INFO: task syz.1.1965:15662 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.1965      state:D stack:28760 pid:15662 tgid:15659 ppid:15287  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x1821/0x5740
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 rwsem_down_read_slowpath+0x6d9/0x940
 down_read+0x99/0x2e0
 super_lock+0x2d6/0x3d0
 user_get_super+0xc8/0x120
 __se_sys_quotactl+0x540/0x9e0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b9f79ce59
RSP: 002b:00007f7b9d9d5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000b3
RAX: ffffffffffffffda RBX: 00007f7b9fa16180 RCX: 00007f7b9f79ce59
RDX: 0000000000000000 RSI: 00002000000003c0 RDI: ffffffff80000800
RBP: 00007f7b9f832d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000540 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b9fa16218 R14: 00007f7b9fa16180 R15: 00007fffdbe54ce8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by kworker/u9:3/63:
 #0: ffff88812103aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150
 #1: ffff888121024588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
3 locks held by kworker/u10:5/1111:
 #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90007327c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60
2 locks held by getty/5438:
 #0: ffff88816b0b30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900034732e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by sshd/5534:
3 locks held by kworker/u8:3/5670:
 #0: ffff888112164140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc9000682fc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0
3 locks held by syz-executor/11342:
2 locks held by syz-executor/11937:
2 locks held by syz-executor/12954:
3 locks held by syz-executor/13185:
7 locks held by kworker/u8:5/15309:
 #0: ffff8881012b5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860
 #1: ffffc90004f87c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860
 #2: ffffffff8fdc2628 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800
 #3: ffff88811c4c4128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420
 #4: ffff88811477d258 (&devlink->lock_key#36){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420
 #5: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x16b/0x7f0
 #6: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz.1.1965/15662:
 #0: ffff888112b9e0d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.7.2005/15808:
 #0: ffff8881169aa0d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x289/0x3d0
1 lock held by syz.4.2063/16230:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.2063/16232:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.2063/16234:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.2063/16235:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.2063/16236:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.2063/16237:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.2063/16238:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.4.2063/16239:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz.5.2145/17029:
 #0: ffff88816bdf00d8 (&type->s_umount_key#91){++++}-{4:4}, at: super_lock+0x2d6/0x3d0
1 lock held by syz-executor/17294:
 #0: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770
1 lock held by syz-executor/17420:
 #0: ffffffff8fdd1300 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x389/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5670 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:rcu_is_watching+0x5e/0xb0
Code: 03 42 80 3c 38 00 74 08 4c 89 f7 e8 9c 26 86 00 48 c7 c3 d8 a9 3a 93 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 34 <8b> 03 65 ff 0d c9 91 8e 11 74 11 83 e0 04 c1 e8 02 5b 41 5e 41 5f
RSP: 0018:ffffc9000682ed98 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff8881210339d8 RCX: 0000000080000202
RDX: ffffc9000682ee01 RSI: ffffffff8c28b640 RDI: ffffffff8c28b600
RBP: dffffc0000000000 R08: ffffc9000682f770 R09: 0000000000000000
R10: ffffc9000682eed8 R11: fffff52000d05ddd R12: ffffc9000682f780
R13: ffffc90006828000 R14: ffffffff8e26b790 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88818dc89000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005566ade88000 CR3: 0000000116140000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 unwind_next_frame+0x1b76/0x2550
 arch_stack_walk+0x11b/0x150
 stack_trace_save+0xa9/0x100
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_node_noprof+0x384/0x690
 __alloc_skb+0x27d/0x7d0
 inet6_rt_notify+0x170/0x470
 fib6_add_rt2node+0x1889/0x3940
 fib6_add+0x8e7/0x18c0
 ip6_ins_rt+0xd6/0x140
 __ipv6_ifa_notify+0x4e8/0xc60
 addrconf_dad_completed+0x19b/0xe60
 addrconf_dad_work+0xc5e/0x14c0
 process_scheduled_works+0xb5d/0x1860
 worker_thread+0xa53/0xfc0
 kthread+0x389/0x470
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
