syzbot


INFO: task hung in perf_event_free_task

Status: auto-obsoleted due to no activity on 2024/02/09 23:23
Reported-by: syzbot+916405b348f5c1ad3403@syzkaller.appspotmail.com
First crash: 374d, last: 374d
Fix bisection: failed (error log, bisect log)
  
Bug presence (1)
Date Name Commit Repro Result
2023/11/02 upstream (ToT) 90d624af2e5a C Didn't crash
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in perf_event_free_task (3) 3 921d 1067d 0/1 auto-obsoleted due to no activity on 2022/08/31 14:29
linux-4.19 INFO: task hung in perf_event_free_task (2) 2 1277d 1349d 0/1 auto-closed as invalid on 2021/09/09 09:13
linux-4.19 INFO: task hung in perf_event_free_task (4) 4 620d 789d 0/1 upstream: reported on 2022/09/12 12:14
upstream INFO: task hung in perf_event_free_task perf C done error 40 426d 1935d 0/28 auto-obsoleted due to no activity on 2023/12/19 10:14
linux-5.15 INFO: task hung in perf_event_free_task (2) 1 260d 260d 0/3 auto-obsoleted due to no activity on 2024/06/02 07:34
linux-6.1 INFO: task hung in perf_event_free_task origin:upstream missing-backport C unreliable 3 320d 424d 0/3 upstream: reported C repro on 2023/09/12 07:14
linux-4.19 INFO: task hung in perf_event_free_task 5 1492d 1887d 0/1 auto-closed as invalid on 2021/02/06 21:15
upstream INFO: task can't die in perf_event_free_task perf syz unreliable 6 751d 1451d 0/28 auto-obsoleted due to no activity on 2023/04/21 23:56

Sample crash report:
INFO: task syz-executor926:5913 blocked for more than 143 seconds.
      Not tainted 5.15.137-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor926 state:D stack:26624 pid: 5913 ppid:  3532 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5026 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6372
 schedule+0x11b/0x1f0 kernel/sched/core.c:6455
 perf_event_free_task+0x555/0x680 kernel/events/core.c:13084
 copy_process+0x303a/0x3ef0 kernel/fork.c:2485
 kernel_clone+0x210/0x960 kernel/fork.c:2604
 __do_sys_clone kernel/fork.c:2721 [inline]
 __se_sys_clone kernel/fork.c:2705 [inline]
 __x64_sys_clone+0x23f/0x290 kernel/fork.c:2705
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fca9a2dacf9
RSP: 002b:00007fca99a98228 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007fca9a2dacf9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000d816e480
RBP: 00007fca9a3653c8 R08: 0000000000000000 R09: 00007fca99a986c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fca9a3653c0
R13: 00000000d816e480 R14: 00000000d816e480 R15: 00007fffb2782428
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91f020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by klogd/2951:
 #0: ffff8880b9b39718 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475
2 locks held by getty/3263:
 #0: ffff8880250ea098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002bb32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.137-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:109 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:570

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/11/01 23:22 linux-5.15.y 12952a23a5da 69904c9f .config console log report syz C ci2-linux-5-15-kasan-perf INFO: task hung in perf_event_free_task
* Struck through repros no longer work on HEAD.