[PATCH] media: pvrusb2: fix URB pending flag leak on invalid endpoint

Nguyen Quang Le Kien <[email protected]> Mon, 3 Aug 2026 18:40:08 +0800
Newsgroups org.kernel.vger.linux-media,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
In pvr2_send_request_ex(), when usb_urb_ep_type_check() fails for either
the write or read control endpoint, the code returned -EINVAL directly
without clearing the corresponding pending flags (ctl_write_pend_flag or
ctl_read_pend_flag) or going through the done: cleanup path.

This left the pending flags set while the URBs were never actually
submitted. On the next call to pvr2_send_request_ex(), the URBs would be
filled and submitted while the kernel still considered them active,
triggering the WARNING "URB submitted while active" in usb_submit_urb().

Fix this by:
- Clearing the pending flag before returning on invalid endpoint
- Using goto done instead of direct return to go through proper cleanup
- For the read endpoint case, unlinking the write URB if it was already
  submitted and waiting for its completion before returning

Reported-by: [email protected]
Closes: https://syzkaller.appspot.com/bug?extid=20fef510634faf733060
Signed-off-by: Nguyen Quang Le Kien <[email protected]>
---
 drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
index 3c270ef00..3a857e95b 100644
--- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
@@ -3669,7 +3669,9 @@ static int pvr2_send_request_ex(struct pvr2_hdw *hdw,
 			pvr2_trace(
 				PVR2_TRACE_ERROR_LEGS,
 				"Invalid write control endpoint");
-			return -EINVAL;
+			hdw->ctl_write_pend_flag = 0;
+			status = -EINVAL;
+			goto done;
 		}
 		status = usb_submit_urb(hdw->ctl_write_urb,GFP_KERNEL);
 		if (status < 0) {
@@ -3699,7 +3701,13 @@ status);
 			pvr2_trace(
 				PVR2_TRACE_ERROR_LEGS,
 				"Invalid read control endpoint");
-			return -EINVAL;
+			hdw->ctl_read_pend_flag = 0;
+			status = -EINVAL;
+			if (hdw->ctl_write_pend_flag) {
+				usb_unlink_urb(hdw->ctl_write_urb);
+				wait_for_completion(&hdw->ctl_done);
+			}
+			goto done;
 		}
 		status = usb_submit_urb(hdw->ctl_read_urb,GFP_KERNEL);
 		if (status < 0) {
-- 
2.34.1