linux-kernel - [PATCH] media: pvrusb2: fix URB leak in pvr2_send_request

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Message-ID: <20251220182419.390675-1-szymonwilczek@gmx.com>
Date: Sat, 20 Dec 2025 19:24:19 +0100
From: Szymon Wilczek <szymonwilczek@....com>
To: isely@...ox.com,
	mchehab@...nel.org
Cc: linux-media@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	syzkaller-bugs@...glegroups.com,
	Szymon Wilczek <szymonwilczek@....com>,
	syzbot+405dcd13121ff75a9e16@...kaller.appspotmail.com
Subject: [PATCH] media: pvrusb2: fix URB leak in pvr2_send_request_ex

When pvr2_send_request_ex() submits a write URB successfully but fails to submit the read URB (e.g. returns -ENOMEM), it returns immediately without waiting for the write URB to complete. Since the driver reuses the same URB structure, a subsequent call to pvr2_send_request_ex() attempts to submit the still-active write URB, triggering a 'URB submitted while active' warning in usb_submit_urb().

Fix this by ensuring the write URB is unlinked and waited upon if the read URB submission fails.

Reported-by: syzbot+405dcd13121ff75a9e16@...kaller.appspotmail.com

Closes: https://syzkaller.appspot.com/bug?extid=405dcd13121ff75a9e16
Signed-off-by: Szymon Wilczek <szymonwilczek@....com>
---
 drivers/media/usb/pvrusb2/pvrusb2-hdw.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
index b32bb906a9de..5807734ae26c 100644
--- a/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
+++ b/drivers/media/usb/pvrusb2/pvrusb2-hdw.c
@@ -3709,6 +3709,11 @@ status);
 				   "Failed to submit read-control URB status=%d",
 status);
 			hdw->ctl_read_pend_flag = 0;
+			if (hdw->ctl_write_pend_flag) {
+				usb_unlink_urb(hdw->ctl_write_urb);
+				while (hdw->ctl_write_pend_flag)
+					wait_for_completion(&hdw->ctl_done);
+			}
 			goto done;
 		}
 	}
-- 
2.52.0