INFO: task kworker/0:1:8444 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:1 state:D stack:29768 pid: 8444 ppid: 2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch kernel/sched/core.c:3774 [inline] __schedule+0x893/0x2130 kernel/sched/core.c:4523 schedule+0xcf/0x270 kernel/sched/core.c:4601 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4660 __mutex_lock_common kernel/locking/mutex.c:1033 [inline] __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103 addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418 kthread+0x3af/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/1655: #0: ffffffff8b337820 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6252 1 lock held by in:imklog/8146: #0: ffff88801ef9aaf0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932 3 locks held by kworker/0:1/8444: #0: ffff888147a41538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888147a41538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline] #0: ffff888147a41538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline] #0: ffff888147a41538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline] #0: ffff888147a41538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline] #0: ffff888147a41538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x821/0x15a0 kernel/workqueue.c:2243 #1: ffffc90000e9fda8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x854/0x15a0 kernel/workqueue.c:2247 #2: ffffffff8c928588 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4568 2 locks held by syz-executor297/8473: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1655 Comm: khungtaskd Not tainted 5.10.0-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:77 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:118 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+0x3af/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: 8473 Comm: syz-executor297 Not tainted 5.10.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lock_is_held_type+0xc2/0x100 kernel/locking/lockdep.c:5479 Code: 03 44 39 f0 41 0f 94 c4 48 c7 c7 c0 5e 4b 89 e8 d4 0b 00 00 b8 ff ff ff ff 65 0f c1 05 57 67 1c 77 83 f8 01 75 23 ff 34 24 9d <48> 83 c4 08 44 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 e4 eb RSP: 0018:ffffc900016beb50 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 1ffffffff19d9d4b RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffffff8b337760 R08: ffffffff87119fb8 R09: ffff888021809207 R10: ffffed1004301240 R11: 0000000000000000 R12: 0000000000000000 R13: ffff88801487a350 R14: 00000000ffffffff R15: ffff88801487a350 FS: 0000000000000000(0000) GS:ffff8880b9f00000(0063) knlGS:000000000989d840 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00007f691c03f0f8 CR3: 00000000112cc000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:271 [inline] ___might_sleep+0x236/0x2b0 kernel/sched/core.c:7264 __mutex_lock_common kernel/locking/mutex.c:935 [inline] __mutex_lock+0xa9/0x10e0 kernel/locking/mutex.c:1103 tcf_idr_check_alloc+0x78/0x3b0 net/sched/act_api.c:501 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 rsvp_change+0x291/0x27a0 net/sched/cls_rsvp.h:502 tc_new_tfilter+0x1398/0x2130 net/sched/cls_api.c:2129 rtnetlink_rcv_msg+0x80e/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: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+0x292/0x470 net/socket.c:2490 __compat_sys_sendmmsg net/compat.c:361 [inline] __do_compat_sys_sendmmsg net/compat.c:368 [inline] __se_compat_sys_sendmmsg net/compat.c:365 [inline] __ia32_compat_sys_sendmmsg+0x9b/0x100 net/compat.c:365 do_syscall_32_irqs_on arch/x86/entry/common.c:78 [inline] __do_fast_syscall_32+0x56/0x80 arch/x86/entry/common.c:137 do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:160 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7ff3549 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000ff8a4b4c EFLAGS: 00000296 ORIG_RAX: 0000000000000159 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000020000200 RDX: 00000000924926d3 RSI: 0000000000000000 RDI: 0000000000000010 RBP: 0000000000080002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.398 msecs