syzbot


INFO: task hung in _rcu_barrier (2)

Status: auto-closed as invalid on 2019/10/25 08:36
Reported-by: syzbot+00b61d063344fa29ce09@syzkaller.appspotmail.com
First crash: 1831d, last: 1819d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in _rcu_barrier 13 2089d 2108d 0/1 auto-closed as invalid on 2019/03/23 10:41
android-49 INFO: task hung in _rcu_barrier C 1 2047d 1887d 0/3 public: reported C repro on 2019/04/14 08:51
linux-4.19 INFO: task hung in _rcu_barrier 1 906d 906d 0/1 auto-closed as invalid on 2022/04/19 01:50
linux-4.14 INFO: task hung in _rcu_barrier (2) 1 1184d 1184d 0/1 auto-closed as invalid on 2021/07/15 03:03
linux-4.14 INFO: task hung in _rcu_barrier 3 1494d 1526d 0/1 auto-closed as invalid on 2020/09/08 15:22
upstream INFO: task hung in _rcu_barrier net 3 2068d 2110d 0/28 auto-closed as invalid on 2019/04/13 07:47

Sample crash report:
ip6_tunnel: ip6tnl1 xmit: Local address not yet configured!
INFO: task kworker/u4:32:25200 blocked for more than 140 seconds.
      Not tainted 4.14.128+ #10
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:32   D26776 25200      2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 schedule_timeout+0x736/0xe80 kernel/time/timer.c:1721
 do_wait_for_common kernel/sched/completion.c:91 [inline]
 __wait_for_common kernel/sched/completion.c:112 [inline]
 wait_for_common+0x29c/0x470 kernel/sched/completion.c:123
 _rcu_barrier+0x27b/0x3e0 kernel/rcu/tree.c:3611
 cleanup_net+0x4a3/0x860 net/core/net_namespace.c:495
 process_one_work+0x7c6/0x1510 kernel/workqueue.c:2134
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2271
 kthread+0x310/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.?}, at: [<00000000ccf7df6d>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
2 locks held by getty/1758:
 #0:  (&tty->ldisc_sem){++++}, at: [<0000000029ba54bb>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<00000000499c7b9c>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.0/19844:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.}, at: [<00000000a19fa244>] inode_lock include/linux/fs.h:718 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.}, at: [<00000000a19fa244>] __sock_release+0x86/0x2c0 net/socket.c:601
3 locks held by kworker/u4:32/25200:
 #0:  ("%s""netns"){+.+.}, at: [<000000009436b6c3>] process_one_work+0x6e5/0x1510 kernel/workqueue.c:2105
 #1:  (net_cleanup_work){+.+.}, at: [<00000000e04a9e79>] process_one_work+0x71b/0x1510 kernel/workqueue.c:2109
 #2:  (rcu_preempt_state.barrier_mutex){+.+.}, at: [<00000000d00aa196>] _rcu_barrier+0x56/0x3e0 kernel/rcu/tree.c:3546

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

NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.128+ #10
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 13458 Comm: syz-executor.0 Not tainted 4.14.128+ #10
task: 0000000044a4d1e6 task.stack: 00000000860ca578
RIP: 0033:0x4018e4
RSP: 002b:00007f641c958b50 EFLAGS: 00000206
RAX: 0000000022d23447 RBX: 0000000000000fff RCX: 00000000004592c9
RDX: 0000000000412ef1 RSI: 0000000000a74ef0 RDI: 0000000000000043
RBP: 00000000004bdcb4 R08: 000000000000000e R09: 0000000000000000
R10: 00007f641c959700 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000004c67a4 R14: 00000000004db660 R15: 00000000ffffffff
FS:  00007f641c959700(0000) GS:ffff8881db800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f641c955fec CR3: 00000001ce45c002 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/06/21 16:18 android-4.14 334aa9b115f3 34bf9440 .config console log report ci-android-414-kasan-gce-root
2019/06/09 11:34 android-4.14 225970c2e89e 0159583c .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.