syzbot


WARNING in firmware_fallback_sysfs (2)

Status: upstream: reported on 2024/08/09 15:45
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+8f06445357a052a92657@syzkaller.appspotmail.com
First crash: 698d, last: 1d21h
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ID Workflow Result Correct Bug Created Started Finished Revision Error
268cddb5-4000-402c-b792-fe1b403afe24 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 c69befb30ac10e158cc9d1557b508ee3f0eca1de

			
		
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Title Replies (including bot) Last reply
[syzbot] [kernel?] WARNING in firmware_fallback_sysfs (2) 0 (1) 2024/08/09 15:45
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in firmware_fallback_sysfs usb fs -1 C error error 3432 811d 1949d 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 C error 291 5d00h 1196d 0/3 upstream: reported C repro on 2023/03/26 17:15
linux-6.6 WARNING in firmware_fallback_sysfs origin:lts-only -1 C inconclusive 533 33d 383d 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 C error 254 12d 1196d 0/3 upstream: reported C repro on 2023/03/26 16:24

Sample crash report:
pvrusb2: Giving up since device microcontroller firmware appears to be missing.
pvrusb2: Failed to submit write-control URB status=-19
usb 3-1: Direct firmware load for v4l-pvrusb2-29xxx-01.fw failed with error -2
usb 3-1: Falling back to sysfs fallback for: v4l-pvrusb2-29xxx-01.fw
------------[ cut here ]------------
ret
WARNING: drivers/base/firmware_loader/fallback.c:148 at fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:148 [inline], CPU#0: pvrusb2-context/2365
WARNING: drivers/base/firmware_loader/fallback.c:148 at firmware_fallback_sysfs+0x755/0xa40 drivers/base/firmware_loader/fallback.c:238, CPU#0: pvrusb2-context/2365
Modules linked in:
CPU: 0 UID: 0 PID: 2365 Comm: pvrusb2-context Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:148 [inline]
RIP: 0010:firmware_fallback_sysfs+0x755/0xa40 drivers/base/firmware_loader/fallback.c:238
Code: 9a fb e9 48 fc ff ff e8 d9 8d 9a fb c6 05 17 08 15 0a 01 48 c7 c7 60 26 76 8c e8 36 db fb fa e9 70 fc ff ff e8 bc 8d 9a fb 90 <0f> 0b 90 4c 89 f7 48 c7 c6 60 27 76 8c 4c 89 e2 e8 d6 53 00 fb e9
RSP: 0018:ffffc9000656f680 EFLAGS: 00010293
RAX: ffffffff862be404 RBX: dffffc0000000000 RCX: ffff88802c855d00
RDX: 0000000000000000 RSI: 00000000fffffff5 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff905767f7 R09: 1ffffffff20aecfe
R10: dffffc0000000000 R11: fffffbfff20aecff R12: ffffffff8cd0fa00
R13: 0000000000001770 R14: ffff88803154b0b0 R15: 00000000fffffff5
FS:  0000000000000000(0000) GS:ffff888124f5d000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000404030 CR3: 000000007fd88000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 _request_firmware+0x1049/0x1780 drivers/base/firmware_loader/main.c:898
 request_firmware+0x36/0x50 drivers/base/firmware_loader/main.c:948
 pvr2_locate_firmware+0xb3/0x500 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:1359
 pvr2_upload_firmware1+0x1bd/0x940 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+0x425/0x3c60 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2338
 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:111 [inline]
 pvr2_context_thread_func+0x504/0xc10 drivers/media/usb/pvrusb2/pvrusb2-context.c:158
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (260):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/02 16:04 upstream 4a50a141f05a 2b70b115 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/28 07:20 upstream 780d569e6c4b fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in firmware_fallback_sysfs
2026/06/26 09:40 upstream 4edcdefd4083 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root WARNING in firmware_fallback_sysfs
2026/06/26 03:42 upstream 962528fef902 432fd51a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/25 16:38 upstream ab9de95c9cf9 432fd51a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/24 19:26 upstream 840ef6c78e6a c1da772e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/24 01:53 upstream f31c00c377cc 042555ff .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/23 09:30 upstream 502d801f0ab0 4b1d8f01 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/21 17:15 upstream 390d73adf896 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in firmware_fallback_sysfs
2026/06/20 16:18 upstream 1a3746ccbb0a 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/19 14:32 upstream 8c13415c8a43 d7ffd47b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/18 14:17 upstream e771677c937d a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/17 05:30 upstream 6b5a2b7d9bc1 62cc6db3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/17 01:32 upstream 6b5a2b7d9bc1 0e4b3e40 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/15 21:16 upstream 0e0611827f33 50bb0618 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/11 16:17 upstream 9716c086c8e8 d93a6ab6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/03 18:21 upstream ba3e43a9e601 234057e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/03 08:33 upstream ba3e43a9e601 3c0d2131 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/02 21:07 upstream 6f3ed7fec72f 62fe1528 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/02 06:31 upstream e43ffb69e043 1095583b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/30 17:24 upstream f5e5d3509bff 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/30 16:02 upstream f5e5d3509bff 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/26 17:23 upstream e8c2f9fdadee a3e47276 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/26 14:22 upstream e8c2f9fdadee a3e47276 .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
2026/05/22 11:15 upstream 6779b50faa56 e16cf9f3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/20 18:48 upstream 27fa82620cba 62fb93a2 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/14 21:11 upstream 66182ca873a4 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/14 15:17 upstream e1914add2799 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/13 08:31 upstream c21b90f77687 a0949470 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/12 15:39 upstream 50897c955902 d5b1a17d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/12 05:00 upstream 50897c955902 d168f260 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/12 01:20 upstream 50897c955902 d168f260 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/11 18:20 upstream 5d6919055dec e6eb7c0b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/07 20:31 upstream 19cbc75c56c0 e358bca5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/07 03:40 upstream 74fe02ce122a cbcd9ea0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/04 08:17 upstream 6d35786de281 a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/01 14:01 upstream 26fd6bff2c05 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING in firmware_fallback_sysfs
2026/04/30 10:03 upstream 57b8e2d666a3 005438fc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/28 19:51 upstream dca922e019dd b4209743 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/28 14:31 upstream 3b3bea6d4b9c b4209743 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/23 16:53 upstream 2e6803928193 4c3406dc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/09 16:31 upstream 7f87a5ea75f0 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/09 14:13 upstream 7f87a5ea75f0 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/03 08:11 upstream d8a9a4b11a13 4440e7c2 .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
2025/07/19 09:15 upstream 4871b7cb27f4 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root 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
2026/05/12 09:30 upstream 50897c955902 d5b1a17d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in firmware_fallback_sysfs
2026/04/20 09:02 upstream c1f49dea2b8f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in firmware_fallback_sysfs
2026/04/15 11:28 upstream 508fed679541 e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in firmware_fallback_sysfs
2026/04/14 17:12 upstream d60bc1401583 362d1323 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING in firmware_fallback_sysfs
2025/10/19 05:45 upstream 1c64efcb083c 1c8c8cd8 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING in firmware_fallback_sysfs
2026/02/02 07:26 upstream 9f2693489ef8 6b8752f2 .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
2026/04/15 01:17 net-next 35c2c39832e5 e2e976a8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce WARNING in firmware_fallback_sysfs
2026/06/20 18:48 linux-next ec039126b7fa 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/05/12 18:56 linux-next e98d21c170b0 d5b1a17d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/12 05:30 linux-next cc13002a9f98 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/04/10 00:32 linux-next cc13002a9f98 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in firmware_fallback_sysfs
2026/03/03 15:42 linux-next c025f6cf4209 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in firmware_fallback_sysfs
* Struck through repros no longer work on HEAD.