loop7: detected capacity change from 0 to 64
------------[ cut here ]------------
WARNING: CPU: 0 PID: 19505 at fs/buffer.c:1183 mark_buffer_dirty+0x2a9/0x410 fs/buffer.c:1183
Modules linked in:
CPU: 0 UID: 0 PID: 19505 Comm: syz.7.3153 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:mark_buffer_dirty+0x2a9/0x410 fs/buffer.c:1183
Code: 4c 89 f7 e8 d9 4b dd ff 49 8b 3e be 20 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 d4 02 fc ff e8 9f dd 79 ff eb 8c e8 98 dd 79 ff 90 <0f> 0b 90 e9 95 fd ff ff e8 8a dd 79 ff 90 0f 0b 90 e9 bf fd ff ff
RSP: 0018:ffffc9000445f608 EFLAGS: 00010202
RAX: ffffffff8245cdf8 RBX: ffff888042ce6828 RCX: ffff888034b13c00
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff888028612001 R08: 0000000000000da4 R09: 0000000000400000
R10: 000000000001b488 R11: ffffed100859cd06 R12: ffff88808b151600
R13: ffff8880424f6570 R14: ffff888042ce6828 R15: 000000000000000a
FS:  00007f6a750d26c0(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 00000000453ec000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 bfs_move_block fs/bfs/file.c:44 [inline]
 bfs_move_blocks fs/bfs/file.c:57 [inline]
 bfs_get_block+0x5da/0xae0 fs/bfs/file.c:126
 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
 block_write_begin+0x8a/0x120 fs/buffer.c:2256
 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:180
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175
 generic_file_write_iter+0x117/0x550 mm/filemap.c:4318
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_write+0x145/0x250 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a7418ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6a750d2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6a743b5fa0 RCX: 00007f6a7418ebe9
RDX: 00000000fffffdef RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f6a74211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6a743b6038 R14: 00007f6a743b5fa0 R15: 00007ffee26dd3f8
 </TASK>