INFO: task kworker/0:2:2999 blocked for more than 143 seconds. Not tainted 5.11.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:2 state:D stack:26432 pid: 2999 ppid: 2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x90c/0x21a0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:5216 __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/1657: #0: ffffffff8bd73da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6259 3 locks held by kworker/0:2/2999: #0: ffff888147d7b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888147d7b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888147d7b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888147d7b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888147d7b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888147d7b938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246 #1: ffffc90001b8fda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250 #2: ffffffff8d4590e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4570 1 lock held by in:imklog/8181: #0: ffff888012caaff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947 1 lock held by syz-executor640/8488: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1657 Comm: khungtaskd Not tainted 5.11.0-rc6-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: 8488 Comm: syz-executor640 Not tainted 5.11.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4511 [inline] RIP: 0010:__lock_acquire+0x4af/0x54f0 kernel/locking/lockdep.c:4782 Code: 0f 83 36 0c 00 00 4b 8d 04 7f 48 c1 e0 06 48 05 c0 6b 86 8f 48 ba 00 00 00 00 00 fc ff df 48 8b 0c 24 48 c1 e9 03 0f b6 14 11 <84> d2 74 09 80 fa 03 0f 8e 64 10 00 00 8b b5 80 09 00 00 85 f6 0f RSP: 0018:ffffc9000176eb10 EFLAGS: 00000802 RAX: ffffffff8f8b2100 RBX: 0000000000000001 RCX: 1ffff1100413b4a8 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f866868 RBP: ffff8880209d9bc0 R08: 0000000000000000 R09: ffffffff8f86686f R10: fffffbfff1f0cd0d R11: 0000000000000000 R12: ffff8880209da570 R13: 0000000000000003 R14: ffff888014fe6a68 R15: 0000000000000647 FS: 0000000001ae1300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd298bb8b8 CR3: 0000000026573000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5442 [inline] lock_acquire+0x1a8/0x720 kernel/locking/lockdep.c:5407 __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+0x34f/0x1460 net/sched/act_police.c:81 tcf_action_init_1+0x63b/0x990 net/sched/act_api.c:1010 tcf_action_init+0x265/0x4b0 net/sched/act_api.c:1063 tcf_action_add+0xd9/0x360 net/sched/act_api.c:1476 tc_ctl_action+0x33a/0x440 net/sched/act_api.c:1530 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5553 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: 0033:0x440329 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 00 00 90 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd298bb8d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000440329 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000005 RBP: 0000000000000000 R08: 00000000004ab000 R09: 00000000004ab000 R10: 00000000004ab000 R11: 0000000000000246 R12: 000000000007b39b R13: 00007ffd298bb900 R14: 00007ffd298bb8f0 R15: 00007ffd298bb8e4 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.402 msecs