------------[ cut here ]------------
!buffer_uptodate(bh)
WARNING: fs/buffer.c:1093 at mark_buffer_dirty+0x299/0x410 fs/buffer.c:1093, CPU#0: kworker/u4:4/68
Modules linked in:
CPU: 0 UID: 0 PID: 68 Comm: kworker/u4:4 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
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:mark_buffer_dirty+0x299/0x410 fs/buffer.c:1093
Code: 4c 89 f7 e8 c9 11 d9 ff 49 8b 3e be 40 00 00 00 5b 41 5c 41 5e 41 5f 5d e9 d4 5e fb ff e8 8f f3 69 ff eb 8c e8 88 f3 69 ff 90 <0f> 0b 90 e9 a5 fd ff ff e8 7a f3 69 ff 90 0f 0b 90 e9 cf fd ff ff
RSP: 0018:ffffc90000aef220 EFLAGS: 00010293
RAX: ffffffff825c8e48 RBX: ffff8880442f7460 RCX: ffff888000a74a80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: 0000000000000001 R08: ffff8880442f7467 R09: 1ffff1100885ee8c
R10: dffffc0000000000 R11: ffffed100885ee8d R12: ffff88801fde124c
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880442f7460
FS: 0000000000000000(0000) GS:ffff88808c818000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b57832230 CR3: 0000000012715000 CR4: 0000000000352ef0
Call Trace:
<TASK>
bfs_write_inode+0x4f0/0x840 fs/bfs/inode.c:167
write_inode fs/fs-writeback.c:1607 [inline]
__writeback_single_inode+0x6ac/0xf90 fs/fs-writeback.c:1850
writeback_sb_inodes+0x9de/0x1b00 fs/fs-writeback.c:2079
__writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2155
wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2266
wb_check_start_all fs/fs-writeback.c:2392 [inline]
wb_do_writeback fs/fs-writeback.c:2439 [inline]
wb_workfn+0x980/0x10f0 fs/fs-writeback.c:2477
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>