INFO: task syz.8.1176:9670 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.8.1176 state:D stack:27016 pid:9670 ppid:7606 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 perf_pending_task_sync kernel/events/core.c:5242 [inline] _free_event+0x174/0xf30 kernel/events/core.c:5248 put_event kernel/events/core.c:5376 [inline] perf_event_release_kernel+0x836/0x8c0 kernel/events/core.c:5501 perf_release+0x3b/0x40 kernel/events/core.c:5511 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f334738ebe9 RSP: 002b:00007ffcadbe8ee8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f33475c7da0 RCX: 00007f334738ebe9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f33475c7da0 R08: 0000000000007e84 R09: 00000007adbe91df R10: 00007f33475c7cb0 R11: 0000000000000246 R12: 0000000000054b72 R13: 00007f33475c6090 R14: ffffffffffffffff R15: 00007ffcadbe9000 Showing all locks held in the system: 3 locks held by kworker/u4:0/11: 1 lock held by khungtaskd/29: #0: ffffffff8cd2fc20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fc20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fc20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:3/48: 2 locks held by kworker/u4:4/59: 2 locks held by getty/5549: #0: ffff88802c87a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 2 locks held by syz-executor/5776: 2 locks held by syz.3.1189/9705: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5775 Comm: sshd-session Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__lock_release kernel/locking/lockdep.c:-1 [inline] RIP: 0010:lock_release+0x2a8/0x8b0 kernel/locking/lockdep.c:5774 Code: 00 e0 ff 0f b6 04 33 84 c0 0f 85 a9 04 00 00 45 89 2e 45 85 ff 49 bd 00 00 00 00 00 fc ff df 4c 8b 7c 24 08 0f 85 84 02 00 00 <48> 8b 44 24 20 42 0f b6 04 28 84 c0 0f 85 56 04 00 00 48 8b 04 24 RSP: 0018:ffffc9000444fb80 EFLAGS: 00000083 RAX: 00000000000c00ad RBX: 1ffff1100f6b3ca0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffff88802d9040d8 RDI: ffff88807b59e4e0 RBP: ffffc9000444fc88 R08: ffffffff8e4a912f R09: 1ffffffff1c95225 R10: dffffc0000000000 R11: fffffbfff1c95226 R12: ffff88807b59e4e0 R13: dffffc0000000000 R14: ffff88807b59e500 R15: 1ffff92000889f7c FS: 00007f536ce35300(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffee8619728 CR3: 000000002c25f000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:157 [inline] _raw_spin_unlock_irq+0x16/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x11f5/0x1400 kernel/signal.c:2905 arch_do_signal_or_restart+0x96/0x780 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f536c6b0f60 Code: 48 85 f6 74 15 48 b9 00 00 00 80 01 00 00 00 48 8b 06 48 85 c8 75 33 48 89 f0 48 89 c6 41 ba 08 00 00 00 b8 0e 00 00 00 0f 05 <89> c2 f7 da 3d 00 f0 ff ff b8 00 00 00 00 0f 47 c2 48 83 c4 10 c3 RSP: 002b:00007ffc9a2bbbd8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00005559929d5840 RCX: 00007f536c6b0f60 RDX: 0000000000000000 RSI: 00007ffc9a2bbce0 RDI: 0000000000000002 RBP: 00007ffc9a2bbc50 R08: 000000000000017c R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc9a2bbce0 R14: 0000000000000001 R15: 0000000000000004