INFO: task syz-executor:5847 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21128 pid:5847 tgid:5847 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339 rwbase_write_lock+0x3dd/0x750 kernel/locking/rwbase_rt.c:272 __super_lock fs/super.c:57 [inline] __super_lock_excl fs/super.c:72 [inline] deactivate_super+0xa9/0xe0 fs/super.c:506 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff16b21fed7 RSP: 002b:00007ffc0d07eaf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ff16b2a1c05 RCX: 00007ff16b21fed7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc0d07ebb0 RBP: 00007ffc0d07ebb0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc0d07fc40 R13: 00007ff16b2a1c05 R14: 00000000000221bc R15: 00007ffc0d07fc80 INFO: task syz.2.49:6479 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.49 state:D stack:24680 pid:6479 tgid:6478 ppid:5837 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 f2fs_issue_checkpoint+0x376/0x570 fs/f2fs/checkpoint.c:-1 __iterate_supers+0x13d/0x290 fs/super.c:924 ksys_sync+0xb2/0x150 fs/sync.c:104 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f102d8ceba9 RSP: 002b:00007f102bb36038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f102db15fa0 RCX: 00007f102d8ceba9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f102db15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f102db16038 R14: 00007f102db15fa0 R15: 00007ffdad521b38 Showing all locks held in the system: 6 locks held by kworker/u8:1/13: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:5/161: #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc90003affbc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc90003affbc0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 2 locks held by kworker/u8:7/1408: 6 locks held by kworker/u8:12/4523: 2 locks held by getty/5596: #0: ffff88823bf300a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222 2 locks held by kworker/1:3/5829: 1 lock held by syz-executor/5847: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 5 locks held by udevd/5896: 2 locks held by udevd/5976: #0: ffff88802faae790 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #0: ffff88802faae790 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x214/0x4d0 mm/util.c:578 #1: ffff88803088c168 (&anon_vma->rwsem){++++}-{4:4}, at: anon_vma_lock_read include/linux/rmap.h:137 [inline] #1: ffff88803088c168 (&anon_vma->rwsem){++++}-{4:4}, at: validate_mm+0x1d4/0x4b0 mm/vma.c:679 1 lock held by syz.2.49/6479: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 3 locks held by f2fs_ckpt-7:4/6484: 1 lock held by syz.0.61/6578: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.3.73/6701: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.6.89/6934: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.8.80/7012: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.8.80/7015: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by udevd/7194: #0: ffff888037948250 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:415 [inline] #0: ffff888037948250 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x214/0x4d0 mm/util.c:578 #1: ffff88803088c168 (&anon_vma->rwsem){++++}-{4:4}, at: anon_vma_lock_read include/linux/rmap.h:137 [inline] #1: ffff88803088c168 (&anon_vma->rwsem){++++}-{4:4}, at: validate_mm+0x1d4/0x4b0 mm/vma.c:679 2 locks held by kworker/u8:14/7546: 1 lock held by syz.2.166/7786: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 1 lock held by syz.2.166/7789: #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880272ea0d0 (&type->s_umount_key#55){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz-executor/7954: 2 locks held by syz.5.191/7998: #0: ffff88807d2640d0 (&type->s_umount_key#52/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345 #1: ffffffff8da6eef8 (lock#3){+.+.}-{4:4}, at: __lru_add_drain_all+0x66/0x5e0 mm/swap.c:835 2 locks held by syz.7.190/8001: 2 locks held by syz.9.192/8003: ============================================= NMI backtrace for cpu 0 CPU: 0 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: 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:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5829 Comm: kworker/1:3 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+0x84a/0xd20 kernel/locking/lockdep.c:-1 Code: e2 44 01 f9 41 29 d7 89 d6 c1 c6 06 44 31 fe 01 ca 89 f0 c1 c0 08 29 f1 31 c8 01 d6 29 c2 89 c1 c1 c1 10 31 d1 01 f0 41 89 cf <41> c1 c7 13 29 ce 41 31 f7 01 c1 44 29 f8 44 01 f9 41 c1 c7 04 41 RSP: 0018:ffffc90004d07750 EFLAGS: 00000086 RAX: 00000000fa3d9d88 RBX: 0000000000000002 RCX: 000000001d32bf4b RDX: 000000001a63af1a RSI: 00000000e9ec9637 RDI: ffff888026e61dc0 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8af94440 R10: dffffc0000000000 R11: fffffbfff1e3abe7 R12: 00000000a1dcdc64 R13: ffff888026e628e0 R14: ffff888026e62930 R15: 000000001d32bf4b FS: 0000000000000000(0000) GS:ffff8881269bc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe29cc63000 CR3: 000000002c75c000 CR4: 00000000003526f0 Call Trace: 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 rt_mutex_slowunlock+0xb0/0x8a0 kernel/locking/rtmutex.c:1417 spin_unlock include/linux/spinlock_rt.h:105 [inline] wg_ratelimiter_gc_entries+0x3a8/0x480 drivers/net/wireguard/ratelimiter.c:76 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245