loop0: detected capacity change from 0 to 64
cgroup: name respecified
------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:1093 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:1093, CPU#0: syz.0.0/5323
Modules linked in:
CPU: 0 UID: 0 PID: 5323 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 04/01/2014
RIP: 0010:mark_buffer_dirty+0x299/0x410 fs/buffer.c:1093
Code: 4c 89 f7 e8 39 10 d9 ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 d4 5e fb ff e8 2f ec 69 ff eb 8c e8 28 ec 69 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 1a ec 69 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc9000dc96648 EFLAGS: 00010287
RAX: ffffffff825c9668 RBX: ffff888042b4b380 RCX: 0000000000100000
RDX: ffffc9000ec32000 RSI: 000000000000332f RDI: 0000000000003330
RBP: 0000000000000201 R08: ffff888042b4b387 R09: 1ffff11008569670
R10: dffffc0000000000 R11: ffffed1008569671 R12: 0000000000000013
R13: ffff888042b4b380 R14: ffff88801300ac40 R15: dffffc0000000000
FS:  00007f9b67fb36c0(0000) GS:ffff88808c54e000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2e853b5665 CR3: 0000000012b54000 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+0x5c6/0xb50 fs/bfs/file.c:126
 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2123
 block_write_begin+0x8d/0x120 fs/buffer.c:2234
 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:180
 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4358
 generic_file_write_iter+0xae/0x330 mm/filemap.c:4501
 __kernel_write_iter+0x44a/0x8f0 fs/read_write.c:621
 __kernel_write+0x106/0x170 fs/read_write.c:641
 __dump_emit fs/coredump.c:1220 [inline]
 dump_emit+0x920/0xb00 fs/coredump.c:1258
 elf_core_dump+0x2ff4/0x3a90 fs/binfmt_elf.c:2088
 coredump_write+0x1290/0x1960 fs/coredump.c:1052
 do_coredump fs/coredump.c:1131 [inline]
 vfs_coredump+0x36ff/0x44b0 fs/coredump.c:1200
 get_signal+0x1094/0x12c0 kernel/signal.c:3023
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9b6719de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9b67fb2fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffe5 RBX: 00007f9b67425fa0 RCX: 00007f9b6719de59
RDX: 0000000000000042 RSI: 0000200000000280 RDI: 0000000000000005
RBP: 00007f9b67233e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0006000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9b67426038 R14: 00007f9b67425fa0 R15: 00007fffa3c6ec38
 </TASK>