media: imon: Fix race getting ictx->lock

[ Upstream commit 24147897507cd3a7d63745d1518a638bf4132238 ]

Lets fix a race between mutex_is_lock() and mutex_lock().

<-mutex is not locked
if (!mutex_is_locked(&ictx->lock)) {
	unlock = true; <- mutex is locked externaly
	mutex_lock(&ictx->lock);
}

Let's use mutex_trylock() that does mutex_is_lock() and mutex_lock()
atomically.

Fix the following cocci warning:
drivers/media/rc/imon.c:1167:1-7: preceding lock on line 1153

Fixes: 23ef710e1a ("[media] imon: add conditional locking in change_protocol")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Ricardo Ribalda 2024-05-06 21:10:27 +00:00 committed by Greg Kroah-Hartman
parent bcc963f591
commit f3968b3d3c

View File

@ -1153,10 +1153,7 @@ static int imon_ir_change_protocol(struct rc_dev *rc, u64 *rc_proto)
memcpy(ictx->usb_tx_buf, &ir_proto_packet, sizeof(ir_proto_packet));
if (!mutex_is_locked(&ictx->lock)) {
unlock = true;
mutex_lock(&ictx->lock);
}
unlock = mutex_trylock(&ictx->lock);
retval = send_packet(ictx);
if (retval)