kernel BUG in submit_bh_wbc

Status: upstream: reported on 2026/08/11 15:13
Reported-by: syzbot+0e25ce8d777866a3bd1d@syzkaller.appspotmail.com
First crash: 2d08h, last: 2d08h
▶ ▼ Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 kernel BUG in submit_bh_wbc origin:lts-only -1 syz, C done 19 798d 1227d 3/3 fixed on 2024/07/20 06:27
upstream kernel BUG at fs/buffer.c:LINE! nilfs -1 syz, C done error 567 856d 3038d 25/29 fixed on 2024/04/10 03:59
upstream kernel BUG in submit_bh_wbc (2) udf -1 syz, C done 123 735d 840d 27/29 fixed on 2024/08/14 03:44
linux-4.14 kernel BUG at fs/buffer.c:LINE! -1 syz, C error 59 1270d 2665d 0/1 upstream: reported C repro on 2019/04/27 19:47
linux-6.1 kernel BUG in submit_bh_wbc (2) origin:lts-only -1 syz, C inconclusive 280 3d22h 748d 0/3 upstream: reported C repro on 2024/07/26 16:49
linux-4.19 kernel BUG at fs/buffer.c:LINE! (2) udf ext4 -1 syz, C error 31 1277d 2091d 0/1 upstream: reported C repro on 2020/11/21 07:48
android-54 kernel BUG at fs/buffer.c:LINE! ext4 -1 syz, C 4762 446d 2396d 0/2 upstream: reported C repro on 2020/01/21 13:12
upstream kernel BUG in submit_bh_wbc (3) nilfs fs -1 syz, C done 18 661d 668d 28/29 fixed on 2024/11/12 23:31
linux-5.15 kernel BUG in submit_bh_wbc -1 syz, C error 8 888d 1166d 0/3 auto-obsoleted due to no activity on 2024/06/16 14:58
upstream kernel BUG in submit_bh_wbc nilfs -1 syz, C done 10 841d 850d 25/29 fixed on 2024/04/24 18:26
android-6-1 kernel BUG in submit_bh_wbc missing-backport origin:lts -1 syz, C done done 2574 3d10h 1155d 0/2 upstream: reported C repro on 2023/06/15 00:20

Sample crash report:
------------[ cut here ]------------
kernel BUG at fs/buffer.c:2795!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 6557 Comm: kmmpd-loop0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:submit_bh_wbc+0x566/0x580 fs/buffer.c:2795
Code: e8 af f5 87 ff be 00 10 00 00 48 c7 c7 a0 6f 26 8d 4c 89 ea e8 eb 77 67 02 e9 8b fe ff ff e8 91 f5 87 ff 0f 0b e8 8a f5 87 ff <0f> 0b e8 83 f5 87 ff 0f 0b e8 7c f5 87 ff 0f 0b e8 75 f5 87 ff 0f
RSP: 0018:ffffc90003167cc0 EFLAGS: 00010293
RAX: ffffffff81ff7c96 RBX: 0000000000000000 RCX: ffff88802412da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000003801 R08: ffff88805d19048f R09: 1ffff1100ba32091
R10: dffffc0000000000 R11: ffffed100ba32092 R12: 1ffff1100ba32091
R13: 0000000000000000 R14: ffff88805d190488 R15: ffff88807da9e000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2da1dff8 CR3: 0000000025758000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 write_mmp_block_thawed+0x3b1/0x540 fs/ext4/mmp.c:51
 write_mmp_block+0x129/0x390 fs/ext4/mmp.c:67
 kmmpd+0x344/0x990 fs/ext4/mmp.c:178
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:submit_bh_wbc+0x566/0x580 fs/buffer.c:2795
Code: e8 af f5 87 ff be 00 10 00 00 48 c7 c7 a0 6f 26 8d 4c 89 ea e8 eb 77 67 02 e9 8b fe ff ff e8 91 f5 87 ff 0f 0b e8 8a f5 87 ff <0f> 0b e8 83 f5 87 ff 0f 0b e8 7c f5 87 ff 0f 0b e8 75 f5 87 ff 0f
RSP: 0018:ffffc90003167cc0 EFLAGS: 00010293
RAX: ffffffff81ff7c96 RBX: 0000000000000000 RCX: ffff88802412da00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000003801 R08: ffff88805d19048f R09: 1ffff1100ba32091
R10: dffffc0000000000 R11: ffffed100ba32092 R12: 1ffff1100ba32091
R13: 0000000000000000 R14: ffff88805d190488 R15: ffff88807da9e000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd9981ef2f8 CR3: 0000000025758000 CR4: 00000000003506f0

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/11 15:12 linux-6.6.y d27334b2888c 71790083 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan kernel BUG in submit_bh_wbc
* Struck through repros no longer work on HEAD.