INFO: task hung in addrconf_dad_work

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: def4c11b Linux 4.19.68
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=147b506c600000
kernel config: https://syzkaller.appspot.com/x/.config?x=3dc6d2a830ef7eb2
dashboard link: https://syzkaller.appspot.com/bug?extid=67657682b3fbe25029f9
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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+676576...@syzkaller.appspotmail.com

protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
INFO: task kworker/0:3:7639 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/0:3 D26144 7639 2 0x80000000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
addrconf_dad_work+0xad/0x1150 net/ipv6/addrconf.c:3974
process_one_work+0x989/0x1750 kernel/workqueue.c:2153
worker_thread+0x98/0xe40 kernel/workqueue.c:2296
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task kworker/1:5:8209 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:5 D27808 8209 2 0x80000000
net_ratelimit: 26 callbacks suppressed
protocol 88fb is buggy, dev hsr_slave_0
Workqueue: ipv6_addrconf addrconf_dad_work
protocol 88fb is buggy, dev hsr_slave_1
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
addrconf_dad_work+0xad/0x1150 net/ipv6/addrconf.c:3974
process_one_work+0x989/0x1750 kernel/workqueue.c:2153
worker_thread+0x98/0xe40 kernel/workqueue.c:2296
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task kworker/1:0:29463 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/1:0 D27768 29463 2 0x80000000
Workqueue: events switchdev_deferred_process_work
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:150
process_one_work+0x989/0x1750 kernel/workqueue.c:2153
worker_thread+0x98/0xe40 kernel/workqueue.c:2296
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task syz-executor.5:1368 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D28152 1368 7646 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline]
_synchronize_rcu_expedited+0x6b6/0x7f0 kernel/rcu/tree_exp.h:667
synchronize_rcu_expedited kernel/rcu/tree_exp.h:795 [inline]
synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:784
synchronize_net+0x3b/0x60 net/core/dev.c:9068
dev_deactivate_many+0x46f/0xb60 net/sched/sch_generic.c:1181
__dev_close_many+0x13d/0x300 net/core/dev.c:1475
__dev_close net/core/dev.c:1500 [inline]
__dev_change_flags+0x29a/0x6c0 net/core/dev.c:7496
dev_change_flags+0x8a/0x150 net/core/dev.c:7567
devinet_ioctl+0x1354/0x1c10 net/ipv4/devinet.c:1100
inet_ioctl+0x1f4/0x370 net/ipv4/af_inet.c:954
packet_ioctl+0xc5/0x2b0 net/packet/af_packet.c:4109
sock_do_ioctl+0xd8/0x2f0 net/socket.c:950
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: 48 39 f7 72 ed 66 0f 3a 61 4e ff 0c 4c 39 c9 77 9a 48 8d 7e ff 48 01
cf 4c 29 d7 49 89 3b c3 cc cc 48 8b 74 24 08 48 8b 5c 24 <10> 8a 44 24 20
4c 8d 44 24 28 e9 28 00 00 00 cc cc cc cc cc cc cc
RSP: 002b:00007fd415efac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879
RDX: 0000000020000100 RSI: 0000000000008914 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
protocol 88fb is buggy, dev hsr_slave_0
protocol 88fb is buggy, dev hsr_slave_1
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd415efb6d4
R13: 00000000004c5695 R14: 00000000004d9da8 R15: 00000000ffffffff
INFO: task syz-executor.5:1375 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D26600 1375 7646 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
addrconf_add_ifaddr+0x132/0x1c0 net/ipv6/addrconf.c:2991
inet6_ioctl+0x126/0x1c0 net/ipv6/af_inet6.c:562
sock_do_ioctl+0xd8/0x2f0 net/socket.c:950
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: Bad RIP value.
RSP: 002b:00007fd415eb8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879
RDX: 0000000020000000 RSI: 0000000000008916 RDI: 0000000000000004
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd415eb96d4
R13: 00000000004c5513 R14: 00000000004d9b98 R15: 00000000ffffffff
INFO: task syz-executor.5:1404 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5 D28384 1404 7646 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
devinet_ioctl+0x1c0/0x1c10 net/ipv4/devinet.c:1027
inet_ioctl+0x1f4/0x370 net/ipv4/af_inet.c:954
packet_ioctl+0xc5/0x2b0 net/packet/af_packet.c:4109
sock_do_ioctl+0xd8/0x2f0 net/socket.c:950
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: Bad RIP value.
RSP: 002b:00007fd415e97c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879
RDX: 0000000020000080 RSI: 0000000000008914 RDI: 0000000000000003
RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd415e986d4
R13: 00000000004c5695 R14: 00000000004d9da8 R15: 00000000ffffffff
INFO: task syz-executor.4:1381 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D26472 1381 7643 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
devinet_ioctl+0x1c0/0x1c10 net/ipv4/devinet.c:1027
inet_ioctl+0x1f4/0x370 net/ipv4/af_inet.c:954
packet_ioctl+0xc5/0x2b0 net/packet/af_packet.c:4109
sock_do_ioctl+0xd8/0x2f0 net/socket.c:950
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: Bad RIP value.
RSP: 002b:00007fc145b8ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879
RDX: 0000000020000100 RSI: 0000000000008914 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc145b8b6d4
R13: 00000000004c5695 R14: 00000000004d9da8 R15: 00000000ffffffff
INFO: task syz-executor.3:1382 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D28216 1382 7637 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline]
_synchronize_rcu_expedited+0x6b6/0x7f0 kernel/rcu/tree_exp.h:667
synchronize_rcu_expedited kernel/rcu/tree_exp.h:795 [inline]
synchronize_rcu_expedited+0x35/0xb0 kernel/rcu/tree_exp.h:784
synchronize_rcu.part.0+0x76/0xe0 kernel/rcu/tree_plugin.h:818
synchronize_rcu+0x27/0xa0 kernel/rcu/tree_plugin.h:821
pfkey_release+0x270/0x330 net/key/af_key.c:193
__sock_release+0xce/0x2a0 net/socket.c:579
sock_close+0x1b/0x30 net/socket.c:1140
__fput+0x2dd/0x8b0 fs/file_table.c:278
____fput+0x16/0x20 fs/file_table.c:309
task_work_run+0x145/0x1c0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:193 [inline]
exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413561
Code: Bad RIP value.
RSP: 002b:00007ffd4af3f890 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000413561
RDX: 0000000000000000 RSI: 0000000000000081 RDI: 0000000000000006
RBP: 0000000000000000 R08: 00000000007610b8 R09: ffffffffffffffff
R10: 00007ffd4af3f960 R11: 0000000000000293 R12: 000000000075bf20
R13: 0000000000000003 R14: 00000000007610c0 R15: ffffffffffffffff
INFO: task syz-executor.3:1385 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D28600 1385 7637 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
devinet_ioctl+0x1c0/0x1c10 net/ipv4/devinet.c:1027
inet_ioctl+0x1f4/0x370 net/ipv4/af_inet.c:954
packet_ioctl+0xc5/0x2b0 net/packet/af_packet.c:4109
sock_do_ioctl+0xd8/0x2f0 net/socket.c:950
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: Bad RIP value.
RSP: 002b:00007f883f4fec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879
RDX: 0000000020000100 RSI: 0000000000008914 RDI: 0000000000000003
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f883f4ff6d4
R13: 00000000004c5695 R14: 00000000004d9da8 R15: 00000000ffffffff
INFO: task syz-executor.3:1390 blocked for more than 140 seconds.
Not tainted 4.19.68 #42
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3 D26896 1390 7637 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3576
__mutex_lock_common kernel/locking/mutex.c:1002 [inline]
__mutex_lock+0x726/0x1300 kernel/locking/mutex.c:1072
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
rtnl_lock+0x17/0x20 net/core/rtnetlink.c:77
addrconf_add_ifaddr+0x132/0x1c0 net/ipv6/addrconf.c:2991
inet6_ioctl+0x126/0x1c0 net/ipv6/af_inet6.c:562
sock_do_ioctl+0xd8/0x2f0 net/socket.c:950
sock_ioctl+0x325/0x610 net/socket.c:1074
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:501 [inline]
do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:688
ksys_ioctl+0xab/0xd0 fs/ioctl.c:705
__do_sys_ioctl fs/ioctl.c:712 [inline]
__se_sys_ioctl fs/ioctl.c:710 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:710
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: Bad RIP value.
RSP: 002b:00007f883f4ddc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459879
RDX: 0000000020000000 RSI: 0000000000008916 RDI: 0000000000000004
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f883f4de6d4
R13: 00000000004c5513 R14: 00000000004d9b98 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/1036:
#0: 00000000ffb2574d (rcu_read_lock){....}, at:
debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435
2 locks held by getty/7587:
#0: 00000000b1bd6562 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000b878dc0d (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7588:
#0: 00000000d0abebef (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000163204bb (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7589:
#0: 00000000e8f197b9 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000009986261f (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7590:
#0: 00000000b40a65f3 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 0000000071ed1228 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7591:
#0: 0000000094000ffd (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000003aca5178 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7592:
#0: 0000000004aa763a (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 0000000010f9a204 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7593:
#0: 000000001d1f773a (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 0000000051afbc82 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
3 locks held by kworker/0:3/7639:
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
__write_once_size include/linux/compiler.h:220 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_data kernel/workqueue.c:617 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
#1: 000000006feeaff2 ((work_completion)(&(&ifa->dad_work)->work)){+.+.},
at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
#2: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
3 locks held by kworker/1:5/8209:
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
__write_once_size include/linux/compiler.h:220 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_data kernel/workqueue.c:617 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 00000000a9d6b9c3 ((wq_completion)"%s"("ipv6_addrconf")){+.+.}, at:
process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
#1: 0000000023ca9f75 ((work_completion)(&(&ifa->dad_work)->work)){+.+.},
at: process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
#2: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
3 locks held by kworker/1:0/29463:
#0: 000000006178e092 ((wq_completion)"events"){+.+.}, at:
__write_once_size include/linux/compiler.h:220 [inline]
#0: 000000006178e092 ((wq_completion)"events"){+.+.}, at:
arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 000000006178e092 ((wq_completion)"events"){+.+.}, at: atomic64_set
include/asm-generic/atomic-instrumented.h:40 [inline]
#0: 000000006178e092 ((wq_completion)"events"){+.+.}, at: atomic_long_set
include/asm-generic/atomic-long.h:59 [inline]
#0: 000000006178e092 ((wq_completion)"events"){+.+.}, at: set_work_data
kernel/workqueue.c:617 [inline]
#0: 000000006178e092 ((wq_completion)"events"){+.+.}, at:
set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
#0: 000000006178e092 ((wq_completion)"events"){+.+.}, at:
process_one_work+0x87e/0x1750 kernel/workqueue.c:2124
#1: 000000003ba4f6d7 (deferred_process_work){+.+.}, at:
process_one_work+0x8b4/0x1750 kernel/workqueue.c:2128
#2: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.5/1368:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.5/1375:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.5/1404:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.4/1381:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.3/1382:
#0: 00000000596fd408 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock
include/linux/fs.h:747 [inline]
#0: 00000000596fd408 (&sb->s_type->i_mutex_key#11){+.+.}, at:
__sock_release+0x89/0x2a0 net/socket.c:578
1 lock held by syz-executor.3/1385:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.3/1390:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.1/1398:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.1/1399:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.1/1405:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.0/1389:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.2/1400:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77
1 lock held by syz-executor.2/1401:
#0: 00000000da5feb96 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20
net/core/rtnetlink.c:77

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

NMI backtrace for cpu 0
CPU: 0 PID: 1036 Comm: khungtaskd Not tainted 4.19.68 #42
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+0x172/0x1f0 lib/dump_stack.c:113
nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
watchdog+0x9df/0xee0 kernel/hung_task.c:287
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 25866 Comm: kworker/u4:8 Not tainted 4.19.68 #42
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_acquire+0x49/0x3f0 kernel/locking/lockdep.c:3892
Code: f5 41 54 49 89 fc 53 65 48 8b 1c 25 40 ee 01 00 48 8d bb 7c 08 00 00
48 83 ec 20 4c 89 4d d0 48 89 fa 48 c1 ea 03 0f b6 14 02 <48> 89 f8 83 e0
07 83 c0 03 38 d0 7c 08 84 d2 0f 85 c7 02 00 00 8b
RSP: 0018:ffff88808e547c80 EFLAGS: 00000a07
RAX: dffffc0000000000 RBX: ffff8880574160c0 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88805741693c
RBP: ffff88808e547cc8 R08: 0000000000000000 R09: 0000000000000000
R10: ffffed1015d24732 R11: 0000000000000000 R12: ffffffff8879f1e0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002
FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000000a4649000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:242 [inline]
rcu_read_lock include/linux/rcupdate.h:627 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:419 [inline]
batadv_nc_worker+0x117/0x760 net/batman-adv/network-coding.c:730
process_one_work+0x989/0x1750 kernel/workqueue.c:2153
worker_thread+0x98/0xe40 kernel/workqueue.c:2296
kthread+0x354/0x420 kernel/kthread.c:246
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415


---
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Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.