INFO: task syz-executor:9409 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:20504 pid:9409 tgid:9409 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 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:1318 task_work_run+0x1d4/0x260 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:44 [inline] exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6068590a77 RSP: 002b:00007ffebd0539f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f6068613d7d RCX: 00007f6068590a77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffebd053ab0 RBP: 00007ffebd053ab0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffebd054b40 R13: 00007f6068613d7d R14: 000000000008381a R15: 00007ffebd054b80 INFO: task syz.2.2001:14371 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2001 state:D stack:27576 pid:14371 tgid:14368 ppid:5886 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 io_schedule+0x81/0xe0 kernel/sched/core.c:7792 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250 __wait_on_bit_lock+0xe3/0x4c0 kernel/sched/wait_bit.c:93 out_of_line_wait_on_bit_lock+0x123/0x170 kernel/sched/wait_bit.c:120 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline] __lock_buffer fs/buffer.c:71 [inline] lock_buffer include/linux/buffer_head.h:432 [inline] __block_write_full_folio+0x54f/0xe10 fs/buffer.c:1910 blkdev_writepages+0xd1/0x170 block/fops.c:491 do_writepages+0x32e/0x550 mm/page-writeback.c:2598 filemap_writeback mm/filemap.c:386 [inline] filemap_fdatawrite_range mm/filemap.c:411 [inline] filemap_fdatawrite+0x19c/0x240 mm/filemap.c:417 sync_bdevs+0x30a/0x470 block/bdev.c:1317 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa65f9bf749 RSP: 002b:00007fa65dc1e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fa65fc15fa0 RCX: 00007fa65f9bf749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fa65fc15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa65fc16038 R14: 00007fa65fc15fa0 R15: 00007ffecec58e78 INFO: task syz.2.2001:14373 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.2001 state:D stack:27656 pid:14373 tgid:14368 ppid:5886 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1480/0x50a0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 io_schedule+0x81/0xe0 kernel/sched/core.c:7792 folio_wait_bit_common+0x6b5/0xb90 mm/filemap.c:1317 folio_lock include/linux/pagemap.h:1151 [inline] __find_get_block_slow fs/buffer.c:205 [inline] find_get_block_common+0x2e6/0xfc0 fs/buffer.c:1408 bdev_getblk+0x4b/0x660 fs/buffer.c:-1 __bread_gfp+0x89/0x3b0 fs/buffer.c:1515 sb_bread include/linux/buffer_head.h:346 [inline] hfs_mdb_commit+0xc02/0x12e0 fs/hfs/mdb.c:324 hfs_sync_fs+0x15/0x20 fs/hfs/super.c:37 __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/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa65f9bf749 RSP: 002b:00007fa65dbfd038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fa65fc16090 RCX: 00007fa65f9bf749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fa65fc16090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa65fc16128 R14: 00007fa65fc16090 R15: 00007ffecec58e78 Showing all locks held in the system: 2 locks held by ksoftirqd/1/30: 1 lock held by khungtaskd/38: #0: ffffffff8d5aeba0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5aeba0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5aeba0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:2/43: 3 locks held by kworker/u8:9/1139: #0: ffff88801cea2938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801cea2938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc90004777b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90004777b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffff88801b2b00d0 (&type->s_umount_key#41){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 4 locks held by kworker/u8:13/2149: 2 locks held by kworker/u8:14/2222: 2 locks held by getty/5561: #0: ffff88814e05d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 2 locks held by udevd/5992: #0: ffff888022124868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1042 [inline] #0: ffff888022124868 (&sb->s_type->i_mutex_key#8){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:859 #1: ffff888022124a38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1092 [inline] #1: ffff888022124a38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2542 [inline] #1: ffff888022124a38 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x772/0x1ee0 mm/filemap.c:2706 5 locks held by udevd/6009: 1 lock held by udevd/6019: 1 lock held by udevd/6089: 2 locks held by kworker/1:8/6461: #0: ffff88813ff55938 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff55938 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc9000c067b80 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000c067b80 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 4 locks held by udevd/6572: 1 lock held by syz-executor/9409: #0: ffff8880278580d0 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff8880278580d0 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff8880278580d0 (&type->s_umount_key#87){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 1 lock held by syz.2.2001/14371: #0: ffff888143b104c8 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1305 1 lock held by syz.2.2001/14373: #0: ffff8880278580d0 (&type->s_umount_key#87){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff8880278580d0 (&type->s_umount_key#87){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 4 locks held by kworker/1:9/17014: 2 locks held by udevd/17020: 2 locks held by syz.6.2536/18255: #0: ffff8880302380d0 (&type->s_umount_key#65/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344 #1: ffffffff8d212698 (bit_wait_table + i){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #1: ffffffff8d212698 (bit_wait_table + i){+.+.}-{3:3}, at: finish_wait kernel/sched/wait.c:394 [inline] #1: ffffffff8d212698 (bit_wait_table + i){+.+.}-{3:3}, at: __wait_on_bit+0x1ff/0x300 kernel/sched/wait_bit.c:55 4 locks held by syz.0.2546/18294: 4 locks held by syz.8.2547/18296: 2 locks held by syz.3.2548/18324: ============================================= 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 10/25/2025 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:332 [inline] watchdog+0xf3c/0xf80 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 17014 Comm: kworker/1:9 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_power_efficient wg_ratelimiter_gc_entries RIP: 0010:match_held_lock+0x0/0xb0 kernel/locking/lockdep.c:5305 Code: c3 cc cc cc cc cc e8 5f f9 ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <41> 56 53 bb 01 00 00 00 48 39 77 10 74 6a 81 7f 20 00 00 20 00 72 RSP: 0018:ffffc90003ac75f0 EFLAGS: 00000083 RAX: 0000000000000004 RBX: ffff8880257f29f8 RCX: b428379466c44a00 RDX: dffffc0000000000 RSI: ffffffff8dfea2b8 RDI: ffff8880257f29f8 RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000758f00 R12: 0000000000000046 R13: ffff8880257f1e40 R14: ffffffff8dfea2b8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888126e5a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f57a4d6fffc CR3: 000000005def8000 CR4: 00000000003526f0 Call Trace: __lock_is_held kernel/locking/lockdep.c:5601 [inline] lock_is_held_type+0xa8/0x190 kernel/locking/lockdep.c:5940 lock_is_held include/linux/lockdep.h:249 [inline] try_to_take_rt_mutex+0x4f/0xb00 kernel/locking/rtmutex.c:1090 rtlock_slowlock_locked+0xd8/0x4010 kernel/locking/rtmutex.c:1839 rtlock_slowlock kernel/locking/rtmutex.c:1895 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x158/0x3e0 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:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246