------------[ cut here ]------------
kernel BUG at fs/buffer.c:2714!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 785 Comm: kmmpd-loop0 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:submit_bh_wbc+0x4c9/0x4f0 fs/buffer.c:2714
Code: c3 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c bd fe ff ff 48 89 df e8 68 e3 e7 ff e9 b0 fe ff ff e8 1e b7 a2 ff 0f 0b e8 17 b7 a2 ff <0f> 0b e8 10 b7 a2 ff 0f 0b e8 09 b7 a2 ff 0f 0b e8 02 b7 a2 ff 0f
RSP: 0018:ffffc9001292fca0 EFLAGS: 00010293

RAX: ffffffff81ce92a9 RBX: 0000000000000000 RCX: ffff88811ca81440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9001292fcf0 R08: ffff88811766034f R09: 1ffff11022ecc069
R10: dffffc0000000000 R11: ffffed1022ecc06a R12: 0000000000000000
R13: 1ffff11022ecc069 R14: ffff888117660348 R15: 0000000000003801
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4c19441ff8 CR3: 000000012e881000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 submit_bh+0x1f/0x30 fs/buffer.c:2755
 write_mmp_block_thawed+0x397/0x510 fs/ext4/mmp.c:51
 write_mmp_block+0x138/0x2b0 fs/ext4/mmp.c:67
 kmmpd+0x3ce/0x950 fs/ext4/mmp.c:178
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:submit_bh_wbc+0x4c9/0x4f0 fs/buffer.c:2714
Code: c3 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c bd fe ff ff 48 89 df e8 68 e3 e7 ff e9 b0 fe ff ff e8 1e b7 a2 ff 0f 0b e8 17 b7 a2 ff <0f> 0b e8 10 b7 a2 ff 0f 0b e8 09 b7 a2 ff 0f 0b e8 02 b7 a2 ff 0f
RSP: 0018:ffffc9001292fca0 EFLAGS: 00010293

RAX: ffffffff81ce92a9 RBX: 0000000000000000 RCX: ffff88811ca81440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9001292fcf0 R08: ffff88811766034f R09: 1ffff11022ecc069
R10: dffffc0000000000 R11: ffffed1022ecc06a R12: 0000000000000000
R13: 1ffff11022ecc069 R14: ffff888117660348 R15: 0000000000003801
FS:  0000000000000000(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557002d908 CR3: 0000000135657000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400