Oliver Hartkopp 9015169f00 can: isotp: isotp_sendmsg(): fix TX state detection and wait behavior ... From: Lukas Magel <lukas.magel@posteo.net> [ Upstream commit d9c2ba65e6 ] With patch [1], isotp_poll was updated to also queue the poller in the so->wait queue, which is used for send state changes. Since the queue now also contains polling tasks that are not interested in sending, the queue fill state can no longer be used as an indication of send readiness. As a consequence, nonblocking writes can lead to a race and lock-up of the socket if there is a second task polling the socket in parallel. With this patch, isotp_sendmsg does not consult wq_has_sleepers but instead tries to atomically set so->tx.state and waits on so->wait if it is unable to do so. This behavior is in alignment with isotp_poll, which also checks so->tx.state to determine send readiness. V2: - Revert direct exit to goto err_event_drop [1] https://lore.kernel.org/all/20230331125511.372783-1-michal.sojka@cvut.cz Reported-by: Maxime Jayat <maxime.jayat@mobile-devices.fr> Closes: https://lore.kernel.org/linux-can/11328958-453f-447f-9af8-3b5824dfb041@munic.io/ Signed-off-by: Lukas Magel <lukas.magel@posteo.net> Reviewed-by: Oliver Hartkopp <socketcan@hartkopp.net> Fixes: 79e19fa79c ("can: isotp: isotp_ops: fix poll() to not report false EPOLLOUT events") Link: https://github.com/pylessard/python-udsoncan/issues/178#issuecomment-1743786590 Link: https://lore.kernel.org/all/20230827092205.7908-1-lukas.magel@posteo.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-11-08 17:26:49 +01:00
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j1939	can: j1939: avoid possible use-after-free when j1939_can_rx_register fails	2023-06-14 11:13:06 +02:00
Kconfig	net: remove redundant 'depends on NET'	2021-01-27 17:04:12 -08:00
Makefile	can: add ISO 15765-2:2016 transport protocol	2020-10-07 23:18:33 +02:00
af_can.c	can: af_can: fix NULL pointer dereference in can_rcv_filter	2022-12-14 11:37:22 +01:00
af_can.h	can: introduce CAN midlayer private and allocate it automatically	2019-09-04 13:29:14 +02:00
bcm.c	can: bcm: Fix UAF in bcm_proc_show()	2023-07-27 08:46:55 +02:00
gw.c	can: gw: synchronize rcu operations before removing gw job entry	2021-06-19 23:53:43 +02:00
isotp.c	can: isotp: isotp_sendmsg(): fix TX state detection and wait behavior	2023-11-08 17:26:49 +01:00
proc.c	can: proc: remove unnecessary variables	2021-05-27 09:42:21 +02:00
raw.c	can: raw: add missing refcount for memory leak fix	2023-08-30 16:18:20 +02:00