WARNING in firmware_fallback_sysfs (2)

Status: upstream: reported on 2026/08/04 21:17
Reported-by: syzbot+88ad674700b1b2130bf6@syzkaller.appspotmail.com
First crash: 17d, last: 4d13h
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in firmware_fallback_sysfs usb fs -1 syz, C error error 3432 859d 1997d 0/29 auto-obsoleted due to no activity on 2024/06/24 11:12
linux-5.15 WARNING in firmware_fallback_sysfs missing-backport origin:upstream -1 syz, C error 295 17d 1244d 0/3 upstream: reported C repro on 2023/03/26 17:15
linux-6.6 WARNING in firmware_fallback_sysfs origin:lts-only -1 syz, C inconclusive 581 5d02h 431d 0/2 upstream: reported C repro on 2025/06/17 10:18
linux-6.1 WARNING in firmware_fallback_sysfs origin:upstream missing-backport -1 syz, C error 256 29d 1244d 3/3 fixed on 2026/07/24 15:33
upstream WARNING in firmware_fallback_sysfs (2) prio:low kernel -1 360 16h05m 742d 0/29 upstream: reported on 2024/08/09 15:45

Sample crash report:
usb 5-1: reset high-speed USB device number 2 using dummy_hcd
usb 5-1: device descriptor read/8, error -32
usb 5-1: Direct firmware load for ueagle-atm/930-fpga.bin failed with error -2
usb 5-1: Falling back to sysfs fallback for: ueagle-atm/930-fpga.bin
------------[ cut here ]------------
WARNING: CPU: 1 PID: 129 at drivers/base/firmware_loader/fallback.c:144 fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:144 [inline]
WARNING: CPU: 1 PID: 129 at drivers/base/firmware_loader/fallback.c:144 firmware_fallback_sysfs+0x71e/0x950 drivers/base/firmware_loader/fallback.c:234
Modules linked in:
CPU: 1 PID: 129 Comm: kworker/1:2 Tainted: G S                 syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:144 [inline]
RIP: 0010:firmware_fallback_sysfs+0x71e/0x950 drivers/base/firmware_loader/fallback.c:234
Code: df e8 36 6a f9 ff 45 89 e7 eb bc e8 bc 01 67 fc c6 05 14 75 f1 08 01 48 c7 c7 20 06 04 8b e8 79 b9 09 05 eb a7 e8 a2 01 67 fc <0f> 0b 4c 89 f7 48 c7 c6 00 07 04 8b 4c 89 e2 e8 83 ba 0d 05 eb 8c
RSP: 0018:ffffc90002d46ba0 EFLAGS: 00010283
RAX: ffffffff851b2c7e RBX: dffffc0000000000 RCX: 0000000000100000
RDX: ffffc9001b2c5000 RSI: 00000000000654eb RDI: 00000000000654ec
RBP: 0000000000000001 R08: ffffffff90b102af R09: 1ffffffff2162055
R10: dffffc0000000000 R11: fffffbfff2162056 R12: ffffffff8b3dd9c0
R13: 0000000000001770 R14: ffff888077a4e0a8 R15: 00000000fffffff5
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2c9c7e CR3: 000000000c88e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 _request_firmware+0xccb/0x1280 drivers/base/firmware_loader/main.c:884
 request_firmware+0x32/0x50 drivers/base/firmware_loader/main.c:933
 load_XILINX_firmware drivers/usb/atm/ueagle-atm.c:1920 [inline]
 uea_boot drivers/usb/atm/ueagle-atm.c:2158 [inline]
 uea_bind+0x9f0/0x1990 drivers/usb/atm/ueagle-atm.c:2561
 usbatm_usb_probe+0x371/0x1d20 drivers/usb/atm/usbatm.c:1057
 uea_probe+0x1fc/0x430 drivers/usb/atm/ueagle-atm.c:2623
 usb_probe_interface+0x5be/0xae0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xb40 drivers/base/dd.c:638
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:834
 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:962
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a7/0x480 drivers/base/dd.c:1034
 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
 device_add+0xbcf/0x1050 drivers/base/core.c:3712
 usb_set_configuration+0x19d5/0x2030 drivers/usb/core/message.c:2223
 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238
 usb_probe_device+0x126/0x250 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x24a/0xb40 drivers/base/dd.c:638
 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:804
 driver_probe_device+0x4f/0x420 drivers/base/dd.c:834
 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:962
 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429
 __device_attach+0x2a7/0x480 drivers/base/dd.c:1034
 bus_probe_device+0xba/0x1d0 drivers/base/bus.c:489
 device_add+0xbcf/0x1050 drivers/base/core.c:3712
 usb_new_device+0xa01/0x15e0 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+0x2b2f/0x5200 drivers/usb/core/hub.c:5899
 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaf5/0x12a0 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 (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/17 22:40 linux-6.1.y e4f7d8be268e 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/17 22:09 linux-6.1.y e4f7d8be268e 905244d6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/05 02:00 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/05 01:39 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/05 01:02 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/05 00:40 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/05 00:34 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/05 00:31 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/05 00:20 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/04 23:29 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/04 23:25 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/04 23:14 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/04 23:14 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/04 22:57 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
2026/08/04 21:17 linux-6.1.y fb28aa725e05 d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan WARNING in firmware_fallback_sysfs
* Struck through repros no longer work on HEAD.