From: Fedor Pchelkin Date: Fri, 5 Aug 2022 15:02:16 +0000 (+0300) Subject: can: j1939: j1939_session_destroy(): fix memory leak of skbs X-Git-Tag: v5.15.73~964 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=98dc8fb08299ab49e0b9c08daedadd2f4de1a2f2;p=platform%2Fkernel%2Flinux-rpi.git can: j1939: j1939_session_destroy(): fix memory leak of skbs commit 8c21c54a53ab21842f5050fa090f26b03c0313d6 upstream. 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: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Suggested-by: Oleksij Rempel Signed-off-by: Fedor Pchelkin Signed-off-by: Alexey Khoroshilov Acked-by: Oleksij Rempel Link: https://lore.kernel.org/all/20220805150216.66313-1-pchelkin@ispras.ru Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index 307ee11..d7d86c9 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -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);