WARNING in firmware_fallback_sysfs (2)

Status: upstream: reported C repro on 2024/08/09 15:45
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+8f06445357a052a92657@syzkaller.appspotmail.com
First crash: 765d, last: 5d22h
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
94968d44 repro-c Reproduced: ✅ WARNING in firmware_fallback_sysfs (2) 2026/09/03 19:38 2026/09/03 19:38 2026/09/03 20:39 d2e5fb95
268cddb5 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in firmware_fallback_sysfs (2) 2026/05/26 07:21 2026/05/26 07:21 2026/05/26 08:21 c69befb3
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] WARNING in firmware_fallback_sysfs (2) 0 (2) 2026/09/04 13:07
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 878d 2016d 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 36d 1263d 0/3 upstream: reported C repro on 2023/03/26 17:15
linux-6.1 WARNING in firmware_fallback_sysfs (2) -1 15 23d 36d 0/3 upstream: reported on 2026/08/04 21:17
linux-6.6 WARNING in firmware_fallback_sysfs origin:lts-only -1 syz, C inconclusive 581 24d 450d 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 48d 1263d 3/3 fixed on 2026/07/24 15:33
Last patch testing requests (1)
Created Duration User Patch Repo Result
2026/09/04 12:52 14m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git bc35965f6940a9bf834d54187b6088b8eb09206d report job log log

Sample crash report:
usb 7-1: Falling back to sysfs fallback for: v4l-pvrusb2-160xxx-01.fw
------------[ cut here ]------------
ret
WARNING: drivers/base/firmware_loader/fallback.c:158 at fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:158 [inline], CPU#0: pvrusb2-context/2510
WARNING: drivers/base/firmware_loader/fallback.c:158 at firmware_fallback_sysfs+0x6ef/0xc60 drivers/base/firmware_loader/fallback.c:248, CPU#0: pvrusb2-context/2510
Modules linked in:
CPU: 0 UID: 0 PID: 2510 Comm: pvrusb2-context Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:158 [inline]
RIP: 0010:firmware_fallback_sysfs+0x6ef/0xc60 drivers/base/firmware_loader/fallback.c:248
Code: ff ff e9 2f 42 d0 fa e8 af ab 9b fb e8 6a 31 5f fb 31 ff 89 c3 89 c6 e8 0f a6 9b fb 85 db 0f 84 f5 fa ff ff e8 92 ab 9b fb 90 <0f> 0b 90 48 8b 3c 24 4c 89 e2 48 c7 c6 20 f2 93 8c e8 6b 11 d0 fa
RSP: 0018:ffffc90007d1f8d0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 00000000fffffff5 RCX: 0000000000000000
RDX: ffff88802e7e2580 RSI: ffffffff8670447e RDI: ffff88802e7e2580
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000fffffff5 R11: 000000000000761b R12: ffffffff8cff0200
R13: ffff888027cff200 R14: 0000000000001770 R15: ffff888027cff210
FS:  0000000000000000(0000) GS:ffff8880d5b60000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f735b1f0980 CR3: 0000000035e42000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 _request_firmware+0xfd7/0x13c0 drivers/base/firmware_loader/main.c:898
 request_firmware+0x35/0x50 drivers/base/firmware_loader/main.c:948
 pvr2_locate_firmware+0x8f/0x330 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:1359
 pvr2_upload_firmware1+0x1ca/0x920 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:1426
 pvr2_hdw_setup_low drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2107 [inline]
 pvr2_hdw_setup drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2261 [inline]
 pvr2_hdw_initialize+0x3e6/0x3710 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2338
 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:111 [inline]
 pvr2_context_thread_func+0x253/0x920 drivers/media/usb/pvrusb2/pvrusb2-context.c:158
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (371):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/04 13:07 git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git bc35965f6940 2f52988a .config console log report C ci-qemu-upstream WARNING in firmware_fallback_sysfs
2026/08/30 10:41 upstream 08dbfad3f504 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/25 19:31 upstream 66498c75b4f8 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/24 22:50 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/24 18:13 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/24 15:01 upstream 0a0d1d55dad5 23caa175 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/23 18:07 upstream 66fb95a52111 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/21 20:07 upstream 818bebeb63dd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/20 23:01 upstream 9328b3b03bdc 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/19 12:42 upstream 0f23d56f17fd 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/18 08:41 upstream ff68e5f557f6 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/17 07:51 upstream dcb68831eac7 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in firmware_fallback_sysfs
2026/08/15 09:30 upstream 15ef2f78c49d 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/15 03:18 upstream 2f1baf1fc892 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/13 23:08 upstream 3aa1dcaa4f6f a9ede23c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/13 18:00 upstream 3d6d817622b0 a9ede23c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/13 11:01 upstream 3d6d817622b0 67796a05 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/12 23:36 upstream 3d6d817622b0 7ae4acc7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/11 17:31 upstream f5bbbfec59b4 37a258dd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/10 19:02 upstream db2ddb871435 039457bd .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/09 18:04 upstream 06cf61899d64 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/08 04:24 upstream 9a143525f62b e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/07 11:55 upstream f9a2394a2348 e4ef95d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/07 03:30 upstream 0d8395707651 c38879ea .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/04 22:58 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in firmware_fallback_sysfs
2026/08/04 18:47 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root WARNING in firmware_fallback_sysfs
2026/08/04 17:16 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in firmware_fallback_sysfs
2026/08/04 16:03 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in firmware_fallback_sysfs
2026/08/04 15:03 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in firmware_fallback_sysfs
2026/08/04 14:24 upstream 848acc8ffe1b d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in firmware_fallback_sysfs
2026/08/03 02:53 upstream bd1dde877520 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/02 11:24 upstream 2d2338c93da7 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/07/28 13:41 upstream 62cc90241548 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/07/28 12:01 upstream 62cc90241548 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/07/28 11:52 upstream 62cc90241548 45ae1df4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/23 00:31 upstream cca95436be15 c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/03/09 05:45 upstream 014441d1e4b2 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2025/07/05 12:32 upstream a79a588fc176 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING in firmware_fallback_sysfs
2024/08/05 15:38 upstream de9c2c66ad8e e35c337f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in firmware_fallback_sysfs
2026/08/29 23:00 upstream 08dbfad3f504 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in firmware_fallback_sysfs
2026/08/28 13:09 upstream 1b78070aaef6 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in firmware_fallback_sysfs
2026/08/10 08:18 upstream b9b3e33b70b7 5d63f80b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in firmware_fallback_sysfs
2026/08/04 18:19 upstream 848acc8ffe1b 3c5eaa21 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in firmware_fallback_sysfs
2026/08/04 13:21 upstream 848acc8ffe1b 3c5eaa21 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING in firmware_fallback_sysfs
2026/07/03 17:13 bpf d2c9a99135da 58bf2096 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/04 17:00 net-next 98878ed91b68 85f1bcf2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/29 10:11 bpf-next 9f5b3ffc3f1d 95008c03 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/25 11:16 linux-next 4b18edbd8e70 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/23 01:11 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/21 18:21 linux-next 903c1cf6dff9 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/18 10:00 linux-next e6664f2b33db 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/18 05:46 linux-next 4477a78374a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/18 01:23 linux-next 4477a78374a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/17 23:42 linux-next 4477a78374a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/17 22:25 linux-next 4477a78374a5 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/17 12:02 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in firmware_fallback_sysfs
2026/08/17 10:35 linux-next 4477a78374a5 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in firmware_fallback_sysfs
2026/08/04 20:51 linux-next cc2b5f627e8c d4abbeac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/08/21 01:16 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 8da45c93dfa9 1e72964b .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in firmware_fallback_sysfs
* Struck through repros no longer work on HEAD.