Extracting prog: 10m19.261087564s
Minimizing prog: 47m29.557603824s
Simplifying prog options: 16m34.990989648s
Extracting C: 4m6.161872916s
Simplifying C: 0s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 6m0s
testing program (duration=6m0s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r1, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program crashed: INFO: task hung in addrconf_dad_work
program crashed: INFO: task hung in addrconf_dad_work
single: successfully extracted reproducer
found reproducer with 4 syscalls
minimizing guilty program
testing program (duration=7m45.710892483s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX
detailed listing:
executing program 0:
socket$netlink(0x10, 0x3, 0x0)
r0 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r0, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})

program did not crash
testing program (duration=7m45.710892483s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program did not crash
testing program (duration=7m45.710892483s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(0xffffffffffffffff, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program did not crash
testing program (duration=7m45.710892483s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r0, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(0xffffffffffffffff, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program did not crash
testing program (duration=7m45.710892483s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r1, 0x8933, 0x0)
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program did not crash
testing program (duration=7m45.710892483s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r1, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=7m45.710892483s, {Threaded:true Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
program crashed: INFO: task hung in inet_rtm_newaddr
a never seen crash title: INFO: task hung in inet_rtm_newaddr, ignore
simplifying guilty program options
testing program (duration=7m45.710892483s, {Threaded:false Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r1, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program crashed: INFO: task hung in addrconf_dad_work
extracting C reproducer
testing compiled C program (duration=7m45.710892483s, {Threaded:false Repeat:true RepeatTimes:0 Procs:6 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
program crashed: INFO: task hung in inet6_rtm_newaddr
a never seen crash title: INFO: task hung in inet6_rtm_newaddr, ignore
testing program (duration=7m45.710892483s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r1, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program crashed: INFO: task hung in addrconf_dad_work
extracting C reproducer
testing compiled C program (duration=7m45.710892483s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
program crashed: INFO: task hung in reg_check_chans_work
a never seen crash title: INFO: task hung in reg_check_chans_work, ignore
testing program (duration=7m45.710892483s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r1, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program crashed: INFO: task hung in reg_check_chans_work
validation run: crashed=true
testing program (duration=7m45.710892483s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r1, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program crashed: INFO: task hung in inet_rtm_newaddr
validation run: crashed=true
testing program (duration=7m45.710892483s, {Threaded:false Repeat:true RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:true Wifi:true IEEE802154:true Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): socket$netlink-socket$nl_route-ioctl$sock_SIOCGIFINDEX-ioctl$sock_SIOCBRDELBR
detailed listing:
executing program 0:
r0 = socket$netlink(0x10, 0x3, 0x0)
r1 = socket$nl_route(0x10, 0x3, 0x0)
ioctl$sock_SIOCGIFINDEX(r1, 0x8933, &(0x7f0000000000)={'veth1_to_bridge\x00'})
ioctl$sock_SIOCBRDELBR(r0, 0x89a2, &(0x7f0000000000)='bridge0\x00')

program crashed: INFO: task hung in reg_check_chans_work
validation run: crashed=true
reproducing took 1h31m42.215901702s
repro crashed as (corrupted=false):
INFO: task kworker/0:3:1355 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3     state:D stack:22816 pid:1355  tgid:1355  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient reg_check_chans_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 class_wiphy_constructor include/net/cfg80211.h:6363 [inline]
 reg_leave_invalid_chans net/wireless/reg.c:2441 [inline]
 reg_check_chans_work+0x156/0xf00 net/wireless/reg.c:2456
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
INFO: task dhcpcd:5028 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:20152 pid:5028  tgid:5028  ppid:5027   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 inet6_rtm_deladdr+0x20f/0x330 net/ipv6/addrconf.c:4799
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x820 net/socket.c:2592
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0782d46407
RSP: 002b:00007ffd1ea21510 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0782cbc740 RCX: 00007f0782d46407
RDX: 0000000000000000 RSI: 00007ffd1ea356f0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd1ea45920
R13: 00007f0782cbc6c8 R14: 000000000000002c R15: 00007ffd1ea356f0
 </TASK>
INFO: task kworker/u4:4:5451 blocked for more than 152 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:4    state:D stack:24952 pid:5451  tgid:5451  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863

final repro crashed as (corrupted=false):
INFO: task kworker/0:3:1355 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:3     state:D stack:22816 pid:1355  tgid:1355  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_power_efficient reg_check_chans_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 class_wiphy_constructor include/net/cfg80211.h:6363 [inline]
 reg_leave_invalid_chans net/wireless/reg.c:2441 [inline]
 reg_check_chans_work+0x156/0xf00 net/wireless/reg.c:2456
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
INFO: task dhcpcd:5028 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:20152 pid:5028  tgid:5028  ppid:5027   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 inet6_rtm_deladdr+0x20f/0x330 net/ipv6/addrconf.c:4799
 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x820 net/socket.c:2592
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0782d46407
RSP: 002b:00007ffd1ea21510 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f0782cbc740 RCX: 00007f0782d46407
RDX: 0000000000000000 RSI: 00007ffd1ea356f0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd1ea45920
R13: 00007f0782cbc6c8 R14: 000000000000002c R15: 00007ffd1ea356f0
 </TASK>
INFO: task kworker/u4:4:5451 blocked for more than 152 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:4    state:D stack:24952 pid:5451  tgid:5451  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863