media: cec: forgot to cancel delayed work

commit 490d84f6d73c12f4204241cff8651eed60aae914 upstream.

If the wait for completion was interrupted, then make sure to cancel
any delayed work.

This can only happen if a transmit is waiting for a reply, and you press
Ctrl-C or reboot/poweroff or something like that which interrupts the
thread waiting for the reply and then proceeds to delete the CEC message.

Since the delayed work wasn't canceled, once it would trigger it referred
to stale data and resulted in a kernel oops.

Fixes: 7ec2b3b941a6 ("cec: add new tx/rx status bits to detect aborts/timeouts")
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: <stable@vger.kernel.org>      # for v4.18 and up
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/cec/cec-adap.c b/drivers/media/cec/cec-adap.c
index 72bcd0917dff43c14c520837f36cc7148bb7afe8..fecba7ddcd008882c359b53d2748c90915353977 100644 (file)
--- a/drivers/media/cec/cec-adap.c
+++ b/drivers/media/cec/cec-adap.c
@@ -815,6 +815,8 @@ int cec_transmit_msg_fh(struct cec_adapter *adap, struct cec_msg *msg,
         */
        mutex_unlock(&adap->lock);
        wait_for_completion_killable(&data->c);
+       if (!data->completed)
+               cancel_delayed_work_sync(&data->work);
        mutex_lock(&adap->lock);
 
        /* Cancel the transmit if it was interrupted */