INFO: task kworker/1:2:1064 blocked for more than 143 seconds. Not tainted 5.15.160-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:2 state:D stack:23768 pid: 1064 ppid: 2 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_verify_work Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376 schedule+0x11b/0x1f0 kernel/sched/core.c:6459 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6518 __mutex_lock_common+0xe34/0x25a0 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4656 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/1:2/1064: #0: ffff888024054138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900046d7d20 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffffffff8d9e7e48 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 net/ipv6/addrconf.c:4656 2 locks held by getty/3261: #0: ffff88814ad1d098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc9000209b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 1 lock held by syz-executor288/3535: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.160-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3535 Comm: syz-executor288 Not tainted 5.15.160-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:___might_sleep+0x71/0x6a0 kernel/sched/core.c:9585 Code: 41 48 c7 44 24 48 81 f4 14 8c 48 c7 44 24 50 30 1f 59 81 4c 8d 7c 24 40 49 c1 ef 03 48 b8 f1 f1 f1 f1 00 f2 f2 f2 4b 89 04 37 <43> c7 44 37 09 f2 f2 f2 00 66 43 c7 44 37 0d f3 f3 43 c6 44 37 0f RSP: 0018:ffffc900011de5a0 EFLAGS: 00000a02 RAX: f2f2f200f1f1f1f1 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 000000000000023d RDI: ffffffff8a8b1860 RBP: ffffc900011de6b0 R08: dffffc0000000000 R09: ffffc900011de780 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200023bcbc FS: 0000555556a37380(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff41692128 CR3: 000000007a81f000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __mutex_lock_common+0xd4/0x25a0 kernel/locking/mutex.c:573 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 tcf_idr_check_alloc+0xa1/0x380 net/sched/act_api.c:568 tcf_police_init+0x294/0x17c0 net/sched/act_police.c:84 tcf_action_init_1+0x50f/0x7f0 net/sched/act_api.c:1051 tcf_action_init+0x2f3/0x750 net/sched/act_api.c:1110 tcf_action_add net/sched/act_api.c:1522 [inline] tc_ctl_action+0x49b/0xd00 net/sched/act_api.c:1581 rtnetlink_rcv_msg+0x993/0xee0 net/core/rtnetlink.c:5629 netlink_rcv_skb+0x1cf/0x410 net/netlink/af_netlink.c:2508 netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline] netlink_unicast+0x7b6/0x980 net/netlink/af_netlink.c:1356 netlink_sendmsg+0xa30/0xd60 net/netlink/af_netlink.c:1924 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2431 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2485 __sys_sendmsg net/socket.c:2514 [inline] __do_sys_sendmsg net/socket.c:2523 [inline] __se_sys_sendmsg+0x19a/0x260 net/socket.c:2521 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f22addf7df9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffc4c553208 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f22addf7df9 RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000006 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.787 msecs