INFO: task kworker/1:2:3863 blocked for more than 143 seconds.
      Not tainted 5.11.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:2     state:D stack:27528 pid: 3863 ppid:     2 flags:0x00004000
Workqueue: ipv6_addrconf addrconf_verify_work
Call Trace:
 context_switch kernel/sched/core.c:4313 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5064
 schedule+0xcf/0x270 kernel/sched/core.c:5143
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5202
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x81a/0x1110 kernel/locking/mutex.c:1103
 addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Showing all locks held in the system:
1 lock held by khungtaskd/1653:
 #0: ffffffff8b373920 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254
3 locks held by kworker/1:2/3863:
 #0: ffff88802115ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88802115ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff88802115ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff88802115ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff88802115ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff88802115ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246
 #1: ffffc9000337fda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250
 #2: ffffffff8ca58da8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570
1 lock held by in:imklog/8326:
 #0: ffff8880225bcff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947
2 locks held by syz-executor669/8507:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1653 Comm: khungtaskd Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd43/0xfa0 kernel/hung_task.c:294
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8507 Comm: syz-executor669 Not tainted 5.11.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:check_memory_region+0x134/0x180 mm/kasan/generic.c:186
Code: 85 d2 75 0b 48 89 da 48 29 c2 e9 55 ff ff ff 49 39 d2 75 17 49 0f be 02 41 83 e1 07 49 39 c1 7d 0a 5b b8 01 00 00 00 5d 41 5c <c3> 44 89 c2 e8 03 f0 ff ff 5b 83 f0 01 5d 41 5c c3 48 29 c3 48 89
RSP: 0018:ffffc900013fed38 EFLAGS: 00000246
RAX: 0000000000000001 RBX: dffffc0000000000 RCX: ffffffff88fb571e
RDX: ffffed10035f6e41 RSI: 0000000000000008 RDI: ffff88801afb7200
RBP: ffffc900013feeb0 R08: 0000000000000000 R09: ffff88801afb7207
R10: ffffed10035f6e40 R11: 0000000000000000 R12: ffffc900013ff038
R13: 0000000000000001 R14: 1ffff9200027fdac R15: ffff88801afb7200
FS:  0000000001ed4880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8284b3b020 CR3: 000000002570b000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 atomic64_read include/asm-generic/atomic-instrumented.h:837 [inline]
 atomic_long_read include/asm-generic/atomic-long.h:29 [inline]
 __mutex_unlock_slowpath+0x8e/0x610 kernel/locking/mutex.c:1237
 tcf_idr_check_alloc+0x29e/0x3b0 net/sched/act_api.c:556
 tcf_police_init+0x34f/0x1460 net/sched/act_police.c:81
 tcf_action_init_1+0x1a3/0x990 net/sched/act_api.c:1013
 tcf_exts_validate+0x138/0x420 net/sched/cls_api.c:3046
 route4_set_parms net/sched/cls_route.c:393 [inline]
 route4_change+0x6d8/0x2380 net/sched/cls_route.c:512
 tc_new_tfilter+0x1394/0x2120 net/sched/cls_api.c:2127
 rtnetlink_rcv_msg+0x80e/0xad0 net/core/rtnetlink.c:5544
 netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2494
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x331/0x810 net/socket.c:2345
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2399
 __sys_sendmmsg+0x195/0x470 net/socket.c:2489
 __do_sys_sendmmsg net/socket.c:2518 [inline]
 __se_sys_sendmmsg net/socket.c:2515 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2515
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x441639
Code: e8 5c ad 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 bb 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffec3d9de18 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441639
RDX: 010efe10675dec16 RSI: 0000000020000200 RDI: 0000000000000003
RBP: 00007ffec3d9de20 R08: 0000000120080522 R09: 0000000120080522
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004a29b0
R13: 0000000000402510 R14: 0000000000000000 R15: 0000000000000000
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.635 msecs