[PATCH] can: isotp: handle wait_event_interruptible() return values

[Oliver Hartkopp <socketcan@hartkopp.net>]

When wait_event_interruptible() has been interrupted by a signal the
tx.state value might not be ISOTP_IDLE. Force the state machines
into idle state to inhibit the timer handlers to continue working.

Cc: stable@vger.kernel.org # >= v5.15
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
---
 net/can/isotp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/can/isotp.c b/net/can/isotp.c
index 0476a506d4a4..d3b39a5b7e74 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1150,10 +1150,13 @@ static int isotp_release(struct socket *sock)
 	net = sock_net(sk);
 
 	/* wait for complete transmission of current pdu */
 	wait_event_interruptible(so->wait, so->tx.state == ISOTP_IDLE);
 
+	/* force state machines to be idle also when a signal occured */
+	so->tx.state = so->rx.state = ISOTP_IDLE;
+
 	spin_lock(&isotp_notifier_lock);
 	while (isotp_busy_notifier == so) {
 		spin_unlock(&isotp_notifier_lock);
 		schedule_timeout_uninterruptible(1);
 		spin_lock(&isotp_notifier_lock);
-- 
2.30.2