[v5.15] INFO: task hung in rtnl_lock (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 83655231580b Linux 5.15.159
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14ba0392980000
kernel config: https://syzkaller.appspot.com/x/.config?x=c49fc0ce9b46e64b
dashboard link: https://syzkaller.appspot.com/bug?extid=3a7ea61612e7685fc7f2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/faa8b26e9d92/disk-83655231.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dacb199b57cf/vmlinux-83655231.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d7c5b8943497/Image-83655231.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3a7ea6...@syzkaller.appspotmail.com

INFO: task kworker/u4:0:9 blocked for more than 143 seconds.
Not tainted 5.15.159-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:0 state:D stack: 0 pid: 9 ppid: 2 flags:0x00000008
Workqueue: events_power_efficient crda_timeout_work
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6376
schedule+0x11c/0x1c8 kernel/sched/core.c:6459
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72
crda_timeout_work+0x1c/0x68 net/wireless/reg.c:537
process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
worker_thread+0x910/0x1034 kernel/workqueue.c:2457
kthread+0x37c/0x45c kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
INFO: task kworker/u4:5:597 blocked for more than 143 seconds.
Not tainted 5.15.159-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:5 state:D stack: 0 pid: 597 ppid: 2 flags:0x00000008
Workqueue: netns cleanup_net
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6376
schedule+0x11c/0x1c8 kernel/sched/core.c:6459
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72
netdev_run_todo+0x90c/0xae0 net/core/dev.c:10655
rtnl_unlock+0x14/0x20 net/core/rtnetlink.c:112
default_device_exit_batch+0x4c4/0x520 net/core/dev.c:11627
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x5e0/0x9bc net/core/net_namespace.c:599
process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
worker_thread+0x910/0x1034 kernel/workqueue.c:2457
kthread+0x37c/0x45c kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
INFO: task syz-executor.2:5017 blocked for more than 143 seconds.
Not tainted 5.15.159-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2 state:D stack: 0 pid: 5017 ppid: 4601 flags:0x00000005
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6376
schedule+0x11c/0x1c8 kernel/sched/core.c:6459
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5647
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356
netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
____sys_sendmsg+0x584/0x870 net/socket.c:2431
___sys_sendmsg+0x214/0x294 net/socket.c:2485
__sys_sendmsg net/socket.c:2514 [inline]
__do_sys_sendmsg net/socket.c:2523 [inline]
__se_sys_sendmsg net/socket.c:2521 [inline]
__arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2521
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
INFO: task syz-executor.3:5028 blocked for more than 143 seconds.
Not tainted 5.15.159-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3 state:D stack: 0 pid: 5028 ppid: 4056 flags:0x00000005
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6376
schedule+0x11c/0x1c8 kernel/sched/core.c:6459
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5647
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356
netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
____sys_sendmsg+0x584/0x870 net/socket.c:2431
___sys_sendmsg+0x214/0x294 net/socket.c:2485
__sys_sendmmsg+0x23c/0x648 net/socket.c:2571
__do_sys_sendmmsg net/socket.c:2600 [inline]
__se_sys_sendmmsg net/socket.c:2597 [inline]
__arm64_sys_sendmmsg+0xa0/0xbc net/socket.c:2597
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
INFO: task syz-executor.4:5062 blocked for more than 143 seconds.
Not tainted 5.15.159-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack: 0 pid: 5062 ppid: 4445 flags:0x00000005
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6376
schedule+0x11c/0x1c8 kernel/sched/core.c:6459
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
rtnl_lock net/core/rtnetlink.c:72 [inline]
rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
netlink_rcv_skb+0x20c/0x3b8 net/netlink/af_netlink.c:2505
rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:5647
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x664/0x938 net/netlink/af_netlink.c:1356
netlink_sendmsg+0x844/0xb38 net/netlink/af_netlink.c:1924
sock_sendmsg_nosec net/socket.c:704 [inline]
__sock_sendmsg net/socket.c:716 [inline]
____sys_sendmsg+0x584/0x870 net/socket.c:2431
___sys_sendmsg+0x214/0x294 net/socket.c:2485
__sys_sendmsg net/socket.c:2514 [inline]
__do_sys_sendmsg net/socket.c:2523 [inline]
__se_sys_sendmsg net/socket.c:2521 [inline]
__arm64_sys_sendmsg+0x1ac/0x25c net/socket.c:2521
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584
INFO: task syz-executor.1:5090 blocked for more than 143 seconds.
Not tainted 5.15.159-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1 state:D stack: 0 pid: 5090 ppid: 4537 flags:0x0000000d
Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6376
schedule+0x11c/0x1c8 kernel/sched/core.c:6459
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72
register_nexthop_notifier+0x88/0x218 net/ipv4/nexthop.c:3606
vxlan_init_net+0xc8/0xdc drivers/net/vxlan/vxlan_core.c:4728
ops_init+0x2e4/0x54c net/core/net_namespace.c:138
setup_net+0x330/0x988 net/core/net_namespace.c:332
copy_net_ns+0x2f8/0x5e0 net/core/net_namespace.c:476
create_new_namespaces+0x330/0x61c kernel/nsproxy.c:110
unshare_nsproxy_namespaces+0x108/0x158 kernel/nsproxy.c:226
ksys_unshare+0x45c/0x874 kernel/fork.c:3101
__do_sys_unshare kernel/fork.c:3175 [inline]
__se_sys_unshare kernel/fork.c:3173 [inline]
__arm64_sys_unshare+0x3c/0x50 kernel/fork.c:3173
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608
el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626
el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Showing all locks held in the system:
3 locks held by kworker/u4:0/9:
#0: ffff0000c002a138 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
#1: ffff800018967c00 ((crda_timeout).work){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
#2: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72
3 locks held by kworker/1:0/21:
#0: ffff0000d2768d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
#1: ffff800018a37c00 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
#2: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72
1 lock held by khungtaskd/27:
#0: ffff800014b214a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311
3 locks held by kworker/u4:1/136:
#0: ffff0000c002a138 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
#1: ffff80001a3a7c00 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
#2: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72
4 locks held by kworker/u4:5/597:
#0: ffff0000c038c138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
#1: ffff80001d7b7c00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285
#2: ffff800016a3b4d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf4/0x9bc net/core/net_namespace.c:561
#3: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72
2 locks held by getty/3730:
#0: ffff0000d327c098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
#1: ffff80001a32e2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
1 lock held by syz-executor.2/5017:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.0/5018:
1 lock held by syz-executor.3/5028:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.4/5062:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
2 locks held by syz-executor.1/5090:
#0: ffff800016a3b4d0 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2d8/0x5e0 net/core/net_namespace.c:472
#1: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72
1 lock held by syz-executor.2/5101:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.0/5104:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.3/5106:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.4/5109:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.1/5114:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.2/5122:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.0/5123:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.3/5124:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.4/5134:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626
1 lock held by syz-executor.1/5139:
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0xa2c/0xdac net/core/rtnetlink.c:5626

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



---
This report 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 issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 83655231580b Linux 5.15.159
git tree: linux-5.15.y

console output: https://syzkaller.appspot.com/x/log.txt?x=14135748980000

kernel config: https://syzkaller.appspot.com/x/.config?x=c49fc0ce9b46e64b
dashboard link: https://syzkaller.appspot.com/bug?extid=3a7ea61612e7685fc7f2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12903f6c980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14957244980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/faa8b26e9d92/disk-83655231.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/dacb199b57cf/vmlinux-83655231.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d7c5b8943497/Image-83655231.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+3a7ea6...@syzkaller.appspotmail.com

INFO: task kworker/0:2:1955 blocked for more than 143 seconds.

Not tainted 5.15.159-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:kworker/0:2 state:D stack: 0 pid: 1955 ppid: 2 flags:0x00000008
Workqueue: ipv6_addrconf addrconf_verify_work

Call trace:
__switch_to+0x308/0x5e8 arch/arm64/kernel/process.c:518
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0xf10/0x1e48 kernel/sched/core.c:6376
schedule+0x11c/0x1c8 kernel/sched/core.c:6459
schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6518
__mutex_lock_common+0xba0/0x2154 kernel/locking/mutex.c:669
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0xa4/0xf8 kernel/locking/mutex.c:743
rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72

addrconf_verify_work+0x14/0x28 net/ipv6/addrconf.c:4656

process_one_work+0x790/0x11b8 kernel/workqueue.c:2310
worker_thread+0x910/0x1034 kernel/workqueue.c:2457
kthread+0x37c/0x45c kernel/kthread.c:334
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

Showing all locks held in the system:

1 lock held by khungtaskd/27:
#0: ffff800014b214a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:311

3 locks held by kworker/0:2/1955:
#0: ffff0000d297ed38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x66c/0x11b8 kernel/workqueue.c:2283
#1: ffff800021f37c00 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x6ac/0x11b8 kernel/workqueue.c:2285

#2: ffff800016a46ca8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:72

2 locks held by getty/3741:
#0: ffff0000d4271098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x40/0x50 drivers/tty/tty_ldsem.c:340
#1: ffff80001a36b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1204 drivers/tty/n_tty.c:2158
1 lock held by syz-executor275/4005:

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



---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.