syzbot


INFO: task hung in namespace_unlock

Status: auto-closed as invalid on 2019/06/26 03:51
Reported-by: syzbot+4dc16c98cfe818a2448e@syzkaller.appspotmail.com
First crash: 2005d, last: 2005d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in namespace_unlock (2) kernel 9 1802d 1975d 0/27 auto-closed as invalid on 2019/10/25 14:11
upstream INFO: task hung in namespace_unlock fs 15 2180d 2189d 8/27 fixed on 2018/07/09 18:05
android-49 INFO: task hung in namespace_unlock 3 1771d 1898d 0/3 auto-closed as invalid on 2019/12/17 06:15

Sample crash report:
audit: type=1400 audit(2000000170.080:63768): avc:  denied  { search } for  pid=190 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:netcontrol_device_t:s0 tclass=dir permissive=1
audit: type=1400 audit(2000000170.110:63769): avc:  denied  { search } for  pid=28948 comm="udevd" name="/" dev="sysfs" ino=1 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:netcontrol_device_t:s0 tclass=dir permissive=1
INFO: task syz-executor2:1852 blocked for more than 140 seconds.
      Not tainted 4.14.90+ #29
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2   D27112  1852      1 0x00000004
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 schedule_timeout+0x710/0xe60 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+0x3bc/0x4e0 kernel/sched/completion.c:123
 __wait_rcu_gp+0x250/0x3a0 kernel/rcu/update.c:413
 synchronize_rcu.part.43+0xd2/0xe0 kernel/rcu/tree_plugin.h:764
 namespace_unlock+0xef/0x110 fs/namespace.c:1466
 do_umount fs/namespace.c:1668 [inline]
 SYSC_umount fs/namespace.c:1763 [inline]
 SyS_umount+0x610/0xc90 fs/namespace.c:1732
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45a407
RSP: 002b:00007ffd8cfc5b88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045a407
RDX: 0000000000402f40 RSI: 0000000000000002 RDI: 00007ffd8cfc5c30
RBP: 0000000000000f0d R08: 0000000000000000 R09: 000000000000000b
R10: 0000000000000005 R11: 0000000000000206 R12: 00007ffd8cfc6cc0
R13: 0000000000b3c940 R14: 0000000000000000 R15: 0000000000000002
INFO: task syz-executor1:19487 blocked for more than 140 seconds.
      Not tainted 4.14.90+ #29
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D26680 19487   1869 0x80000002
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893
 _rcu_barrier+0x5b/0x3f0 kernel/rcu/tree.c:3538
 netdev_run_todo+0x112/0x750 net/core/dev.c:7893
 tun_detach drivers/net/tun.c:587 [inline]
 tun_chr_close+0x45/0x50 drivers/net/tun.c:2661
 __fput+0x25e/0x6f0 fs/file_table.c:210
 task_work_run+0x116/0x190 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x8fb/0x28c0 kernel/exit.c:865
 do_group_exit+0x100/0x2e0 kernel/exit.c:968
 get_signal+0x4e5/0x1470 kernel/signal.c:2348
 do_signal+0x8f/0x1660 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x116/0x150 arch/x86/entry/common.c:159
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:267 [inline]
 do_syscall_64+0x35d/0x4b0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4579b9
RSP: 002b:00007f2c01918c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000129
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00000000004579b9
RDX: 0000000000000016 RSI: 0000000000000947 RDI: 0000000000000947
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000100 R11: 0000000000000246 R12: 00007f2c019196d4
R13: 00000000004c456d R14: 00000000004d7a40 R15: 00000000ffffffff
INFO: task kworker/u4:13:32739 blocked for more than 140 seconds.
      Not tainted 4.14.90+ #29
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:13   D26552 32739      2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
 schedule+0x7f/0x1b0 kernel/sched/core.c:3490
 schedule_timeout+0x710/0xe60 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+0x3bc/0x4e0 kernel/sched/completion.c:123
 _rcu_barrier+0x27b/0x3f0 kernel/rcu/tree.c:3603
 netdev_run_todo+0x112/0x750 net/core/dev.c:7893
 sit_exit_net+0x42f/0x600 net/ipv6/sit.c:1869
 ops_exit_list.isra.3+0xa8/0x150 net/core/net_namespace.c:142
 cleanup_net+0x3e9/0x880 net/core/net_namespace.c:483
 process_one_work+0x86e/0x1670 kernel/workqueue.c:2114
 worker_thread+0xdc/0x1000 kernel/workqueue.c:2248
 kthread+0x348/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff9f804837>] debug_show_all_locks+0x74/0x20f kernel/locking/lockdep.c:4541
2 locks held by getty/1758:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffffa0340c20>] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffffa033c07f>] n_tty_read+0x1ff/0x1700 drivers/tty/n_tty.c:2156
3 locks held by kworker/0:2/2837:
 #0:  ("events"){+.+.}, at: [<ffffffff9f729534>] process_one_work+0x784/0x1670 kernel/workqueue.c:2085
 #1:  ((&map->work)){+.+.}, at: [<ffffffff9f72956c>] process_one_work+0x7bc/0x1670 kernel/workqueue.c:2089
 #2:  (rcu_preempt_state.barrier_mutex){+.+.}, at: [<ffffffff9f84ae9b>] _rcu_barrier+0x5b/0x3f0 kernel/rcu/tree.c:3538
1 lock held by syz-executor1/19075:
 #0:  (&sb->s_type->i_mutex_key#8){+.+.}, at: [<ffffffffa08a79e4>] inode_lock include/linux/fs.h:715 [inline]
 #0:  (&sb->s_type->i_mutex_key#8){+.+.}, at: [<ffffffffa08a79e4>] __sock_release+0x84/0x250 net/socket.c:601
1 lock held by syz-executor1/19487:
 #0:  (rcu_preempt_state.barrier_mutex){+.+.}, at: [<ffffffff9f84ae9b>] _rcu_barrier+0x5b/0x3f0 kernel/rcu/tree.c:3538
4 locks held by kworker/u4:13/32739:
 #0:  ("%s""netns"){+.+.}, at: [<ffffffff9f729534>] process_one_work+0x784/0x1670 kernel/workqueue.c:2085
 #1:  (net_cleanup_work){+.+.}, at: [<ffffffff9f72956c>] process_one_work+0x7bc/0x1670 kernel/workqueue.c:2089
 #2:  (net_mutex){+.+.}, at: [<ffffffffa08f918c>] cleanup_net+0x14c/0x880 net/core/net_namespace.c:449
 #3:  (rcu_preempt_state.barrier_mutex){+.+.}, at: [<ffffffff9f84ae9b>] _rcu_barrier+0x5b/0x3f0 kernel/rcu/tree.c:3538
2 locks held by kworker/0:4/2348:
 #0:  ("events"){+.+.}, at: [<ffffffff9f729534>] process_one_work+0x784/0x1670 kernel/workqueue.c:2085
 #1:  ((&ns->proc_work)){+.+.}, at: [<ffffffff9f72956c>] process_one_work+0x7bc/0x1670 kernel/workqueue.c:2089
2 locks held by kworker/0:5/2520:
 #0:  ("events"){+.+.}, at: [<ffffffff9f729534>] process_one_work+0x784/0x1670 kernel/workqueue.c:2085
 #1:  (key_gc_work){+.+.}, at: [<ffffffff9f72956c>] process_one_work+0x7bc/0x1670 kernel/workqueue.c:2089
3 locks held by kworker/0:6/2521:
 #0:  ("events"){+.+.}, at: [<ffffffff9f729534>] process_one_work+0x784/0x1670 kernel/workqueue.c:2085
 #1:  ((&map->work)){+.+.}, at: [<ffffffff9f72956c>] process_one_work+0x7bc/0x1670 kernel/workqueue.c:2089
 #2:  (rcu_preempt_state.barrier_mutex){+.+.}, at: [<ffffffff9f84ae9b>] _rcu_barrier+0x5b/0x3f0 kernel/rcu/tree.c:3538

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

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.90+ #29
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x11b lib/dump_stack.c:53
 nmi_cpu_backtrace.cold.0+0x47/0x85 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x121/0x146 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline]
 watchdog+0x574/0xa70 kernel/hung_task.c:252
 kthread+0x348/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2413 Comm: syz-executor5 Not tainted 4.14.90+ #29
task: ffff8881987b0000 task.stack: ffff8881c8c20000
RIP: 0010:___bpf_prog_run+0xcf/0x5c70 kernel/bpf/core.c:885
RSP: 0018:ffff8881c8c27a40 EFLAGS: 00000246
RAX: ffffffff9f9a46c7 RBX: dffffc0000000000 RCX: 0000000000040000
RDX: 1ffffffff4292cd1 RSI: ffffc9000c782000 RDI: ffffffffa1496688
RBP: ffff8881c8c27b70 R08: 0000000000000000 R09: 0000000000000000
R10: 1ffff11039184f6f R11: 0000000000000001 R12: ffffffffa1496560
R13: 1ffff11039184f4f R14: ffffed1039184f74 R15: ffffc900002ea038
FS:  00007f26fbae4700(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000240c000 CR3: 00000001d6728004 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
Code: 7f 08 84 c0 0f 85 a0 3e 00 00 41 0f b6 07 48 8d 3c c5 60 65 49 a1 48 89 fa 48 c1 ea 03 80 3c 1a 00 0f 85 71 3e 00 00 49 8b 04 c4 <e9> ec 09 86 01 e8 e7 c2 f6 ff 48 c7 c6 e0 64 49 a1 48 c7 c7 20 

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/12/28 03:50 android-4.14 815e34f802d8 af317504 .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.