------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:1087 at mark_buffer_dirty+0x299/0x410, CPU#1: syz.1.5773/23327
Modules linked in:
CPU: 1 UID: 0 PID: 23327 Comm: syz.1.5773 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:mark_buffer_dirty+0x299/0x410
Code: 4c 89 f7 e8 79 17 da ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 04 64 fb ff e8 ff bf 6e ff eb 8c e8 f8 bf 6e ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 ea bf 6e ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc90005ff7608 EFLAGS: 00010283
RAX: ffffffff8256d808 RBX: ffff8881a75c1740 RCX: 0000000000080000
RDX: ffffc9000b8a1000 RSI: 0000000000001597 RDI: 0000000000001598
RBP: ffff8881af58e001 R08: ffff8881a75c1747 R09: 1ffff11034eb82e8
R10: dffffc0000000000 R11: ffffed1034eb82e9 R12: ffff8881a89ef600
R13: ffff8881a76e3ae0 R14: ffff8881a75c1740 R15: 000000000000000a
FS:  00007fcd99f976c0(0000) GS:ffff8882a9296000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f11d0de72fc CR3: 00000001729dc000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 bfs_get_block+0x5da/0xae0
 __block_write_begin_int+0x6c6/0x1910
 block_write_begin+0x8d/0x120
 bfs_write_begin+0x35/0xd0
 generic_perform_write+0x2e2/0x8f0
 generic_file_write_iter+0x14a/0x680
 vfs_write+0x61d/0xb90
 ksys_write+0x150/0x270
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcd9919cdd9
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:00007fcd99f97028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fcd99415fa0 RCX: 00007fcd9919cdd9
RDX: 000000000000fecc RSI: 00002000000008c0 RDI: 0000000000000007
RBP: 00007fcd99232d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fcd99416038 R14: 00007fcd99415fa0 R15: 00007fff38f09e78
 </TASK>
