[PATCH] drivers/media/rc: Ensure usb_submit_urb() is not called if write is in progress

[Gautam Menghani]

The warning "URB submitted while active" is reported if the function
send_packet() in imon.c is called if a write is already is in progress.
Add a check to return -EBUSY in case a write is already is in progress.
Also, mark tx.busy as false after transmission is completed.

Fixes: 21677cfc562a ("V4L/DVB: ir-core: add imon driver")
Cc: hdanton@xxxxxxxx
Suggested-by: hdanton@xxxxxxxx
Link: https://syzkaller.appspot.com/bug?id=e378e6a51fbe6c5cc43e34f131cc9a315ef0337e
Reported-by: syzbot+0c3cb6dc05fbbdc3ad66@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Gautam Menghani <gautammenghani201@xxxxxxxxx>
---
 drivers/media/rc/imon.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
index 735b925da998..a5b997c2c7e2 100644
--- a/drivers/media/rc/imon.c
+++ b/drivers/media/rc/imon.c
@@ -598,6 +598,8 @@ static int send_packet(struct imon_context *ictx)
 	int retval = 0;
 	struct usb_ctrlrequest *control_req = NULL;
 
+	if (ictx->tx.busy)
+		return -EBUSY;
 	/* Check if we need to use control or interrupt urb */
 	if (!ictx->tx_control) {
 		pipe = usb_sndintpipe(ictx->usbdev_intf0,
@@ -654,6 +656,7 @@ static int send_packet(struct imon_context *ictx)
 			pr_err_ratelimited("task interrupted\n");
 		}
 		mutex_lock(&ictx->lock);
+		ictx->tx.busy = false;
 
 		retval = ictx->tx.status;
 		if (retval)
-- 
2.34.1