------------[ cut here ]------------ kernel BUG at fs/buffer.c:2666! Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 5582 Comm: kmmpd-loop0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/03/2025 pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) pc : submit_bh_wbc+0x3e0/0x454 fs/buffer.c:2666 lr : submit_bh_wbc+0x3e0/0x454 fs/buffer.c:2666 sp : ffff800020f77bb0 x29: ffff800020f77bc0 x28: ffff0000e313a408 x27: dfff800000000000 x26: 1fffe000192bd0cf x25: 0000000000000000 x24: 1fffe0001c07235c x23: dfff800000000000 x22: ffff0000c95ea000 x21: 0000000000003801 x20: ffff0000e0391ae0 x19: 0000000000000005 x18: ffff800011abbcc0 x17: 1fffe00033ed797e x16: ffff8000082d10fc x15: ffff8000150bd000 x14: 0000000000000000 x13: 1ffff00002a180b1 x12: 0000000000ff0100 x11: ff00800008a82a58 x10: 0000000000000000 x9 : ffff800008a82a58 x8 : ffff0000f6d39bc0 x7 : ffff800008db6ac8 x6 : 0000000000000000 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff800008db6298 x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: submit_bh_wbc+0x3e0/0x454 fs/buffer.c:2666 submit_bh+0x2c/0x3c fs/buffer.c:2707 write_mmp_block_thawed+0x300/0x4ac fs/ext4/mmp.c:51 write_mmp_block+0x1e4/0x5f0 fs/ext4/mmp.c:67 kmmpd+0x668/0x940 fs/ext4/mmp.c:246 kthread+0x250/0x2d8 kernel/kthread.c:376 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:850 Code: 17ffffad 97e87c8d d4210000 97e87c8b (d4210000) ---[ end trace 0000000000000000 ]---