------------[ cut here ]------------ kernel BUG at fs/buffer.c:2666! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 9898 Comm: kmmpd-loop0 Not tainted 6.1.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:submit_bh_wbc+0x4ac/0x4d0 fs/buffer.c:2666 Code: 01 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c c0 fe ff ff 48 89 ef e8 e5 67 e2 ff e9 b3 fe ff ff e8 4b 4b 92 ff 0f 0b e8 44 4b 92 ff <0f> 0b e8 3d 4b 92 ff 0f 0b e8 36 4b 92 ff 0f 0b e8 2f 4b 92 ff 0f RSP: 0018:ffffc9000dc9fcc8 EFLAGS: 00010293 RAX: ffffffff81ee731c RBX: 0000000000000000 RCX: ffff888026df5940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000003801 R08: dffffc0000000000 R09: ffffed100eaf61b4 R10: ffffed100eaf61b4 R11: 1ffff1100eaf61b3 R12: 1ffff1100eaf61b3 R13: 0000000000000000 R14: ffff8880757b0d98 R15: ffff88807c2c2000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2e8bea9000 CR3: 00000000278b5000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: write_mmp_block_thawed+0x360/0x4f0 fs/ext4/mmp.c:51 write_mmp_block+0x13e/0x3a0 fs/ext4/mmp.c:67 kmmpd+0x337/0x980 fs/ext4/mmp.c:178 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:submit_bh_wbc+0x4ac/0x4d0 fs/buffer.c:2666 Code: 01 89 e9 80 e1 07 80 c1 03 38 c1 0f 8c c0 fe ff ff 48 89 ef e8 e5 67 e2 ff e9 b3 fe ff ff e8 4b 4b 92 ff 0f 0b e8 44 4b 92 ff <0f> 0b e8 3d 4b 92 ff 0f 0b e8 36 4b 92 ff 0f 0b e8 2f 4b 92 ff 0f RSP: 0018:ffffc9000dc9fcc8 EFLAGS: 00010293 RAX: ffffffff81ee731c RBX: 0000000000000000 RCX: ffff888026df5940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000003801 R08: dffffc0000000000 R09: ffffed100eaf61b4 R10: ffffed100eaf61b4 R11: 1ffff1100eaf61b3 R12: 1ffff1100eaf61b3 R13: 0000000000000000 R14: ffff8880757b0d98 R15: ffff88807c2c2000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff7e35fb6b0 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400