syzbot


INFO: task hung in fib6_rules_net_exit (2)

Status: auto-closed as invalid on 2020/01/31 05:34
Reported-by: syzbot+1b97cb40abc8e0cc8618@syzkaller.appspotmail.com
First crash: 1659d, last: 1659d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in fib6_rules_net_exit 1 819d 819d 0/1 auto-closed as invalid on 2022/05/19 15:58
linux-4.19 INFO: task hung in fib6_rules_net_exit (2) 1 626d 626d 0/1 auto-obsoleted due to no activity on 2022/11/29 01:33
upstream INFO: task hung in fib6_rules_net_exit (2) net 7 1209d 1300d 0/26 auto-closed as invalid on 2021/03/25 09:49
upstream INFO: task hung in fib6_rules_net_exit net 1 2211d 2209d 0/26 closed as dup on 2018/03/31 16:17
android-49 INFO: task hung in fib6_rules_net_exit 1 1997d 1830d 0/3 auto-closed as invalid on 2019/04/28 09:31
upstream INFO: task hung in fib6_rules_net_exit (3) net 24 910d 944d 0/26 auto-closed as invalid on 2022/01/18 22:47

Sample crash report:
ip6_tunnel:  xmit: Local address not yet configured!
ip6_tunnel:  xmit: Local address not yet configured!
ip6_tunnel: a xmit: Local address not yet configured!
INFO: task kworker/u4:7:2373 blocked for more than 140 seconds.
      Not tainted 4.9.194+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:7    D26016  2373      2 0x80000000
Workqueue: netns cleanup_net
 0000000000000087 ffff8801a4240000 ffff8801ca0e4780 ffff8801db721000
 ffff8801d1145f00 ffff8801db721018 ffff8801a424f938 ffffffff8281af8e
 ffff8801a424f958 ffffffff81bd0269 00ffffff8167e35e ffff8801db7218f0
Call Trace:
 [<000000003167e0f6>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
 [<00000000ecd3961a>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
 [<00000000d1720e9b>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<00000000d1720e9b>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
 [<000000006188c393>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<000000008aa38efb>] fib6_rules_net_exit+0x12/0x50 net/ipv6/fib6_rules.c:318
 [<00000000c10c8361>] ops_exit_list.isra.0+0xb0/0x160 net/core/net_namespace.c:136
 [<00000000664a9357>] cleanup_net+0x3d6/0x8a0 net/core/net_namespace.c:474
 [<00000000eab322a5>] process_one_work+0x88b/0x1600 kernel/workqueue.c:2114
 [<0000000040bca397>] worker_thread+0x5df/0x11d0 kernel/workqueue.c:2251
 [<00000000b78e6a96>] kthread+0x278/0x310 kernel/kthread.c:211
 [<000000003223c68a>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<00000000b91a64c5>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
 #0:  (rcu_read_lock){......}, at: [<00000000b91a64c5>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
 #1:  (tasklist_lock){.+.+..}, at: [<00000000d74ac53a>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336
3 locks held by rs:main Q:Reg/1894:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<000000004faf6cbf>] __fdget_pos+0xa8/0xd0 fs/file.c:782
 #1:  (sb_writers#4){.+.+.+}, at: [<00000000190f6d1b>] file_start_write include/linux/fs.h:2646 [inline]
 #1:  (sb_writers#4){.+.+.+}, at: [<00000000190f6d1b>] vfs_write+0x3e9/0x520 fs/read_write.c:558
 #2:  (&sb->s_type->i_mutex_key#9){++++++}, at: [<000000001fee7b25>] inode_lock include/linux/fs.h:771 [inline]
 #2:  (&sb->s_type->i_mutex_key#9){++++++}, at: [<000000001fee7b25>] __generic_file_fsync+0xcd/0x1c0 fs/libfs.c:978
1 lock held by rsyslogd/1897:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<000000004faf6cbf>] __fdget_pos+0xa8/0xd0 fs/file.c:782
2 locks held by getty/2024:
 #0:  (&tty->ldisc_sem){++++++}, at: [<000000001e4bd477>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<00000000954356a4>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
4 locks held by kworker/u4:7/2373:
 #0:  ("%s""netns"){.+.+.+}, at: [<00000000871c0cd6>] process_one_work+0x790/0x1600 kernel/workqueue.c:2107
 #1:  (net_cleanup_work){+.+.+.}, at: [<0000000035b425d4>] process_one_work+0x7ce/0x1600 kernel/workqueue.c:2111
 #2:  (net_mutex){+.+.+.}, at: [<00000000e6e47d15>] cleanup_net+0x131/0x8a0 net/core/net_namespace.c:440
 #3:  (rtnl_mutex){+.+.+.}, at: [<000000006188c393>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by kworker/0:4/5555:
 #0:  ("events"){.+.+.+}, at: [<00000000871c0cd6>] process_one_work+0x790/0x1600 kernel/workqueue.c:2107
 #1:  ((&rew.rew_work)){+.+...}, at: [<0000000035b425d4>] process_one_work+0x7ce/0x1600 kernel/workqueue.c:2111
3 locks held by kworker/1:0/26780:
 #0:  ("%s"("ipv6_addrconf")){.+.+..}, at: [<00000000871c0cd6>] process_one_work+0x790/0x1600 kernel/workqueue.c:2107
 #1:  ((addr_chk_work).work){+.+...}, at: [<0000000035b425d4>] process_one_work+0x7ce/0x1600 kernel/workqueue.c:2111
 #2:  (rtnl_mutex){+.+.+.}, at: [<000000006188c393>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
2 locks held by syz-executor.0/1966:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000004417a77a>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000004417a77a>] rtnetlink_rcv+0x1c/0x40 net/core/rtnetlink.c:4086
 #1:  (rcu_preempt_state.exp_mutex){+.+...}, at: [<000000001281f5f9>] exp_funnel_lock kernel/rcu/tree_exp.h:256 [inline]
 #1:  (rcu_preempt_state.exp_mutex){+.+...}, at: [<000000001281f5f9>] _synchronize_rcu_expedited+0x339/0x850 kernel/rcu/tree_exp.h:569
1 lock held by syz-executor.2/1992:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000004417a77a>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000004417a77a>] rtnetlink_rcv+0x1c/0x40 net/core/rtnetlink.c:4086
1 lock held by syz-executor.2/1998:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000004417a77a>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000004417a77a>] rtnetlink_rcv+0x1c/0x40 net/core/rtnetlink.c:4086
1 lock held by syz-executor.5/1990:
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000004417a77a>] rtnl_lock net/core/rtnetlink.c:70 [inline]
 #0:  (rtnl_mutex){+.+.+.}, at: [<000000004417a77a>] rtnetlink_rcv+0x1c/0x40 net/core/rtnetlink.c:4086

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.194+ #0
 ffff8801d98d7cc8 ffffffff81b67001 0000000000000000 0000000000000000
 0000000000000000 ffffffff81099d01 dffffc0000000000 ffff8801d98d7d00
 ffffffff81b7229c 0000000000000000 0000000000000000 0000000000000000
Call Trace:
 [<00000000aacd9939>] __dump_stack lib/dump_stack.c:15 [inline]
 [<00000000aacd9939>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<000000009e58c4ea>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
 [<0000000006179039>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
 [<000000006ffce282>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<000000000f9ee59d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<000000000f9ee59d>] check_hung_task kernel/hung_task.c:126 [inline]
 [<000000000f9ee59d>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
 [<000000000f9ee59d>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
 [<00000000b78e6a96>] kthread+0x278/0x310 kernel/kthread.c:211
 [<000000003223c68a>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff8282a0e1

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/03 05:33 https://android.googlesource.com/kernel/common android-4.9 7fe05eede1c8 2e29b534 .config console log report ci-android-49-kasan-gce-root
* Struck through repros no longer work on HEAD.