syzbot


INFO: task hung in perf_event_free_task (2)

Status: auto-obsoleted due to no activity on 2024/06/02 07:34
Reported-by: syzbot+2963f64fe6a71669b684@syzkaller.appspotmail.com
First crash: 292d, last: 292d
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 953d 1099d 0/1 auto-obsoleted due to no activity on 2022/08/31 14:29
linux-5.15 INFO: task hung in perf_event_free_task C error 1 406d 406d 0/3 auto-obsoleted due to no activity on 2024/02/09 23:23
linux-4.19 INFO: task hung in perf_event_free_task (2) 2 1309d 1381d 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 651d 821d 0/1 upstream: reported on 2022/09/12 12:14
upstream INFO: task hung in perf_event_free_task perf C done error 40 458d 1967d 0/28 auto-obsoleted due to no activity on 2023/12/19 10:14
linux-6.1 INFO: task hung in perf_event_free_task origin:upstream missing-backport C unreliable 3 352d 456d 0/3 upstream: reported C repro on 2023/09/12 07:14
linux-4.19 INFO: task hung in perf_event_free_task 5 1524d 1919d 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 783d 1483d 0/28 auto-obsoleted due to no activity on 2023/04/21 23:56

Sample crash report:
INFO: task syz-executor.2:11447 blocked for more than 143 seconds.
      Not tainted 5.15.148-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:24920 pid:11447 ppid:  5875 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 perf_event_free_task+0x555/0x680 kernel/events/core.c:13124
 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: 0033:0x7fb167ecbda9
RSP: 002b:00007fb1663e9078 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fb167ffa1f0 RCX: 00007fb167ecbda9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb167f1847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007fb167ffa1f0 R15: 00007ffcab0e3c68
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91f220 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3266:
 #0: ffff888024635098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc9000229b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:12/4000:
 #0: ffff888011c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90004fafd20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
5 locks held by kworker/u4:1/28836:
5 locks held by kworker/u4:3/11404:
 #0: ffff888011dcd138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
 #1: ffffc90002fa7d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
 #2: ffffffff8d9cead0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:558
 #3: ffffffff8d9da688 (rtnl_mutex){+.+.}-{3:3}, at: ip6gre_exit_batch_net+0xc0/0x460 net/ipv6/ip6_gre.c:1644
 #4: ffffffff8c9237e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #4: ffffffff8c9237e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
3 locks held by syz-executor.0/14401:
1 lock held by syz-executor.0/14409:
2 locks held by syz-executor.0/14538:
1 lock held by syz-executor.0/14641:
2 locks held by syz-executor.0/14723:
2 locks held by syz-executor.0/14811:
2 locks held by syz-executor.0/14986:
2 locks held by syz-executor.0/15226:
2 locks held by syz-executor.0/15305:
2 locks held by syz-executor.0/15311:
2 locks held by syz-executor.0/15422:
2 locks held by syz-executor.0/15537:
2 locks held by syz-executor.1/15665:
 #0: ffffffff8d9cead0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x37b/0x5d0 net/core/net_namespace.c:469
 #1: ffffffff8d9da688 (rtnl_mutex){+.+.}-{3:3}, at: tc_action_net_exit include/net/act_api.h:155 [inline]
 #1: ffffffff8d9da688 (rtnl_mutex){+.+.}-{3:3}, at: gate_exit_net+0x2c/0x100 net/sched/act_gate.c:624
2 locks held by syz-executor.0/15690:
3 locks held by syz-executor.0/15695:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.148-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
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
CPU: 1 PID: 4000 Comm: kworker/1:12 Not tainted 5.15.148-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:nsim_dev_trap_report_work+0xac/0xab0 drivers/net/netdevsim/dev.c:759
Code: 24 08 48 8b 01 48 39 c8 0f 84 9f 09 00 00 48 89 04 24 48 8d a8 50 02 00 00 48 89 e8 48 c1 e8 03 48 89 44 24 28 42 80 3c 38 00 <74> 08 48 89 ef e8 6a 11 c4 fb 48 8b 5d 00 48 89 d8 48 c1 e8 03 42
RSP: 0018:ffffc90004fafb80 EFLAGS: 00000246
RAX: 1ffff1100e2a2b4a RBX: ffff888071515800 RCX: ffff88801bf58000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: ffff888071515a50 R08: dffffc0000000000 R09: ffffed1004076d9a
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880203b6ca8
R13: 0000000000000001 R14: ffff888027cf8470 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c2a6cc8030 CR3: 0000000041853000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/23 07:33 linux-5.15.y 6139f2a02fe0 8d446f15 .config console log report info ci2-linux-5-15-kasan-perf INFO: task hung in perf_event_free_task
* Struck through repros no longer work on HEAD.