[syzbot] [xfs?] INFO: task hung in xlog_force_lsn (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 971199ad2a0f Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13a5e1e2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=5dad7c03514bf787
dashboard link: https://syzkaller.appspot.com/bug?extid=c27dee924f3271489c82
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17be6304580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10c431e2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6f70cc00930c/disk-971199ad.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/5c5740d1a0de/vmlinux-971199ad.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9f306c159d19/bzImage-971199ad.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/4027534f1a29/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=1495f92f980000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c27dee...@syzkaller.appspotmail.com

INFO: task syz.0.17:6151 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:23560 pid:6151 tgid:6150 ppid:5941 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
xlog_wait fs/xfs/xfs_log_priv.h:588 [inline]
xlog_wait_on_iclog+0x4ac/0x6f0 fs/xfs/xfs_log.c:841
xlog_force_lsn+0x4d7/0x970 fs/xfs/xfs_log.c:3045
xfs_log_force_seq+0x1c9/0x440 fs/xfs/xfs_log.c:3082
__xfs_trans_commit+0x7d2/0xbd0 fs/xfs/xfs_trans.c:879
xfs_trans_commit+0x13e/0x1c0 fs/xfs/xfs_trans.c:928
xfs_sync_sb_buf+0x134/0x230 fs/xfs/libxfs/xfs_sb.c:1472
xfs_ioc_setlabel fs/xfs/xfs_ioctl.c:1039 [inline]
xfs_file_ioctl+0x14b2/0x1830 fs/xfs/xfs_ioctl.c:1196
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f601931eec9
RSP: 002b:00007f6018986038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f6019575fa0 RCX: 00007f601931eec9
RDX: 00002000000001c0 RSI: 0000000041009432 RDI: 0000000000000004
RBP: 00007f60193a1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6019576038 R14: 00007f6019575fa0 R15: 00007fffb9cf9fe8
</TASK>
INFO: task syz.0.17:6177 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.17 state:D stack:27208 pid:6177 tgid:6150 ppid:5941 task_flags:0x400140 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
___down_common kernel/locking/semaphore.c:268 [inline]
__down_common+0x319/0x6a0 kernel/locking/semaphore.c:293
down+0x80/0xd0 kernel/locking/semaphore.c:100
xfs_buf_lock+0x15d/0x4d0 fs/xfs/xfs_buf.c:993
xfs_buf_item_unpin+0x1d4/0x700 fs/xfs/xfs_buf_item.c:556
xlog_cil_ail_insert fs/xfs/xfs_log_cil.c:-1 [inline]
xlog_cil_committed+0x95c/0x1040 fs/xfs/xfs_log_cil.c:897
xlog_cil_process_committed+0x15c/0x1b0 fs/xfs/xfs_log_cil.c:927
xlog_state_shutdown_callbacks+0x269/0x360 fs/xfs/xfs_log.c:488
xlog_force_shutdown+0x332/0x400 fs/xfs/xfs_log.c:3520
xfs_do_force_shutdown+0x283/0x640 fs/xfs/xfs_fsops.c:517
xfs_fs_goingdown+0x71/0x150 fs/xfs/xfs_fsops.c:-1
xfs_file_ioctl+0x11be/0x1830 fs/xfs/xfs_ioctl.c:1371
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f601931eec9
RSP: 002b:00007f6018965038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f6019576090 RCX: 00007f601931eec9
RDX: 0000200000000080 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007f60193a1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6019576128 R14: 00007f6019576090 R15: 00007fffb9cf9fe8
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d7aa500 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/1:1/44:
#0: ffff88805b739138 ((wq_completion)xfs-sync/loop6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88805b739138 ((wq_completion)xfs-sync/loop6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90000b57ba0 ((work_completion)(&(&log->l_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90000b57ba0 ((work_completion)(&(&log->l_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
2 locks held by kworker/u8:4/70:
#0: ffff888055624138 ((wq_completion)xfs-cil/loop6){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888055624138 ((wq_completion)xfs-cil/loop6){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000155fba0 ((work_completion)(&ctx->push_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000155fba0 ((work_completion)(&ctx->push_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
3 locks held by kworker/0:2/1245:
2 locks held by getty/5563:
#0: ffff88823bf320a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz.0.17/6151:
#0: ffff888029a28480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.2.33/6264:
#0: ffff888050c54480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.1.34/6276:
#0: ffff8880551d2480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.3.80/6795:
#0: ffff888056592480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.6.61/6859:
#0: ffff888039de8480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.5.113/7166:
#0: ffff8880365f0480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.4.127/7342:
#0: ffff88802bb78480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.8.104/7367:
#0: ffff888039d14480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.7.171/7768:
#0: ffff888067dbc480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
1 lock held by syz.9.185/7887:
#0: ffff88806ddf0480 (sb_writers#12){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:552
4 locks held by syz.2.319/8216:
1 lock held by syz.6.321/8222:
5 locks held by syz.0.323/8224:
1 lock held by syz-executor/8227:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4b9/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 1245 Comm: kworker/0:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:__lock_acquire+0x818/0xd20 kernel/locking/lockdep.c:-1
Code: 8d 48 89 de e8 d9 b7 1c 03 eb c2 44 89 e0 25 ff 1f 00 00 41 c1 ec 03 41 81 e4 00 60 00 00 41 09 c4 4c 89 f9 48 c1 e9 20 89 ca <c1> c2 04 41 29 cc 44 31 e2 44 01 f9 41 29 d7 89 d6 c1 c6 06 44 31
RSP: 0000:ffffc90005177770 EFLAGS: 00000803
RAX: 0000000000000b53 RBX: 0000000000000003 RCX: 000000008c3c8419
RDX: 000000008c3c8419 RSI: ffff888026bd47d8 RDI: ffff888026bd3c00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ac7bb0a
R10: dffffc0000000000 R11: fffffbfff1deecaf R12: 0000000000000b53
R13: ffff888026bd4760 R14: ffff888026bd47d8 R15: 8c3c8419ff0f723d
FS: 0000000000000000(0000) GS:ffff888126bcd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4515835613 CR3: 0000000071142000 CR4: 00000000003526f0
Call Trace:
<TASK>
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline]
rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
__rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
rt_spin_lock+0x14a/0x3e0 kernel/locking/spinlock_rt.c:57
spin_lock include/linux/spinlock_rt.h:44 [inline]
wg_ratelimiter_gc_entries+0x5d/0x480 drivers/net/wireguard/ratelimiter.c:63
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4b9/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>


---
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