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| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2021-06-18 19:37:13 +0200 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2021-06-19 23:54:00 +0200 |
| commit | 14a4696bc3118ba49da28f79280e1d55603aa737 (patch) | |
| tree | 0d45c20e707975956c63ccb4608d16b5fe5f291e | |
| parent | fb8696ab14adadb2e3f6c17c18ed26b3ecd96691 (diff) | |
| download | lwn-14a4696bc3118ba49da28f79280e1d55603aa737.tar.gz lwn-14a4696bc3118ba49da28f79280e1d55603aa737.zip | |
can: isotp: isotp_release(): omit unintended hrtimer restart on socket release
When closing the isotp socket, the potentially running hrtimers are
canceled before removing the subscription for CAN identifiers via
can_rx_unregister().
This may lead to an unintended (re)start of a hrtimer in
isotp_rcv_cf() and isotp_rcv_fc() in the case that a CAN frame is
received by isotp_rcv() while the subscription removal is processed.
However, isotp_rcv() is called under RCU protection, so after calling
can_rx_unregister, we may call synchronize_rcu in order to wait for
any RCU read-side critical sections to finish. This prevents the
reception of CAN frames after hrtimer_cancel() and therefore the
unintended (re)start of the hrtimers.
Link: https://lore.kernel.org/r/20210618173713.2296-1-socketcan@hartkopp.net
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
| -rw-r--r-- | net/can/isotp.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/net/can/isotp.c b/net/can/isotp.c index be6183f8ca11..234cc4ad179a 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -1028,9 +1028,6 @@ static int isotp_release(struct socket *sock) lock_sock(sk); - hrtimer_cancel(&so->txtimer); - hrtimer_cancel(&so->rxtimer); - /* remove current filters & unregister */ if (so->bound && (!(so->opt.flags & CAN_ISOTP_SF_BROADCAST))) { if (so->ifindex) { @@ -1042,10 +1039,14 @@ static int isotp_release(struct socket *sock) SINGLE_MASK(so->rxid), isotp_rcv, sk); dev_put(dev); + synchronize_rcu(); } } } + hrtimer_cancel(&so->txtimer); + hrtimer_cancel(&so->rxtimer); + so->ifindex = 0; so->bound = 0; |