syzbot


INFO: task hung in linkwatch_event

Status: auto-closed as invalid on 2019/10/25 08:50
Reported-by: syzbot+550ce8a24f7d69f3a2ba@syzkaller.appspotmail.com
First crash: 2213d, last: 1814d
Similar bugs (12)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in linkwatch_event C 7 1614d 1834d 0/1 public: reported C repro on 2019/04/10 16:14
linux-4.14 INFO: task hung in linkwatch_event (2) 1 635d 635d 0/1 auto-obsoleted due to no activity on 2022/11/19 11:58
android-44 INFO: task hung in linkwatch_event 6 2050d 2196d 0/2 auto-closed as invalid on 2019/03/05 13:11
linux-5.15 INFO: task hung in linkwatch_event 26 30d 97d 0/3 upstream: reported on 2024/01/11 11:32
upstream INFO: task hung in linkwatch_event net C 82 1643d 2254d 0/26 closed as dup on 2018/02/14 15:33
linux-4.14 INFO: task hung in linkwatch_event 5 1319d 1446d 0/1 auto-closed as invalid on 2021/01/05 01:42
linux-4.19 INFO: task hung in linkwatch_event (2) C error 217 410d 1498d 0/1 upstream: reported C repro on 2020/03/11 20:12
upstream INFO: task hung in linkwatch_event (2) net C done done 1033 724d 1449d 20/26 fixed on 2022/05/13 11:13
linux-4.19 INFO: task hung in linkwatch_event 3 1652d 1765d 0/1 auto-closed as invalid on 2020/02/07 01:11
upstream INFO: task hung in linkwatch_event (3) net 302 10d 512d 0/26 upstream: reported on 2022/11/22 17:04
linux-4.14 INFO: task hung in linkwatch_event (3) 2 470d 470d 0/1 upstream: reported on 2023/01/03 10:49
linux-6.1 INFO: task hung in linkwatch_event 2 256d 371d 0/3 auto-obsoleted due to no activity on 2023/11/14 00:59

Sample crash report:
INFO: task kworker/1:1:22 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:1     D26856    22      2 0x80000000
Workqueue: events linkwatch_event
 ffff8801d9c20000 0000000000000000 ffff88002445e880 ffff8801a59a4740
 ffff8801db721018 ffff8801d9c2fae8 ffffffff828075c2 0000000000000002
 ffff8801d9c208b0 ffffed003b384115 00ff8801d9c20000 ffff8801db7218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828094a3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff8280b51d>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8280b51d>] mutex_lock_nested+0x38d/0x900 kernel/locking/mutex.c:621
 [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff823583de>] linkwatch_event+0xe/0x60 net/core/link_watch.c:236
 [<ffffffff81131001>] process_one_work+0x831/0x15f0 kernel/workqueue.c:2092
 [<ffffffff81131e96>] worker_thread+0xd6/0x1140 kernel/workqueue.c:2226
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
3 locks held by kworker/1:1/22:
 #0:  ("events"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((linkwatch_work).work){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fe63f>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
3 locks held by ipv6_addrconf/350:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((addr_chk_work).work){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
 #2:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
1 lock held by rsyslogd/1896:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156cc7c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2028:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815952>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81d37362>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
2 locks held by kworker/u4:120/9904:
 #0:  ("events_unbound"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((reaper_work).work){+.+...}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
2 locks held by syz-executor.2/27940:
 #0:  (rtnl_mutex){+.+.+.}, at: [<ffffffff823412d7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 #1:  (rcu_preempt_state.exp_mutex){+.+...}, at: [<ffffffff8124a749>] exp_funnel_lock kernel/rcu/tree_exp.h:256 [inline]
 #1:  (rcu_preempt_state.exp_mutex){+.+...}, at: [<ffffffff8124a749>] _synchronize_rcu_expedited+0x339/0x840 kernel/rcu/tree_exp.h:569

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #1
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000001 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b4df89>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b4df1c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810984b4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8131c65d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131c65d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131c65d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131c65d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff82816496

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/05/01 00:16 https://android.googlesource.com/kernel/common android-4.9 8fe428403e30 618456b4 .config console log report ci-android-49-kasan-gce
2019/03/04 04:21 https://android.googlesource.com/kernel/common android-4.9 1597fdfe52ba 1c0e457a .config console log report ci-android-49-kasan-gce-root
2019/02/06 13:36 https://android.googlesource.com/kernel/common android-4.9 7d08263a1394 d25487bc .config console log report ci-android-49-kasan-gce-root
2018/12/25 00:08 https://android.googlesource.com/kernel/common android-4.9 a2f9236e8131 8a41a0ad .config console log report ci-android-49-kasan-gce-root
2018/09/27 20:47 https://android.googlesource.com/kernel/common android-4.9 aa4de6f13f5d 0c2fa87b .config console log report ci-android-49-kasan-gce
2018/09/20 16:51 https://android.googlesource.com/kernel/common android-4.9 ba01a4255d95 565a5452 .config console log report ci-android-49-kasan-gce-root
2018/09/06 21:28 https://android.googlesource.com/kernel/common android-4.9 dcae9fa1319b 0bb7a7eb .config console log report ci-android-49-kasan-gce-root
2018/06/10 23:19 https://android.googlesource.com/kernel/common android-4.9 db2c520bb56b 866118af .config console log report ci-android-49-kasan-gce-root
2018/05/12 10:38 https://android.googlesource.com/kernel/common android-4.9 c2f9bce9fee8 e726f42b .config console log report ci-android-49-kasan-gce-root
2018/05/02 01:47 https://android.googlesource.com/kernel/common android-4.9 19bd3e34d859 d5b114b4 .config console log report ci-android-49-kasan-gce
2018/03/27 18:25 https://android.googlesource.com/kernel/common android-4.9 dd1e37e64645 bf5e585c .config console log report ci-android-49-kasan-gce
2018/11/13 04:10 https://android.googlesource.com/kernel/common android-4.9 109a48ed2f69 74dbb806 .config console log report ci-android-49-kasan-gce-386
2018/05/04 11:23 https://android.googlesource.com/kernel/common android-4.9 0e25e2cab07a 9ce14f4b .config console log report ci-android-49-kasan-gce-386
* Struck through repros no longer work on HEAD.