Le 19/02/2024 à 14:10, syzbot a écrit :
syzbot has bisected this issue to:
commit c838530d230bc638d79b78737fc4488ffc28c1ee
Author: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
Date: Thu Nov 9 16:34:59 2023 +0000
media: media videobuf2: Be more flexible on the number of queue stored buffers
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=166dc872180000
start commit: b401b621758e Linux 6.8-rc5
git tree: upstream
final oops: https://syzkaller.appspot.com/x/report.txt?x=156dc872180000
console output: https://syzkaller.appspot.com/x/log.txt?x=116dc872180000
kernel config: https://syzkaller.appspot.com/x/.config?x=eff9f3183d0a20dd
dashboard link: https://syzkaller.appspot.com/bug?extid=3b1d4b3d5f7a358bf9a9
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13ffaae8180000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13ef909c180000
Reported-by: syzbot+3b1d4b3d5f7a358bf9a9@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: c838530d230b ("media: media videobuf2: Be more flexible on the number of queue stored buffers")
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
Hans,
I think the issue occur because of this part of the commit:
@@ -1264,7 +1264,7 @@ void vb2_video_unregister_device(struct video_device *vdev)
*/
get_device(&vdev->dev);
video_unregister_device(vdev);
- if (vdev->queue && vdev->queue->owner) {
+ if (vdev->queue) {
struct mutex *lock = vdev->queue->lock ?
vdev->queue->lock : vdev->lock;
but I wonder if the correction shouldn't be to remove usbtv->vb2q_lock mutex in usbtv_video_free().
Any opinion ?
Regards,
Benjamin
