[v5.15] INFO: task hung in xfs_file_buffered_write

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: c52b9710c83d Linux 5.15.156
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14195ed8980000
kernel config: https://syzkaller.appspot.com/x/.config?x=567b6ddc38438433
dashboard link: https://syzkaller.appspot.com/bug?extid=60d80a36b908311934a3
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1bd4b9969373/disk-c52b9710.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/10509e89bd25/vmlinux-c52b9710.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a623a4c52eb5/bzImage-c52b9710.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+60d80a...@syzkaller.appspotmail.com

INFO: task syz-executor.1:4768 blocked for more than 143 seconds.
Not tainted 5.15.156-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1 state:D stack:21912 pid: 4768 ppid: 3523 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
schedule_timeout+0xac/0x300 kernel/time/timer.c:1890
do_wait_for_common+0x2d9/0x480 kernel/sched/completion.c:85
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x48/0x60 kernel/sched/completion.c:138
__flush_work+0x124/0x1a0 kernel/workqueue.c:3094
xfs_file_buffered_write+0x40e/0xb20 fs/xfs/xfs_file.c:777
__kernel_write+0x5b1/0xa60 fs/read_write.c:539
__dump_emit+0x264/0x3a0 fs/coredump.c:875
dump_user_range+0x91/0x320 fs/coredump.c:949
elf_core_dump+0x3c7d/0x4570 fs/binfmt_elf.c:2285
do_coredump+0x1852/0x31e0 fs/coredump.c:826
get_signal+0xc06/0x14e0 kernel/signal.c:2875
arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f57d3044ea9
RSP: 002b:00007f57d15b70c8 EFLAGS: 00000246
ORIG_RAX: 000000000000011d
RAX: ffffffffffffffe5 RBX: 00007f57d3172f80 RCX: 00007f57d3044ea9
RDX: 0000020000000004 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f57d30914a4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000081 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f57d3172f80 R15: 00007ffeca75f688
</TASK>
INFO: task kworker/1:22:4803 blocked for more than 144 seconds.
Not tainted 5.15.156-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:22 state:D
stack:25656 pid: 4803 ppid: 2 flags:0x00004000
Workqueue: xfs-sync/loop1 xfs_flush_inodes_worker

Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191
sync_inodes_sb+0x293/0xab0 fs/fs-writeback.c:2770
xfs_flush_inodes_worker+0x5d/0x80 fs/xfs/xfs_super.c:589
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/26:
#0: ffffffff8c91fb20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:2/154:
#0: ffff888142985138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
#1: ffffc900010cfd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
#2: ffff88805fa86650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x20f/0x1180 fs/xfs/libxfs/xfs_bmap.c:4573
#3: ffff88806fdaf8e8 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x23c/0x1180 fs/xfs/libxfs/xfs_bmap.c:4578
2 locks held by getty/3261:
#0: ffff88814b57a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc9000209b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
5 locks held by kworker/0:10/4487:
2 locks held by syz-executor.1/4768:
#0: ffff88805fa86460 (sb_writers#14){.+.+}-{0:0}, at: do_coredump+0x1825/0x31e0 fs/coredump.c:825
#1: ffff88806fdafb00 (&sb->s_type->i_mutex_key#22){++++}-{3:3}, at: xfs_ilock+0xec/0x390 fs/xfs/xfs_inode.c:184
4 locks held by kworker/1:22/4803:
#0:
ffff88805eb93138
(
(wq_completion)xfs-sync/loop1
){+.+.}-{0:0}
, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
#1:
ffffc90003a07d20
(
(work_completion)(&mp->m_flush_inodes_work)
){+.+.}-{0:0}
, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
#2:
ffff88805fa860e0
(
&type->s_umount_key
#52
){++++}-{3:3}
, at: xfs_flush_inodes_worker+0x41/0x80 fs/xfs/xfs_super.c:588
#3:
ffff8881472147d8
(
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768
2 locks held by syz-executor.2/6715:
#0:
ffff88805fa860e0
(
&type->s_umount_key
#52
){++++}-{3:3}
, at: iterate_supers+0xac/0x1e0 fs/super.c:703
#1:
ffff8881472147d8
(
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x274/0xab0 fs/fs-writeback.c:2768

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 26 Comm: khungtaskd Not tainted 5.15.156-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
watchdog+0xe72/0xeb0 kernel/hung_task.c:295
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4487 Comm: kworker/0:10 Not tainted 5.15.156-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: xfs-buf/loop1 xfs_buf_ioend_work
RIP: 0010:put_dec_trunc8+0x4a/0x330 lib/vsprintf.c:229
Code: 00 00 00 89 ee e8 e6 09 52 fd 83 fd 63 77 0a e8 7c 06 52 fd e9 7b 01 00 00 89 e8 4c 69 e0 29 5c 8f 02 49 c1 ec 20 41 6b dc 9c <01> eb bf 64 00 00 00 89 de e8 b8 09 52 fd 83 fb 63 0f 87 7e 02 00
RSP: 0018:ffffc90003e471e8 EFLAGS: 00000282
RAX: 00000000000000f4 RBX: 00000000ffffff38 RCX: ffff8880234ed940
RDX: ffff8880234ed940 RSI: 00000000000000f4 RDI: 0000000000000064
RBP: 00000000000000f4 R08: ffffffff842e565a R09: ffffc90003e472a0
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000002
R13: dffffc0000000000 R14: ffffc90003e472a0 R15: ffffc90003e476a1
FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557552ee3030 CR3: 000000007528c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
number+0x333/0xf80 lib/vsprintf.c:507
vsnprintf+0x12b6/0x1c70 lib/vsprintf.c:2877
sprintf+0xd6/0x120 lib/vsprintf.c:3013
print_time kernel/printk/printk.c:1274 [inline]
info_print_prefix+0x167/0x300 kernel/printk/printk.c:1300
record_print_text kernel/printk/printk.c:1349 [inline]
console_unlock+0x7c1/0x12b0 kernel/printk/printk.c:2725
vprintk_emit+0xbf/0x150 kernel/printk/printk.c:2274
_printk+0xd1/0x120 kernel/printk/printk.c:2299
__xfs_printk fs/xfs/xfs_message.c:24 [inline]
xfs_alert+0x1c8/0x320 fs/xfs/xfs_message.c:52
xfs_buf_verifier_error+0x1b0/0x290 fs/xfs/xfs_error.c:416
xfs_agfl_read_verify+0x1e3/0x290 fs/xfs/libxfs/xfs_alloc.c:645
xfs_buf_ioend+0x26a/0x6e0 fs/xfs/xfs_buf.c:1263
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>


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