linux-stable/net/can
Michal Sojka c74065da69 can: isotp: isotp_ops: fix poll() to not report false EPOLLOUT events
commit 79e19fa79c upstream.

When using select()/poll()/epoll() with a non-blocking ISOTP socket to
wait for when non-blocking write is possible, a false EPOLLOUT event
is sometimes returned. This can happen at least after sending a
message which must be split to multiple CAN frames.

The reason is that isotp_sendmsg() returns -EAGAIN when tx.state is
not equal to ISOTP_IDLE and this behavior is not reflected in
datagram_poll(), which is used in isotp_ops.

This is fixed by introducing ISOTP-specific poll function, which
suppresses the EPOLLOUT events in that case.

v2: https://lore.kernel.org/all/20230302092812.320643-1-michal.sojka@cvut.cz
v1: https://lore.kernel.org/all/20230224010659.48420-1-michal.sojka@cvut.cz
    https://lore.kernel.org/all/b53a04a2-ba1f-3858-84c1-d3eb3301ae15@hartkopp.net

Signed-off-by: Michal Sojka <michal.sojka@cvut.cz>
Reported-by: Jakub Jira <jirajak2@fel.cvut.cz>
Tested-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: e057dd3fc2 ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/all/20230331125511.372783-1-michal.sojka@cvut.cz
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-13 16:48:25 +02:00
..
j1939 can: j1939: j1939_tp_tx_dat_new(): fix out-of-bounds memory access 2023-04-13 16:48:25 +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: bcm_tx_setup(): fix KMSAN uninit-value in vfs_write 2023-04-05 11:24:56 +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_ops: fix poll() to not report false EPOLLOUT events 2023-04-13 16:48:25 +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
proc.c can: proc: remove unnecessary variables 2021-05-27 09:42:21 +02:00
raw.c net: Remove redundant if statements 2021-08-05 13:27:50 +01:00