This is a note to let you know that I've just added the patch titled
can: j1939: j1939_session_new(): fix skb reference counting
to the 6.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
can-j1939-j1939_session_new-fix-skb-reference-counti.patch
and it can be found in the queue-6.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d7500b2671038638c8f18b18ac873eb62b59135b
Author: Dmitry Antipov <dmantipov@xxxxxxxxx>
Date: Tue Nov 5 12:48:23 2024 +0300
can: j1939: j1939_session_new(): fix skb reference counting
[ Upstream commit a8c695005bfe6569acd73d777ca298ddddd66105 ]
Since j1939_session_skb_queue() does an extra skb_get() for each new
skb, do the same for the initial one in j1939_session_new() to avoid
refcount underflow.
Reported-by: syzbot+d4e8dc385d9258220c31@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=d4e8dc385d9258220c31
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Dmitry Antipov <dmantipov@xxxxxxxxx>
Tested-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Acked-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Link: https://patch.msgid.link/20241105094823.2403806-1-dmantipov@xxxxxxxxx
[mkl: clean up commit message]
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 319f47df33300..95f7a7e65a73f 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1505,7 +1505,7 @@ static struct j1939_session *j1939_session_new(struct j1939_priv *priv,
session->state = J1939_SESSION_NEW;
skb_queue_head_init(&session->skb_queue);
- skb_queue_tail(&session->skb_queue, skb);
+ skb_queue_tail(&session->skb_queue, skb_get(skb));
skcb = j1939_skb_to_cb(skb);
memcpy(&session->skcb, skcb, sizeof(session->skcb));
