WARNING in media_create_pad_link (2)

Status: upstream: reported C repro on 2026/03/17 03:30
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+e9468c825031b925db7b@syzkaller.appspotmail.com
First crash: 132d, last: 101d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/04/02 linux-6.1.y (ToT) 1989cd3d56e2 C [report] WARNING in media_create_pad_link
2026/03/19 upstream (ToT) 8a30aeb0d1b4 C Didn't crash
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 WARNING in media_create_pad_link (2) origin:lts-only -1 C error 4 117d 132d 0/3 auto-obsoleted due to no activity on 2026/07/09 20:59
upstream WARNING in media_create_pad_link (2) usb media -1 C error done 11 292d 495d 29/29 fixed on 2025/11/14 14:05
linux-5.15 WARNING in media_create_pad_link origin:upstream -1 C error 7 592d 1225d 0/3 auto-obsoleted due to no activity on 2025/03/22 03:16
linux-6.1 WARNING in media_create_pad_link origin:upstream -1 C error 2 693d 1225d 3/3 fixed on 2024/12/14 20:01
upstream WARNING in media_create_pad_link usb media -1 C done done 104 612d 2264d 28/29 fixed on 2024/12/16 09:50
▶ ▼ Fix bisection attempts (3)
Created Duration User Patch Repo Result
2026/07/23 16:17 3h06m fix candidate upstream OK (0) job log
2026/06/09 00:12 13m fix candidate upstream error job log
2026/04/03 09:57 1m fix candidate upstream error job log

Sample crash report:
usb 1-1: New USB device found, idVendor=174f, idProduct=5212, bcdDevice=40.10
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: syz
usb 1-1: Manufacturer: syz
usb 1-1: SerialNumber: syz
usb 1-1: Found UVC 7.ff device syz (174f:5212)
uvcvideo 1-1:6.220: Entity type for entity Output 4 was not initialized!
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4338 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: 4338 Comm: kworker/1:8 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
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: 0018:ffffc90003186ab8 EFLAGS: 00010293
RAX: ffffffff86bdec2c RBX: 0000000000000002 RCX: ffff888025240000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000003 R09: 1ffff1100ec88a97
R10: dffffc0000000000 R11: ffffed100ec88a98 R12: ffff88802f1748b8
R13: ffff88802f174880 R14: 0000000000000003 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b908fb5828 CR3: 000000005b4dd000 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
 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
 __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
 __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
 </TASK>

Crashes (16):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/19 03:34 linux-6.1.y f2ddafa93a25 0199f9a1 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/03/19 02:45 linux-6.1.y f2ddafa93a25 0199f9a1 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/16 22:04 linux-6.1.y 8e8fc038cad5 4743f87d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/13 07:44 linux-6.1.y 8e8fc038cad5 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/09 14:43 linux-6.1.y 1989cd3d56e2 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/09 14:43 linux-6.1.y 1989cd3d56e2 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/09 12:08 linux-6.1.y 1989cd3d56e2 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/09 12:08 linux-6.1.y 1989cd3d56e2 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/09 00:14 linux-6.1.y 1989cd3d56e2 d9b7f621 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/09 00:13 linux-6.1.y 1989cd3d56e2 d9b7f621 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/01 05:24 linux-6.1.y 1989cd3d56e2 fb8b2c26 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/01 05:24 linux-6.1.y 1989cd3d56e2 fb8b2c26 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/03/17 03:29 linux-6.1.y f2ddafa93a25 0737c18f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/03/17 03:29 linux-6.1.y f2ddafa93a25 0737c18f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in media_create_pad_link
2026/04/13 06:17 linux-6.1.y 8e8fc038cad5 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in media_create_pad_link
2026/04/09 08:46 linux-6.1.y 1989cd3d56e2 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 WARNING in media_create_pad_link
* Struck through repros no longer work on HEAD.