INFO: task kworker/u4:2:51 blocked for more than 143 seconds. Not tainted 5.11.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:2 state:D stack:23600 pid: 51 ppid: 2 flags:0x00004000 Workqueue: tc_filter_workqueue tcindex_partial_destroy_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 tcindex_partial_destroy_work+0x13/0x50 net/sched/cls_tcindex.c:287 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 INFO: task kworker/0:1:8489 blocked for more than 143 seconds. Not tainted 5.11.0-rc2-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:1 state:D stack:29776 pid: 8489 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:4569 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: 3 locks held by kworker/u4:2/51: #0: ffff88814177a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88814177a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff88814177a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff88814177a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff88814177a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff88814177a938 ((wq_completion)tc_filter_workqueue){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90000f0fda8 ((work_completion)(&(rwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffffffff8c9463e8 (rtnl_mutex){+.+.}-{3:3}, at: tcindex_partial_destroy_work+0x13/0x50 net/sched/cls_tcindex.c:287 1 lock held by khungtaskd/1646: #0: ffffffff8b363820 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8203: #0: ffff888023aa8d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 3 locks held by kworker/0:1/8489: #0: ffff8881478b0d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8881478b0d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff8881478b0d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff8881478b0d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff8881478b0d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff8881478b0d38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc9000c817da8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffffffff8c9463e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4569 1 lock held by syz-executor879/8519: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1646 Comm: khungtaskd Not tainted 5.11.0-rc2-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8519 Comm: syz-executor879 Not tainted 5.11.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_read_lock_held_common kernel/rcu/update.c:110 [inline] RIP: 0010:rcu_read_lock_held_common kernel/rcu/update.c:100 [inline] RIP: 0010:rcu_read_lock_sched_held+0x25/0x70 kernel/rcu/update.c:121 Code: 00 00 00 00 00 41 54 41 bc 01 00 00 00 e8 53 44 8d 07 85 c0 75 06 44 89 e0 41 5c c3 e8 b4 72 00 00 84 c0 74 41 e8 db 87 00 00 <84> c0 74 38 be ff ff ff ff 48 c7 c7 60 37 36 8b e8 e6 42 8d 07 85 RSP: 0018:ffffc9000182ead0 EFLAGS: 00000282 RAX: 0000000000000001 RBX: 1ffff92000305d5e RCX: ffffffff81588dc8 RDX: 1ffffffff166d72e RSI: 0000000000000003 RDI: ffffffff8b36b970 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8cef548f R10: fffffbfff19dea91 R11: 0000000000000000 R12: 0000000000000001 R13: ffff888014351668 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000001508880(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff69f09500 CR3: 000000002994c000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x5c9/0x740 kernel/locking/lockdep.c:5408 __mutex_lock_common kernel/locking/mutex.c:956 [inline] __mutex_lock+0x134/0x1110 kernel/locking/mutex.c:1103 tcf_idr_check_alloc+0x78/0x3b0 net/sched/act_api.c:549 tcf_police_init+0x347/0x13a0 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 tcindex_set_parms+0x189/0x20d0 net/sched/cls_tcindex.c:342 tcindex_change+0x212/0x320 net/sched/cls_tcindex.c:546 tc_new_tfilter+0x1394/0x2120 net/sched/cls_api.c:2127 rtnetlink_rcv_msg+0x80e/0xad0 net/core/rtnetlink.c:5555 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+0x6e8/0x810 net/socket.c:2345 ___sys_sendmsg+0xf3/0x170 net/socket.c:2399 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2432 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x441719 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:00007fff69f094f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441719 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003 RBP: 00007fff69f09500 R08: 0000000100000000 R09: 0000000100000000 R10: 0000000100000000 R11: 0000000000000246 R12: 0000000000076d14 R13: 00000000004025f0 R14: 0000000000000000 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.609 msecs