session)
{
struct sk_buff *skb;
if (session->transmission) {
if (session->err)
j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ABORT);
@ -274,7 +276,11 @@ static void j1939_session_destroy(struct j1939_session *session)
WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry));
WARN_ON_ONCE(!list_empty(&session->active_session_list_entry));
skb_queue_purge(&session->skb_queue);
while ((skb = skb_dequeue(&session->skb_queue)) != NULL) {
/* drop ref taken in j1939_session_skb_queue() */
skb_unref(skb);
kfree_skb(skb);
}
__j1939_session_drop(session);
j1939_priv_put(session->priv);
kfree(session);