------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:1087 at mark_buffer_dirty+0x299/0x410, CPU#0: syz.1.2070/22849
Modules linked in:
CPU: 0 UID: 0 PID: 22849 Comm: syz.1.2070 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 59 50 da ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 b4 63 fb ff e8 3f f3 6e ff eb 8c e8 38 f3 6e ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 2a f3 6e ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc900077063e8 EFLAGS: 00010293
RAX: ffffffff8256ce98 RBX: ffff888120b53488 RCX: ffff88810369d880
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff88816dc44001 R08: ffff888120b5348f R09: 1ffff1102416a691
R10: dffffc0000000000 R11: ffffed102416a692 R12: ffff8881ab6a5000
R13: ffff88801fba2658 R14: ffff888120b53488 R15: 0000000000000011
FS:  00007f50b95ce6c0(0000) GS:ffff88818dc8c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557401a4a0 CR3: 000000003c61a000 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
 __kernel_write_iter+0x41e/0x880
 __kernel_write+0x106/0x170
 dump_emit+0x8e9/0xab0
 elf_core_dump+0x2e5d/0x3ad0
 coredump_write+0x1216/0x1910
 vfs_coredump+0x3807/0x4530
 get_signal+0x1107/0x1330
 arch_do_signal_or_restart+0xbc/0x840
 irqentry_exit+0x289/0x760
 asm_exc_page_fault+0x26/0x30
RIP: 0033:0x7f50b879cde1
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f50b8a16090 RCX: 00007f50b879cdd9
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007f50b8832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f50b8a16128 R14: 00007f50b8a16090 R15: 00007ffffc2906e8
 </TASK>
