INFO: task kworker/u4:1:21 blocked for more than 143 seconds.
      Not tainted 5.9.0-rc8-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:1    state:D stack:24456 pid:   21 ppid:     2 flags:0x00004000
Workqueue: tc_filter_workqueue tcindex_partial_destroy_work
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0xec9/0x2280 kernel/sched/core.c:4527
 schedule+0xd0/0x2a0 kernel/sched/core.c:4602
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4661
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
 tcindex_partial_destroy_work+0x13/0x50 net/sched/cls_tcindex.c:287
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Showing all locks held in the system:
3 locks held by kworker/u4:1/21:
 #0: ffff88821a941138 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88821a941138 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff88821a941138 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff88821a941138 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff88821a941138 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff88821a941138 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
 #1: ffffc90000dd7da8 ((work_completion)(&(rwork)->work)){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
 #2: ffffffff8b17a448 (rtnl_mutex){+.+.}-{3:3}, at: tcindex_partial_destroy_work+0x13/0x50 net/sched/cls_tcindex.c:287
1 lock held by khungtaskd/1172:
 #0: ffffffff8a068480 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5852
1 lock held by in:imklog/6583:
 #0: ffff8880a7f8b870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930
3 locks held by kworker/0:0/6894:
 #0: ffff888214dd9d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888214dd9d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff888214dd9d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff888214dd9d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff888214dd9d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff888214dd9d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x82b/0x1670 kernel/workqueue.c:2240
 #1: ffffc9000436fda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x85f/0x1670 kernel/workqueue.c:2244
 #2: ffffffff8b17a448 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568
1 lock held by syz-executor773/6923:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1172 Comm: khungtaskd Not tainted 5.9.0-rc8-syzkaller #0
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+0x198/0x1fd lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x223 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+0xd7d/0x1000 kernel/hung_task.c:295
 kthread+0x3b5/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6923 Comm: syz-executor773 Not tainted 5.9.0-rc8-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:find_held_lock+0xe3/0x110 kernel/locking/lockdep.c:4565
Code: 45 31 e4 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 0f b6 14 02 4c 89 f0 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 11 5b <45> 89 3e 4c 89 e0 5d 41 5c 41 5d 41 5e 41 5f c3 4c 89 f7 e8 55 45
RSP: 0018:ffffc900011f6a50 EFLAGS: 00000097
RAX: 0000000000000003 RBX: 0000000000000002 RCX: ffffc900011f6ad0
RDX: 0000000000000004 RSI: ffff88809a26c468 RDI: ffff8880a6aded70
RBP: 1ffff9200023ed52 R08: 0000000000000001 R09: ffff8880a6aded40
R10: fffffbfff16b96d1 R11: 0000000000000000 R12: ffff8880a6aded70
R13: ffff88809a26c468 R14: ffffc900011f6ad0 R15: 0000000000000001
FS:  00000000018ee880(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f20150936c0 CR3: 000000009f07d000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __lock_release kernel/locking/lockdep.c:4728 [inline]
 lock_release+0x244/0x8f0 kernel/locking/lockdep.c:5049
 __mutex_unlock_slowpath+0x81/0x610 kernel/locking/mutex.c:1228
 tcf_idr_check_alloc+0x29e/0x3b0 net/sched/act_api.c:508
 tcf_police_init+0x347/0x13a0 net/sched/act_police.c:81
 tcf_action_init_1+0x1a3/0x990 net/sched/act_api.c:993
 tcf_exts_validate+0x138/0x420 net/sched/cls_api.c:3058
 tcindex_set_parms+0x189/0x20d0 net/sched/cls_tcindex.c:342
 tcindex_change+0x203/0x2e0 net/sched/cls_tcindex.c:546
 tc_new_tfilter+0x1398/0x2130 net/sched/cls_api.c:2129
 rtnetlink_rcv_msg+0x80f/0xad0 net/core/rtnetlink.c:5554
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2489
 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:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x331/0x810 net/socket.c:2353
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407
 __sys_sendmmsg+0x195/0x480 net/socket.c:2497
 __do_sys_sendmmsg net/socket.c:2526 [inline]
 __se_sys_sendmmsg net/socket.c:2523 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2523
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x441889
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:00007fff1724c618 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441889
RDX: 04924924924924b3 RSI: 0000000020000200 RDI: 0000000000000004
RBP: 00007fff1724c620 R08: 0000000120080522 R09: 0000000120080522
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004a2c90
R13: 0000000000402760 R14: 0000000000000000 R15: 0000000000000000
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 0.000 msecs