syzbot

INFO: task kworker/0:1H:263 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:1H    state:D stack:27328 pid:  263 ppid:     2 flags:0x00004000
Workqueue: glock_workqueue glock_work_func
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 rwsem_down_write_slowpath+0xc46/0x11f0 kernel/locking/rwsem.c:1165
 freeze_super+0x44/0x420 fs/super.c:1696
 freeze_go_sync+0x179/0x340 fs/gfs2/glops.c:587
 do_xmote+0x387/0x1120 fs/gfs2/glock.c:742
 glock_work_func+0x25e/0x470 fs/gfs2/glock.c:1039
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
INFO: task syz.0.17:4435 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:24208 pid: 4435 ppid:  4348 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x97/0x280 kernel/time/timer.c:1890
 do_wait_for_common+0x29a/0x440 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_workqueue+0x63a/0x1380 kernel/workqueue.c:2882
 gfs2_gl_hash_clear+0xbf/0x2f0 fs/gfs2/glock.c:2182
 gfs2_fill_super+0x167d/0x1f50 fs/gfs2/ops_fstype.c:1309
 get_tree_bdev+0x3f1/0x610 fs/super.c:1325
 gfs2_get_tree+0x4d/0x1e0 fs/gfs2/ops_fstype.c:1332
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3034
 do_mount fs/namespace.c:3377 [inline]
 __do_sys_mount fs/namespace.c:3585 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3562
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe2ad7bbeea
RSP: 002b:00007ffda8531438 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffda85314c0 RCX: 00007fe2ad7bbeea
RDX: 00002000000124c0 RSI: 0000200000012500 RDI: 00007ffda8531480
RBP: 00002000000124c0 R08: 00007ffda85314c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000012500
R13: 00007ffda8531480 R14: 00000000000125ad R15: 0000200000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
3 locks held by kworker/0:1H/263:
 #0: ffff888140f91d38 ((wq_completion)glock_workqueue){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000257fd00 ((work_completion)(&(&gl->gl_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffff88805d4300e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: freeze_super+0x44/0x420 fs/super.c:1696
1 lock held by klogd/3550:
 #0: ffff8880b913a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by getty/3947:
 #0: ffff88802c679098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
1 lock held by syz.0.17/4435:
 #0: ffff88805d4300e0 (&type->s_umount_key#53/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.1.215/4741:
 #0: ffff888147681468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4289 Comm: kworker/0:7 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:lock_acquire+0x5d/0x3f0 kernel/locking/lockdep.c:5591
Code: 04 25 28 00 00 00 48 89 84 24 c0 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 c7 44 24 60 b3 8a b5 41 48 c7 44 24 68 cc 5c 9b 8b <48> c7 44 24 70 f0 f9 5b 81 4c 8d 6c 24 60 49 c1 ed 03 48 b8 f1 f1
RSP: 0018:ffffc9000308faa0 EFLAGS: 00000286
RAX: 90175e9c84fb4100 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8ca60978
RBP: ffffc9000308fbc0 R08: 0000000000000001 R09: 0000000000000000
R10: fffffbfff194c12d R11: 1ffffffff194c12c R12: ffffffff8ca60978
R13: ffff8880249eca18 R14: 0000000000001070 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555568258608 CR3: 000000002a9b3000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:364 [inline]
 wg_ratelimiter_gc_entries+0x59/0x450 drivers/net/wireguard/ratelimiter.c:63
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>