[v5.15] WARNING in media_create_pad_link (2)
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syzbot
Mar 16, 2026, 10:25:25 PM (19 hours ago) Mar 16
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 91d48252ad4b Linux 5.15.202
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=136b5602580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=fdb1feaa214f91bff2d0
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/74e75dfcb812/disk-91d48252.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bfa72aab00f2/vmlinux-91d48252.xz
kernel image: https://storage.googleapis.com/syzbot-assets/47ea72d1c7dc/bzImage-91d48252.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fdb1fe...@syzkaller.appspotmail.com
usb 2-1: Found UVC 7.ff device syz (174f:5212)
uvcvideo 2-1:6.220: Entity type for entity Output 4 was not initialized!
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4236 at drivers/media/mc/mc-entity.c:667 media_create_pad_link+0x98a/0xae0 drivers/media/mc/mc-entity.c:667
Modules linked in:
CPU: 0 PID: 4236 Comm: kworker/0:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:media_create_pad_link+0x98a/0xae0 drivers/media/mc/mc-entity.c:667
Code: 01 00 00 66 ff 03 31 c0 48 83 c4 50 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 04 23 06 fb 0f 0b b8 ea ff ff ff eb e3 e8 f6 22 06 fb <0f> 0b b8 ea ff ff ff eb d5 e8 e8 22 06 fb 0f 0b b8 ea ff ff ff eb
RSP: 0018:ffffc900030ceaa0 EFLAGS: 00010283
RAX: ffffffff8672fe1a RBX: 0000000000000002 RCX: 0000000000100000
RDX: ffffc90013520000 RSI: 000000000002e649 RDI: 000000000002e64a
RBP: 0000000000000000 R08: 0000000000000003 R09: 1ffff11004472e97
R10: dffffc0000000000 R11: ffffed1004472e98 R12: ffff888078424080
R13: ffff88801f7c3080 R14: 0000000000000000 R15: ffff88801f7c31c0
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32907ff8 CR3: 000000002ab83000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
uvc_mc_create_links drivers/media/usb/uvc/uvc_entity.c:50 [inline]
uvc_mc_register_entities+0x6be/0x930 drivers/media/usb/uvc/uvc_entity.c:151
uvc_register_chains+0x3cf/0x4b0 drivers/media/usb/uvc/uvc_driver.c:2360
uvc_probe+0xa356/0xac00 drivers/media/usb/uvc/uvc_driver.c:2505
usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x284/0xc80 drivers/base/dd.c:595
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:979
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3412
usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165
usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x284/0xc80 drivers/base/dd.c:595
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:979
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3412
usb_new_device+0xd65/0x1660 drivers/usb/core/hub.c:2632
hub_port_connect drivers/usb/core/hub.c:5497 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
port_event drivers/usb/core/hub.c:5799 [inline]
hub_event+0x2e4a/0x55e0 drivers/usb/core/hub.c:5881
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 91d48252ad4b Linux 5.15.202
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=136b5602580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=fdb1feaa214f91bff2d0
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/74e75dfcb812/disk-91d48252.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bfa72aab00f2/vmlinux-91d48252.xz
kernel image: https://storage.googleapis.com/syzbot-assets/47ea72d1c7dc/bzImage-91d48252.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fdb1fe...@syzkaller.appspotmail.com
usb 2-1: Found UVC 7.ff device syz (174f:5212)
uvcvideo 2-1:6.220: Entity type for entity Output 4 was not initialized!
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4236 at drivers/media/mc/mc-entity.c:667 media_create_pad_link+0x98a/0xae0 drivers/media/mc/mc-entity.c:667
Modules linked in:
CPU: 0 PID: 4236 Comm: kworker/0:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:media_create_pad_link+0x98a/0xae0 drivers/media/mc/mc-entity.c:667
Code: 01 00 00 66 ff 03 31 c0 48 83 c4 50 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 04 23 06 fb 0f 0b b8 ea ff ff ff eb e3 e8 f6 22 06 fb <0f> 0b b8 ea ff ff ff eb d5 e8 e8 22 06 fb 0f 0b b8 ea ff ff ff eb
RSP: 0018:ffffc900030ceaa0 EFLAGS: 00010283
RAX: ffffffff8672fe1a RBX: 0000000000000002 RCX: 0000000000100000
RDX: ffffc90013520000 RSI: 000000000002e649 RDI: 000000000002e64a
RBP: 0000000000000000 R08: 0000000000000003 R09: 1ffff11004472e97
R10: dffffc0000000000 R11: ffffed1004472e98 R12: ffff888078424080
R13: ffff88801f7c3080 R14: 0000000000000000 R15: ffff88801f7c31c0
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32907ff8 CR3: 000000002ab83000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
uvc_mc_create_links drivers/media/usb/uvc/uvc_entity.c:50 [inline]
uvc_mc_register_entities+0x6be/0x930 drivers/media/usb/uvc/uvc_entity.c:151
uvc_register_chains+0x3cf/0x4b0 drivers/media/usb/uvc/uvc_driver.c:2360
uvc_probe+0xa356/0xac00 drivers/media/usb/uvc/uvc_driver.c:2505
usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x284/0xc80 drivers/base/dd.c:595
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:979
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3412
usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165
usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x284/0xc80 drivers/base/dd.c:595
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
__device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:979
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3412
usb_new_device+0xd65/0x1660 drivers/usb/core/hub.c:2632
hub_port_connect drivers/usb/core/hub.c:5497 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
port_event drivers/usb/core/hub.c:5799 [inline]
hub_event+0x2e4a/0x55e0 drivers/usb/core/hub.c:5881
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot
Mar 16, 2026, 11:30:28 PM (18 hours ago) Mar 16
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: f2ddafa93a25 Linux 6.1.166
syzbot found the following issue on:
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1710a8da580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0605c5af04d7603
dashboard link: https://syzkaller.appspot.com/bug?extid=e9468c825031b925db7b
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5d86a86f0032/disk-f2ddafa9.raw.xz
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
vmlinux: https://storage.googleapis.com/syzbot-assets/aafc10ea040b/vmlinux-f2ddafa9.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f6b46858e7a5/bzImage-f2ddafa9.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
uvcvideo 3-1:6.220: Entity type for entity Output 4 was not initialized!
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4313 at drivers/media/mc/mc-entity.c:1069 media_create_pad_link+0x9ec/0xb80 drivers/media/mc/mc-entity.c:1069
Modules linked in:
CPU: 1 PID: 4313 Comm: kworker/1:5 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:media_create_pad_link+0x9ec/0xb80 drivers/media/mc/mc-entity.c:1069
Workqueue: usb_hub_wq hub_event
Code: 01 00 00 66 ff 03 31 c0 48 83 c4 70 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 92 86 c4 fa 0f 0b b8 ea ff ff ff eb e3 e8 84 86 c4 fa <0f> 0b b8 ea ff ff ff eb d5 e8 76 86 c4 fa 0f 0b b8 ea ff ff ff eb
RSP: 0000:ffffc900041a6ab8 EFLAGS: 00010287
RAX: ffffffff86bdec2c RBX: 0000000000000002 RCX: 0000000000100000
RDX: ffffc9001b15b000 RSI: 000000000002cd6b RDI: 000000000002cd6c
RBP: 0000000000000000 R08: 0000000000000003 R09: 1ffff1100ef4c697
R10: dffffc0000000000 R11: ffffed100ef4c698 R12: ffff88807ccb80b8
R13: ffff88807ccb8080 R14: 0000000000000003 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2079735bdf CR3: 0000000026828000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
uvc_mc_create_links drivers/media/usb/uvc/uvc_entity.c:50 [inline]
uvc_mc_register_entities+0x725/0x9d0 drivers/media/usb/uvc/uvc_entity.c:151
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
uvc_mc_create_links drivers/media/usb/uvc/uvc_entity.c:50 [inline]
uvc_register_chains+0x3cf/0x4b0 drivers/media/usb/uvc/uvc_driver.c:2094
uvc_probe+0xa0bc/0xad20 drivers/media/usb/uvc/uvc_driver.c:2239
usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2aa/0xc70 drivers/base/dd.c:639
call_driver_probe drivers/base/dd.c:-1 [inline]
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:785
driver_probe_device+0x4f/0x420 drivers/base/dd.c:815
__device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:1015
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3697
usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165
usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x2aa/0xc70 drivers/base/dd.c:639
usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293
call_driver_probe drivers/base/dd.c:-1 [inline]
__driver_probe_device+0x18c/0x330 drivers/base/dd.c:785
driver_probe_device+0x4f/0x420 drivers/base/dd.c:815
__device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943
bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
__device_attach+0x2a8/0x480 drivers/base/dd.c:1015
bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489
device_add+0xa00/0xfb0 drivers/base/core.c:3697
usb_new_device+0xd66/0x1650 drivers/usb/core/hub.c:2659
hub_port_connect drivers/usb/core/hub.c:5517 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
port_event drivers/usb/core/hub.c:5817 [inline]
hub_event+0x2dcf/0x5560 drivers/usb/core/hub.c:5899
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
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