INFO: task hung in dev_deactivate_many

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 18522108d53c Merge tag 'batadv-next-for-davem-20180919' of..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=107a6fda400000
kernel config: https://syzkaller.appspot.com/x/.config?x=e79b9299baeb2298
dashboard link: https://syzkaller.appspot.com/bug?extid=677d3da2f84f88d685d1
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
CC: [da...@davemloft.net j...@mojatatu.com ji...@resnulli.us
linux-...@vger.kernel.org net...@vger.kernel.org
xiyou.w...@gmail.com]

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+677d3d...@syzkaller.appspotmail.com

IPv6: ADDRCONF(NETDEV_CHANGE): vcan0: link becomes ready
bond0: mtu greater than device maximum
bond0: mtu greater than device maximum
INFO: task syz-executor3:8698 blocked for more than 140 seconds.
Not tainted 4.19.0-rc4+ #223
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3 D20760 8698 5416 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
schedule+0xfe/0x460 kernel/sched/core.c:3517
exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline]
_synchronize_rcu_expedited+0xc68/0xfd0 kernel/rcu/tree_exp.h:667
synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:795
synchronize_net+0x3b/0x60 net/core/dev.c:9013
dev_deactivate_many+0x543/0xdd0 net/sched/sch_generic.c:1182
__dev_close_many+0x197/0x380 net/core/dev.c:1461
dev_close_many+0x2df/0x860 net/core/dev.c:1499
rollback_registered_many+0x56e/0x1240 net/core/dev.c:7930
unregister_netdevice_many+0xfa/0x4c0 net/core/dev.c:9058
ip_tunnel_delete_nets+0x4d2/0x6d0 net/ipv4/ip_tunnel.c:1073
vti_exit_batch_net+0x22/0x30 net/ipv4/ip_vti.c:448
ops_exit_list.isra.7+0x105/0x160 net/core/net_namespace.c:156
setup_net+0x56e/0x950 net/core/net_namespace.c:331
copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206
ksys_unshare+0x79c/0x10b0 kernel/fork.c:2489
__do_sys_unshare kernel/fork.c:2557 [inline]
__se_sys_unshare kernel/fork.c:2555 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2555
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4572d9
Code: 42 08 48 8b 40 08 48 89 04 24 e8 02 d3 fc ff 48 8b 6c 24 08 48 83 c4
10 c3 e8 e3 2b 00 00 eb c1 cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76
75 48 83 ec 38 48 89 6c 24 30 48 8d 6c 24 30 48 8b
RSP: 002b:00007f201fd4ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f201fd4b6d4 RCX: 00000000004572d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040020000
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7c08 R14: 00000000004caa6a R15: 0000000000000000
INFO: task syz-executor3:8731 blocked for more than 140 seconds.
Not tainted 4.19.0-rc4+ #223
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3 D23608 8731 5416 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
schedule+0xfe/0x460 kernel/sched/core.c:3517
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3575
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
cangw_pernet_exit+0x12/0x30 net/can/gw.c:1005
ops_exit_list.isra.7+0xb0/0x160 net/core/net_namespace.c:153
setup_net+0x56e/0x950 net/core/net_namespace.c:331
copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206
ksys_unshare+0x79c/0x10b0 kernel/fork.c:2489
__do_sys_unshare kernel/fork.c:2557 [inline]
__se_sys_unshare kernel/fork.c:2555 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2555
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4572d9
Code: 42 08 48 8b 40 08 48 89 04 24 e8 02 d3 fc ff 48 8b 6c 24 08 48 83 c4
10 c3 e8 e3 2b 00 00 eb c1 cc 64 48 8b 0c 25 f8 ff ff ff <48> 3b 61 10 76
75 48 83 ec 38 48 89 6c 24 30 48 8d 6c 24 30 48 8b
RSP: 002b:00007f201fd08c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f201fd096d4 RCX: 00000000004572d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040020000
RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d7c08 R14: 00000000004caa6a R15: 0000000000000002
INFO: task syz-executor2:8733 blocked for more than 140 seconds.
Not tainted 4.19.0-rc4+ #223
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2 D23400 8733 5415 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2825 [inline]
__schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
schedule+0xfe/0x460 kernel/sched/core.c:3517
exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline]
_synchronize_rcu_expedited+0xc68/0xfd0 kernel/rcu/tree_exp.h:667
synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:795
synchronize_net+0x3b/0x60 net/core/dev.c:9013
packet_release+0x926/0xda0 net/packet/af_packet.c:3006
__sock_release+0xd7/0x250 net/socket.c:579
sock_close+0x19/0x20 net/socket.c:1141
__fput+0x385/0xa30 fs/file_table.c:278
____fput+0x15/0x20 fs/file_table.c:309
task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:193 [inline]
exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166
prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x410e91
Code: ff 48 8d 05 99 83 0a 01 48 89 84 24 c0 00 00 00 48 8b ac 24 98 00 00
00 48 81 c4 a0 00 00 00 c3 e8 14 90 01 00 0f 0b e8 0d 90 <01> 00 0f 0b e8
06 90 01 00 0f 0b e8 ff 8f 01 00 0f 0b 48 8d 05 63
RSP: 002b:00007ffcb28d5980 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 0000000000410e91
RDX: 0000000000000000 RSI: 0000000000730c90 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000140 R09: ffffffffffffffff
R10: 00000000009301e0 R11: 0000000000000293 R12: 000000000000000d
R13: 0000000000026d5a R14: 0000000000000036 R15: badc0ffeebadface

Showing all locks held in the system:
3 locks held by kworker/1:0/19:
#0: 000000007dabea42 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
__write_once_size include/linux/compiler.h:215 [inline]
#0: 000000007dabea42 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 000000007dabea42 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 000000007dabea42 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 000000007dabea42 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_data kernel/workqueue.c:617 [inline]
#0: 000000007dabea42 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 000000007dabea42 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
process_one_work+0xb43/0x1b90 kernel/workqueue.c:2124
#1: 00000000d7627f72 ((addr_chk_work).work){+.+.}, at:
process_one_work+0xb9a/0x1b90 kernel/workqueue.c:2128
#2: 00000000607a94b9 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by khungtaskd/984:
#0: 00000000ca018959 (rcu_read_lock){....}, at:
debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4435
1 lock held by rsyslogd/5279:
2 locks held by getty/5368:
#0: 0000000065be6c1f (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000856a0626 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5369:
#0: 000000009c7b6e8d (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000009eaeea53 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5370:
#0: 00000000d9b0dfc5 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000eb744490 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5371:
#0: 00000000ef08245a (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 0000000069ad87b0 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5372:
#0: 00000000c0da978e (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000006465851e (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5373:
#0: 00000000ce8e7f27 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000a88160e4 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5374:
#0: 00000000d80673aa (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000002854b404 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by syz-executor3/8698:
#0: 000000008c72c13e (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
#1: 00000000607a94b9 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
2 locks held by syz-executor3/8731:
#0: 000000008c72c13e (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
#1: 00000000607a94b9 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor2/8733:
#0: 000000008f8136b5 (&sb->s_type->i_mutex_key#12){+.+.}, at: inode_lock
include/linux/fs.h:738 [inline]
#0: 000000008f8136b5 (&sb->s_type->i_mutex_key#12){+.+.}, at:
__sock_release+0x8b/0x250 net/socket.c:578

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

NMI backtrace for cpu 0
CPU: 0 PID: 984 Comm: khungtaskd Not tainted 4.19.0-rc4+ #223
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1b3/0x1ed lib/nmi_backtrace.c:62
arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
watchdog+0xb3e/0x1050 kernel/hung_task.c:265
kthread+0x35a/0x420 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10
arch/x86/include/asm/irqflags.h:57


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit: 55e5059cb572 Add linux-next specific files for 20181105
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=11d574f5400000
kernel config: https://syzkaller.appspot.com/x/.config?x=4f1c4c176ce04fdb

dashboard link: https://syzkaller.appspot.com/bug?extid=677d3da2f84f88d685d1
compiler: gcc (GCC) 8.0.1 20180413 (experimental)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14e91fe5400000

CC: [da...@davemloft.net j...@mojatatu.com ji...@resnulli.us
linux-...@vger.kernel.org net...@vger.kernel.org
xiyou.w...@gmail.com]

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+677d3d...@syzkaller.appspotmail.com

IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
IPVS: ftp: loaded support on port[0] = 21
INFO: task kworker/u4:2:32 blocked for more than 140 seconds.
Not tainted 4.20.0-rc1-next-20181105+ #105

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

kworker/u4:2 D18504 32 2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
schedule+0xfe/0x460 kernel/sched/core.c:3516
exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline]
_synchronize_rcu_expedited.constprop.58+0x8df/0x9d0
kernel/rcu/tree_exp.h:620
synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:758
synchronize_net+0x3b/0x60 net/core/dev.c:9062
dev_deactivate_many+0x543/0xdd0 net/sched/sch_generic.c:1222

__dev_close_many+0x197/0x380 net/core/dev.c:1461
dev_close_many+0x2df/0x860 net/core/dev.c:1499

rollback_registered_many+0x543/0x1250 net/core/dev.c:7979
unregister_netdevice_many+0xfa/0x4c0 net/core/dev.c:9107
sit_exit_batch_net+0x5b6/0x800 net/ipv6/sit.c:1885
ops_exit_list.isra.5+0x105/0x160 net/core/net_namespace.c:156
cleanup_net+0x555/0xb10 net/core/net_namespace.c:551
process_one_work+0xc8b/0x1c40 kernel/workqueue.c:2153
worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
kthread+0x35a/0x440 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
INFO: task syz-executor3:7314 blocked for more than 140 seconds.
Not tainted 4.20.0-rc1-next-20181105+ #105

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

syz-executor3 D21656 7314 5725 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
schedule+0xfe/0x460 kernel/sched/core.c:3516
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072

mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77

tc_action_net_exit include/net/act_api.h:133 [inline]
tunnel_key_exit_net+0x7d/0x450 net/sched/act_tunnel_key.c:580
ops_exit_list.isra.5+0x105/0x160 net/core/net_namespace.c:156
setup_net+0x501/0x8d0 net/core/net_namespace.c:331

copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206

ksys_unshare+0x79c/0x10b0 kernel/fork.c:2539
__do_sys_unshare kernel/fork.c:2607 [inline]
__se_sys_unshare kernel/fork.c:2605 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2605
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 44 0f 6f 5e 60 f3 44 0f 6f 66 70 4c 31 df 48 01 de c5 fe 6f 66 e0 4c
29 de 4c 29 db 48 81 fb 00 00 10 00 77 7b 48 81 eb 80 00 <00> 00 c5 fe 6f
46 e0 c5 fe 6f 4e c0 c5 fe 6f 56 a0 c5 fe 6f 5e 80
RSP: 002b:00007feb71ff7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007feb71ff86d4
R13: 00000000004c5199 R14: 00000000004d8998 R15: 00000000ffffffff
INFO: task syz-executor1:7326 blocked for more than 140 seconds.
Not tainted 4.20.0-rc1-next-20181105+ #105

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

syz-executor1 D20896 7326 5726 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
schedule+0xfe/0x460 kernel/sched/core.c:3516
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072

mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77

xfrmi_exit_net+0x208/0x4c0 net/xfrm/xfrm_interface.c:794
ops_exit_list.isra.5+0xb0/0x160 net/core/net_namespace.c:153
setup_net+0x501/0x8d0 net/core/net_namespace.c:331

copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206

ksys_unshare+0x79c/0x10b0 kernel/fork.c:2539
__do_sys_unshare kernel/fork.c:2607 [inline]
__se_sys_unshare kernel/fork.c:2605 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2605
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 44 0f 6f 5e 60 f3 44 0f 6f 66 70 4c 31 df 48 01 de c5 fe 6f 66 e0 4c
29 de 4c 29 db 48 81 fb 00 00 10 00 77 7b 48 81 eb 80 00 <00> 00 c5 fe 6f
46 e0 c5 fe 6f 4e c0 c5 fe 6f 56 a0 c5 fe 6f 5e 80
RSP: 002b:00007fb670b40c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb670b416d4
R13: 00000000004c5199 R14: 00000000004d8998 R15: 00000000ffffffff
INFO: task syz-executor1:7327 blocked for more than 140 seconds.
Not tainted 4.20.0-rc1-next-20181105+ #105

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

syz-executor1 D23432 7327 5726 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
schedule+0xfe/0x460 kernel/sched/core.c:3516
exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline]
_synchronize_rcu_expedited.constprop.58+0x8df/0x9d0
kernel/rcu/tree_exp.h:620
synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:758
synchronize_net+0x3b/0x60 net/core/dev.c:9062
tipc_nametbl_stop+0x968/0xca0 net/tipc/name_table.c:797
tipc_exit_net+0x2d/0x40 net/tipc/core.c:103
ops_exit_list.isra.5+0xb0/0x160 net/core/net_namespace.c:153
setup_net+0x501/0x8d0 net/core/net_namespace.c:331

copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206

ksys_unshare+0x79c/0x10b0 kernel/fork.c:2539
__do_sys_unshare kernel/fork.c:2607 [inline]
__se_sys_unshare kernel/fork.c:2605 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2605
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 44 0f 6f 5e 60 f3 44 0f 6f 66 70 4c 31 df 48 01 de c5 fe 6f 66 e0 4c
29 de 4c 29 db 48 81 fb 00 00 10 00 77 7b 48 81 eb 80 00 <00> 00 c5 fe 6f
46 e0 c5 fe 6f 4e c0 c5 fe 6f 56 a0 c5 fe 6f 5e 80
RSP: 002b:00007fb670b1fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb670b206d4
R13: 00000000004c5199 R14: 00000000004d8998 R15: 00000000ffffffff
INFO: task syz-executor5:7341 blocked for more than 140 seconds.
Not tainted 4.20.0-rc1-next-20181105+ #105

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

syz-executor5 D22744 7341 5734 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
schedule+0xfe/0x460 kernel/sched/core.c:3516
exp_funnel_lock kernel/rcu/tree_exp.h:319 [inline]
_synchronize_rcu_expedited.constprop.58+0x8df/0x9d0
kernel/rcu/tree_exp.h:620
synchronize_rcu_expedited+0x27/0xa0 kernel/rcu/tree_exp.h:758
synchronize_net+0x3b/0x60 net/core/dev.c:9062
tipc_sk_rht_destroy+0x219/0x360 net/tipc/socket.c:2803
tipc_exit_net+0x35/0x40 net/tipc/core.c:104
ops_exit_list.isra.5+0xb0/0x160 net/core/net_namespace.c:153
setup_net+0x501/0x8d0 net/core/net_namespace.c:331

copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206

ksys_unshare+0x79c/0x10b0 kernel/fork.c:2539
__do_sys_unshare kernel/fork.c:2607 [inline]
__se_sys_unshare kernel/fork.c:2605 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2605
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 44 0f 6f 5e 60 f3 44 0f 6f 66 70 4c 31 df 48 01 de c5 fe 6f 66 e0 4c
29 de 4c 29 db 48 81 fb 00 00 10 00 77 7b 48 81 eb 80 00 <00> 00 c5 fe 6f
46 e0 c5 fe 6f 4e c0 c5 fe 6f 56 a0 c5 fe 6f 5e 80
RSP: 002b:00007fae7a6bac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fae7a6bb6d4
R13: 00000000004c5199 R14: 00000000004d8998 R15: 00000000ffffffff
INFO: task syz-executor0:7332 blocked for more than 140 seconds.
Not tainted 4.20.0-rc1-next-20181105+ #105

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

syz-executor0 D22608 7332 5731 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
schedule+0xfe/0x460 kernel/sched/core.c:3516
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072

mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
cangw_pernet_exit+0x12/0x30 net/can/gw.c:1005

ops_exit_list.isra.5+0xb0/0x160 net/core/net_namespace.c:153
setup_net+0x501/0x8d0 net/core/net_namespace.c:331

copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206

ksys_unshare+0x79c/0x10b0 kernel/fork.c:2539
__do_sys_unshare kernel/fork.c:2607 [inline]
__se_sys_unshare kernel/fork.c:2605 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2605
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 44 0f 6f 5e 60 f3 44 0f 6f 66 70 4c 31 df 48 01 de c5 fe 6f 66 e0 4c
29 de 4c 29 db 48 81 fb 00 00 10 00 77 7b 48 81 eb 80 00 <00> 00 c5 fe 6f
46 e0 c5 fe 6f 4e c0 c5 fe 6f 56 a0 c5 fe 6f 5e 80
RSP: 002b:00007fe8550f0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe8550f16d4
R13: 00000000004c5199 R14: 00000000004d8998 R15: 00000000ffffffff
INFO: task syz-executor4:7337 blocked for more than 140 seconds.
Not tainted 4.20.0-rc1-next-20181105+ #105

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

syz-executor4 D23360 7337 5732 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
schedule+0xfe/0x460 kernel/sched/core.c:3516
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072

mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
cangw_pernet_exit+0x12/0x30 net/can/gw.c:1005

ops_exit_list.isra.5+0xb0/0x160 net/core/net_namespace.c:153
setup_net+0x501/0x8d0 net/core/net_namespace.c:331

copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206

ksys_unshare+0x79c/0x10b0 kernel/fork.c:2539
__do_sys_unshare kernel/fork.c:2607 [inline]
__se_sys_unshare kernel/fork.c:2605 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2605
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 44 0f 6f 5e 60 f3 44 0f 6f 66 70 4c 31 df 48 01 de c5 fe 6f 66 e0 4c
29 de 4c 29 db 48 81 fb 00 00 10 00 77 7b 48 81 eb 80 00 <00> 00 c5 fe 6f
46 e0 c5 fe 6f 4e c0 c5 fe 6f 56 a0 c5 fe 6f 5e 80
RSP: 002b:00007fe191da4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe191da56d4
R13: 00000000004c5199 R14: 00000000004d8998 R15: 00000000ffffffff
INFO: task syz-executor2:7343 blocked for more than 140 seconds.
Not tainted 4.20.0-rc1-next-20181105+ #105

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

syz-executor2 D22496 7343 5728 0x80000004
Call Trace:
context_switch kernel/sched/core.c:2831 [inline]
__schedule+0x8cf/0x21d0 kernel/sched/core.c:3472
schedule+0xfe/0x460 kernel/sched/core.c:3516
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3574
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0xaff/0x16f0 kernel/locking/mutex.c:1072

mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77

ip_tunnel_init_net+0x3e2/0xac0 net/ipv4/ip_tunnel.c:1028
vti_init_net+0x84/0x480 net/ipv4/ip_vti.c:437
ops_init+0x101/0x560 net/core/net_namespace.c:129
setup_net+0x362/0x8d0 net/core/net_namespace.c:314

copy_net_ns+0x2b1/0x4a0 net/core/net_namespace.c:437
create_new_namespaces+0x6ad/0x900 kernel/nsproxy.c:107
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:206

ksys_unshare+0x79c/0x10b0 kernel/fork.c:2539
__do_sys_unshare kernel/fork.c:2607 [inline]
__se_sys_unshare kernel/fork.c:2605 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:2605
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: Bad RIP value.
RSP: 002b:00007f6ae1330c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6ae13316d4
R13: 00000000004c5199 R14: 00000000004d8998 R15: 00000000ffffffff

Showing all locks held in the system:

4 locks held by kworker/u4:2/32:
#0: 00000000c29c7628 ((wq_completion)"%s""netns"){+.+.}, at:
__write_once_size include/linux/compiler.h:209 [inline]
#0: 00000000c29c7628 ((wq_completion)"%s""netns"){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 00000000c29c7628 ((wq_completion)"%s""netns"){+.+.}, at: atomic64_set
include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 00000000c29c7628 ((wq_completion)"%s""netns"){+.+.}, at:
atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 00000000c29c7628 ((wq_completion)"%s""netns"){+.+.}, at: set_work_data
kernel/workqueue.c:617 [inline]
#0: 00000000c29c7628 ((wq_completion)"%s""netns"){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 00000000c29c7628 ((wq_completion)"%s""netns"){+.+.}, at:
process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124
#1: 00000000f174895f (net_cleanup_work){+.+.}, at:
process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128
#2: 000000006e017908 (pernet_ops_rwsem){++++}, at: cleanup_net+0x13f/0xb10
net/core/net_namespace.c:518
#3: 00000000871730e0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by khungtaskd/1007:
#0: 0000000005469bfe (rcu_read_lock){....}, at:
debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379
1 lock held by rsyslogd/5589:
#0: 0000000004d1fe5b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200
fs/file.c:766
2 locks held by getty/5679:
#0: 0000000085fea849 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000e0907768 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5680:
#0: 00000000f8a0a173 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000000df10877 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5681:
#0: 000000001d832a30 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000a4966bc3 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5682:
#0: 00000000093f6ad1 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000ab143362 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5683:
#0: 000000007d4733d5 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 0000000069baa170 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5684:
#0: 00000000f22976c1 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 000000005cbcfc1a (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
2 locks held by getty/5685:
#0: 0000000049755cc7 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
#1: 00000000b6011517 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x335/0x1e80 drivers/tty/n_tty.c:2154
3 locks held by kworker/0:1/5935:
#0: 00000000bf03b0aa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
__write_once_size include/linux/compiler.h:209 [inline]
#0: 00000000bf03b0aa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 00000000bf03b0aa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 00000000bf03b0aa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 00000000bf03b0aa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_data kernel/workqueue.c:617 [inline]
#0: 00000000bf03b0aa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 00000000bf03b0aa ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
process_one_work+0xb43/0x1c40 kernel/workqueue.c:2124
#1: 000000000e0cb31e ((addr_chk_work).work){+.+.}, at:
process_one_work+0xb9a/0x1c40 kernel/workqueue.c:2128
#2: 00000000871730e0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
2 locks held by syz-executor3/7314:
#0: 000000006e017908 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
#1: 00000000871730e0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
2 locks held by syz-executor1/7326:
#0: 000000006e017908 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
#1: 00000000871730e0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor1/7327:
#0: 000000006e017908 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
1 lock held by syz-executor5/7341:
#0: 000000006e017908 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
2 locks held by syz-executor0/7332:
#0: 000000006e017908 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
#1: 00000000871730e0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
2 locks held by syz-executor4/7337:
#0: 000000006e017908 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
#1: 00000000871730e0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
2 locks held by syz-executor2/7343:
#0: 000000006e017908 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x28c/0x4a0
net/core/net_namespace.c:433
#1: 00000000871730e0 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77

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

NMI backtrace for cpu 1
CPU: 1 PID: 1007 Comm: khungtaskd Not tainted 4.20.0-rc1-next-20181105+ #105

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]

dump_stack+0x244/0x39d lib/dump_stack.c:113
nmi_cpu_backtrace.cold.2+0x5c/0xa1 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1e8/0x22a lib/nmi_backtrace.c:62

arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline]

check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
watchdog+0xb4c/0x1060 kernel/hung_task.c:289
kthread+0x35a/0x440 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.565
msecs

NMI backtrace for cpu 0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.20.0-rc1-next-20181105+ #105

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011

RIP: 0010:lockdep_hardirqs_off+0xb/0x2b0 kernel/locking/lockdep.c:2819
Code: e9 69 fe ff ff e8 85 05 61 00 e9 42 ff ff ff e8 7b 05 61 00 eb 9d 66
0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 55 <48> 89 e5 41 55
49 89 fd 48 c7 c7 b4 44 15 8a 48 89 fa 41 54 48 c1
RSP: 0018:ffff8801dae072a8 EFLAGS: 00000006
RAX: dffffc0000000000 RBX: 1ffff1003b5c0e5a RCX: ffffffff818595e5
RDX: 0000000000000100 RSI: ffffffff818595ef RDI: ffffffff87d08fe4
RBP: ffff8801dae07358 R08: ffffffff89476ec0 R09: ffffed003b5c59a9
R10: ffffed003b5c59a9 R11: ffff8801dae2cd4b R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff87d08fe4 R15: ffff8801dae079b0
FS: 0000000000000000(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001bbe41000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:108 [inline]
_raw_spin_lock_irqsave+0x74/0xd0 kernel/locking/spinlock.c:152
rq_lock_irqsave kernel/sched/sched.h:1110 [inline]
update_blocked_averages+0x156/0x1e00 kernel/sched/fair.c:7381
_nohz_idle_balance+0x5ba/0x7a0 kernel/sched/fair.c:9456
nohz_idle_balance kernel/sched/fair.c:9509 [inline]
run_rebalance_domains+0x2ec/0x500 kernel/sched/fair.c:9692
__do_softirq+0x308/0xb7e kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x17f/0x1c0 kernel/softirq.c:413
scheduler_ipi+0x55a/0xad0 kernel/sched/core.c:1785
smp_reschedule_interrupt+0x109/0x650 arch/x86/kernel/smp.c:278
reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828
</IRQ>
RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57
Code: 45 d8 e8 7d 49 f2 f9 48 8b 45 d8 e9 ca fe ff ff 48 89 df e8 6c 49 f2
f9 eb 82 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 fb f4 <5d> c3 0f 1f 84
00 00 00 00 00 55 48 89 e5 f4 5d c3 90 90 90 90 90
RSP: 0018:ffffffff89407c10 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: 1ffffffff1280f86 RCX: 0000000000000000
RDX: 1ffffffff12a3f79 RSI: 0000000000000001 RDI: ffffffff8951fbc8
RBP: ffffffff89407c10 R08: ffffffff89476ec0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89407cd0
R13: ffffffff8a1512a0 R14: 0000000000000000 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:151 [inline]
default_idle+0xbf/0x490 arch/x86/kernel/process.c:498
arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:489
default_idle_call+0x6d/0x90 kernel/sched/idle.c:93
cpuidle_idle_call kernel/sched/idle.c:153 [inline]
do_idle+0x49b/0x5c0 kernel/sched/idle.c:262
cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:353
rest_init+0x243/0x372 init/main.c:443
arch_call_rest_init+0xe/0x1b
start_kernel+0x9f0/0xa2b init/main.c:745
x86_64_start_reservations+0x2e/0x30 arch/x86/kernel/head64.c:472
x86_64_start_kernel+0x76/0x79 arch/x86/kernel/head64.c:451
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

[Dmitry Vyukov]

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
master

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[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+677d3d...@syzkaller.appspotmail.com

Tested on:

commit: 8053e5b93eca Merge tag 'trace-v4.20-rc1' of git://git.kern..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=8f559fee2fc3375a

compiler: gcc (GCC) 8.0.1 20180413 (experimental)

Note: testing is done by a robot and is best-effort only.

[Dmitry Vyukov]

Did not happen for 2 months and wasn't reproduced with the repro.

#syz invalid