INFO: task syz.0.13:5952 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.13 state:D stack:22568 pid:5952 ppid:5825 flags:0x00004006 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 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x90b/0x23c0 kernel/exit.c:883 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 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: 0033:0x7f0419a4f6b0 RSP: 002b:00007f041aa8c238 EFLAGS: 00000283 RAX: 0000000000000000 RBX: 00007f041aa8cd30 RCX: 00007f0419dab120 RDX: 00007f041aa8c240 RSI: 00007f041aa8c370 RDI: 000000000000000b RBP: 000000000000000b R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000000 R12: 0000000000000073 R13: 00007f041aa8ceb0 R14: 9999999999999999 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by rcu_tasks_trace/15: #0: ffff8880b8e3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 1 lock held by khungtaskd/29: #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2fee0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5551: #0: ffff88802c69f0a0 (&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 1 lock held by syz.2.1122/8883: #0: ffffffff8cd8ff68 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0x85/0x310 kernel/trace/bpf_trace.c:2215 2 locks held by syz.1.1124/8888: #0: ffffffff8cd85d68 (event_mutex){+.+.}-{3:3}, at: perf_trace_destroy+0x2e/0x140 kernel/trace/trace_event_perf.c:239 #1: ffffffff8cd358b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #1: ffffffff8cd358b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004 1 lock held by syz.3.1125/8890: #0: ffffffff8cd8ff68 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0x85/0x310 kernel/trace/bpf_trace.c:2215 1 lock held by syz.4.1132/8891: #0: ffffffff8cd8ff68 (bpf_event_mutex){+.+.}-{3:3}, at: perf_event_detach_bpf_prog+0x85/0x310 kernel/trace/bpf_trace.c:2215 ============================================= 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 10/02/2025 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: 5149 Comm: klogd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215 Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 0c 00 c5 0c 48 89 de 5b e9 a3 8a 56 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 20 28 7e 7e 65 8b 15 21 28 7e 7e 81 e2 00 01 ff 00 74 RSP: 0018:ffffc900032a74a8 EFLAGS: 00000287 RAX: ffffffff81acd2c1 RBX: 000000000000002c RCX: 0000000000000000 RDX: ffff88807dca8000 RSI: 000000000000002c RDI: 0000000000002000 RBP: ffffc900032a7610 R08: ffffffff8e4a8d6f R09: 1ffffffff1c951ad R10: dffffc0000000000 R11: fffffbfff1c951ae R12: dffffc0000000000 R13: dffffc0000000000 R14: ffffc900032a7580 R15: ffffc900032a75a0 FS: 00007f76526bfc80(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000001f4c0 CR3: 000000002bb20000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_swevent_get_recursion_context+0x11/0x150 kernel/events/core.c:9944 perf_trace_buf_alloc+0x59/0x290 kernel/trace/trace_event_perf.c:410 perf_trace_lock+0x193/0x380 include/trace/events/lock.h:50 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x857/0x8b0 kernel/locking/lockdep.c:5765 rcu_lock_release include/linux/rcupdate.h:344 [inline] rcu_read_unlock include/linux/rcupdate.h:819 [inline] trace_call_bpf+0x5ae/0x690 kernel/trace/bpf_trace.c:145 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10263 perf_trace_lock+0x2ed/0x380 include/trace/events/lock.h:50 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x857/0x8b0 kernel/locking/lockdep.c:5765 __mutex_unlock_slowpath+0xb7/0x6a0 kernel/locking/mutex.c:907 syslog_print+0x417/0x590 kernel/printk/printk.c:1629 do_syslog+0x576/0x7f0 kernel/printk/printk.c:1732 __do_sys_syslog kernel/printk/printk.c:1824 [inline] __se_sys_syslog kernel/printk/printk.c:1822 [inline] __x64_sys_syslog+0x7c/0x90 kernel/printk/printk.c:1822 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7652889a37 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:00007ffdb5bf9478 EFLAGS: 00000206 ORIG_RAX: 0000000000000067 RAX: ffffffffffffffda RBX: 00007f7652a29490 RCX: 00007f7652889a37 RDX: 00000000000003ff RSI: 00007f7652a29490 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000206 R12: 00007f7652a29490 R13: 00007f7652a06dfe R14: 00007f7652a2987c R15: 00007f7652a2987c