INFO: task syz.0.41:6705 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.41 state:D stack:27096 pid:6705 tgid:6704 ppid:6498 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x145f/0x5070 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] rt_mutex_slowlock+0x2a8/0x6b0 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline] mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:552 bdev_release+0x1af/0x660 block/bdev.c:1145 blkdev_release+0x15/0x20 block/fops.c:706 __fput+0x45b/0xa80 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 get_signal+0x11c4/0x1310 kernel/signal.c:2807 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4e0 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+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f617a1bf749 RSP: 002b:00007f6179826038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 00007f617a415fa0 RCX: 00007f617a1bf749 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00007f617a243f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f617a416038 R14: 00007f617a415fa0 R15: 00007ffc0ad59228 Showing all locks held in the system: 7 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/38: #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:15/3090: 7 locks held by kworker/u8:16/3488: 2 locks held by getty/5560: #0: ffff88803506d0a0 (&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+0x44f/0x1460 drivers/tty/n_tty.c:2211 1 lock held by udevd/6464: #0: ffff888024aec4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by udevd/6501: #0: ffff8880249664c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by syz.0.41/6705: #0: ffff8880249664c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1af/0x660 block/bdev.c:1145 1 lock held by udevd/6735: #0: ffff88802497e4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by syz.1.48/6746: #0: ffff88802497e4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1af/0x660 block/bdev.c:1145 1 lock held by syz.2.49/6768: #0: ffff888024aec4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1af/0x660 block/bdev.c:1145 1 lock held by udevd/6793: #0: ffff888024a964c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by syz.3.62/6818: #0: ffff888024a964c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1af/0x660 block/bdev.c:1145 1 lock held by udevd/6858: #0: ffff888024b1e4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by syz.4.68/6867: #0: ffff888024b1e4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1af/0x660 block/bdev.c:1145 1 lock held by udevd/6897: #0: ffff8880250244c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xcc0 block/bdev.c:962 1 lock held by syz.5.137/7063: #0: ffff8880250244c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1af/0x660 block/bdev.c:1145 ============================================= 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 10/25/2025 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3488 Comm: kworker/u8:16 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:mark_lock+0x15/0x190 kernel/locking/lockdep.c:4722 Code: 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 8b 46 20 89 c1 81 e1 00 00 03 00 <83> f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45 da bd 01 00 00 00 RSP: 0018:ffffc9000d49f428 EFLAGS: 00000006 RAX: 000000000002000b RBX: ffff888031540c78 RCX: 0000000000020000 RDX: 0000000000000008 RSI: ffff888031540c58 RDI: ffff888031540000 RBP: ffff888031540c58 R08: ffffffff820eaa79 R09: ffffffff8d5ae940 R10: dffffc0000000000 R11: fffff94000010b59 R12: 0000000000000004 R13: ffff888031540c58 R14: ffff888031540000 R15: 0000000000000005 FS: 0000000000000000(0000) GS:ffff888126cec000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555871e75c8 CR3: 000000000d3a8000 CR4: 00000000003526f0 Call Trace: mark_usage kernel/locking/lockdep.c:4674 [inline] __lock_acquire+0x6b6/0x2cf0 kernel/locking/lockdep.c:5191 lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] ___pte_offset_map+0x45/0x200 mm/pgtable-generic.c:288 __pte_offset_map include/linux/mm.h:3346 [inline] __pte_offset_map_lock+0x46/0x210 mm/pgtable-generic.c:399 get_locked_pte include/linux/mm.h:2984 [inline] __text_poke+0x2cf/0x990 arch/x86/kernel/alternative.c:2525 text_poke arch/x86/kernel/alternative.c:2610 [inline] smp_text_poke_batch_finish+0xd0f/0x1130 arch/x86/kernel/alternative.c:2999 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:874 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+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246