------------[ cut here ]------------
WARNING: CPU: 0 PID: 5360 at fs/buffer.c:1183 mark_buffer_dirty+0x2a9/0x410 fs/buffer.c:1183
Modules linked in:
CPU: 0 UID: 0 PID: 5360 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:mark_buffer_dirty+0x2a9/0x410 fs/buffer.c:1183
Code: 4c 89 f7 e8 f9 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 bf 5b 78 ff eb 8c e8 b8 5b 78 ff 90 <0f> 0b 90 e9 95 fd ff ff e8 aa 5b 78 ff 90 0f 0b 90 e9 bf fd ff ff
RSP: 0018:ffffc9000d40f608 EFLAGS: 00010293
RAX: ffffffff824762d8 RBX: ffff88804373b910 RCX: ffff88803a43a440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff888037b78001 R08: ffff88804373b917 R09: 1ffff110086e7722
R10: dffffc0000000000 R11: ffffed10086e7723 R12: ffff88804cd22000
R13: ffff8880321612b8 R14: ffff88804373b910 R15: 0000000000000010
FS:  00007fb9117ad6c0(0000) GS:ffff88808d20c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000001000 CR3: 000000003f508000 CR4: 0000000000352ef0
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+0x6b2/0x1900 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+0x5c6/0xb30 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: 0033:0x7fb91098ebe9
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:00007fb9117ad038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb910bc6090 RCX: 00007fb91098ebe9
RDX: 000000000000fecc RSI: 0000200000000100 RDI: 0000000000000005
RBP: 00007fb910a11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb910bc6128 R14: 00007fb910bc6090 R15: 00007fff5659b898
 </TASK>