can: isotp: stop timeout monitoring when no first frame was sent
authorOliver Hartkopp <socketcan@hartkopp.net>
Tue, 5 Apr 2022 17:51:12 +0000 (19:51 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 27 Apr 2022 12:38:54 +0000 (14:38 +0200)
commit40ebaf7365b06876db9536978c96e824b932da22
tree670c809bc03f84aa52a4db38c3933b264af77a99
parent652a5405396dd37ea4af66a711c97e66f8192ae0
can: isotp: stop timeout monitoring when no first frame was sent

[ Upstream commit d73497081710c876c3c61444445512989e102152 ]

The first attempt to fix a the 'impossible' WARN_ON_ONCE(1) in
isotp_tx_timer_handler() focussed on the identical CAN IDs created by
the syzbot reproducer and lead to upstream fix/commit 3ea566422cbd
("can: isotp: sanitize CAN ID checks in isotp_bind()"). But this did
not catch the root cause of the wrong tx.state in the tx_timer handler.

In the isotp 'first frame' case a timeout monitoring needs to be started
before the 'first frame' is send. But when this sending failed the timeout
monitoring for this specific frame has to be disabled too.

Otherwise the tx_timer is fired with the 'warn me' tx.state of ISOTP_IDLE.

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/all/20220405175112.2682-1-socketcan@hartkopp.net
Reported-by: syzbot+2339c27f5c66c652843e@syzkaller.appspotmail.com
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net/can/isotp.c