INFO: task syz.2.513:5584 blocked for more than 143 seconds. Not tainted 6.1.146-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.513 state:D stack:25440 pid:5584 ppid:4280 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x171/0x10a0 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 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:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7f8038e9a9 RSP: 002b:00007ffd8dbf4f88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f7f805b7ba0 RCX: 00007f7f8038e9a9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f7f805b7ba0 R08: 000000000000a040 R09: 000000068dbf527f R10: 00000000005f407c R11: 0000000000000246 R12: 0000000000025aa4 R13: 00007f7f805b6160 R14: ffffffffffffffff R15: 00007ffd8dbf50a0 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b7b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bfd0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4032: #0: ffff88814d7a2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.1.146-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/19/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3627 Comm: klogd Not tainted 6.1.146-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/19/2025 RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:-1 [inline] RIP: 0010:rcu_is_watching+0x40/0xa0 kernel/rcu/tree.c:721 Code: 73 60 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 80 09 5e 8c 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 80 dc 65 00 <48> c7 c3 a8 57 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 RSP: 0018:ffffc90003257a00 EFLAGS: 00000246 RAX: 1ffffffff18bc130 RBX: 0000000000000000 RCX: 545a811821d57400 RDX: 0000000000000000 RSI: ffffffff8adef240 RDI: ffffffff8adef200 RBP: ffffc90003257b40 R08: dffffc0000000000 R09: fffffbfff1c3e91e R10: fffffbfff1c3e91e R11: 1ffffffff1c3e91d R12: 0000000000000000 R13: 1ffff9200064af50 R14: ffffffff8c5e0980 R15: dffffc0000000000 FS: 00007f4705b68c80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055f1d7f2b660 CR3: 0000000031306000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xe8/0x490 kernel/locking/lockdep.c:5633 __might_fault+0xc2/0x120 mm/memory.c:5852 _copy_to_user+0x27/0x130 lib/usercopy.c:36 copy_to_user include/linux/uaccess.h:169 [inline] syslog_print+0x456/0x590 kernel/printk/printk.c:1577 do_syslog+0x7bd/0x8b0 kernel/printk/printk.c:1679 __do_sys_syslog kernel/printk/printk.c:1771 [inline] __se_sys_syslog kernel/printk/printk.c:1769 [inline] __x64_sys_syslog+0x78/0x90 kernel/printk/printk.c:1769 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4705d32a37 Code: 73 01 c3 48 8b 0d c1 f3 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 67 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 f3 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd6fd51a38 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f4705ed2490 RCX: 00007f4705d32a37 RDX: 00000000000003ff RSI: 00007f4705ed2490 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f4705ed2490 R13: 00007f4705eafdfe R14: 00007f4705ed250e R15: 00007f4705ed250e