INFO: task syz.1.302:7352 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.302 state:D stack:27240 pid:7352 tgid:7327 ppid:5822 task_flags:0x400740 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x3c0/0x690 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x9c7/0x4280 fs/coredump.c:1197 get_signal+0x1107/0x1330 kernel/signal.c:3019 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __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 include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7b38d9bf79 RSP: 002b:00007f7b39c460e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 00000000000000ca RBX: 00007f7b39016278 RCX: 00007f7b38d9bf79 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f7b3901627c RBP: 00007f7b39016270 R08: 3fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7b39016308 R14: 00007ffd648de910 R15: 00007ffd648de9f8 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5584: #0: ffff8880373a80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5879: 3 locks held by syz.0.874/9989: 1 lock held by syz.4.876/9993: #0: ffffffff8e766440 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 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: 502 Comm: kworker/u8:7 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:check_preemption_disabled+0x14/0xe0 lib/smp_processor_id.c:16 Code: 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 57 f3 6d 07 65 8b 0d 4c f3 6d 07 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d c3 cc cc cc cc cc 9c 59 RSP: 0018:ffffc90003317700 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000002 RDX: 00002aaaaaaac000 RSI: ffffffff8bc9f7c0 RDI: ffffffff8c27ab00 RBP: 000000000000000c R08: 0000000000000000 R09: 1ffffffff1d10f7a R10: dffffc0000000000 R11: fffffbfff1d10f7b R12: dffffc0000000000 R13: ffff88801b098c40 R14: 00002aaaaaaac000 R15: 00002aaaaaaab000 FS: 0000000000000000(0000) GS:ffff888125560000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffef6e40fc0 CR3: 000000000e54c000 CR4: 00000000003526f0 Call Trace: flush_tlb_mm_range+0x36/0x10c0 arch/x86/mm/tlb.c:1454 __text_poke+0x70b/0x9a0 arch/x86/kernel/alternative.c:2608 text_poke arch/x86/kernel/alternative.c:2645 [inline] smp_text_poke_batch_finish+0xd36/0x1160 arch/x86/kernel/alternative.c:3034 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1fe/0x290 mm/kfence/core.c:906 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245