INFO: task kworker/0:0:7 blocked for more than 143 seconds. Not tainted 5.15.159-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:0 state:D stack:24696 pid: 7 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: 3 locks held by kworker/0:0/7: #0: ffff88814ac37138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc90000cc7d20 ((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 1 lock held by khungtaskd/27: #0: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3260: #0: ffff88807f088098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002bab2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 1 lock held by syz-executor387/3528: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.159-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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3528 Comm: syz-executor387 Not tainted 5.15.159-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 RIP: 0010:hlock_class kernel/locking/lockdep.c:197 [inline] RIP: 0010:__lock_acquire+0x1211/0x1ff0 kernel/locking/lockdep.c:5009 Code: 00 00 41 8b 1f 81 e3 ff 1f 00 00 89 d8 c1 e8 06 48 8d 3c c5 c0 80 bf 8f be 08 00 00 00 e8 87 68 67 00 48 0f a3 1d df bc 5c 0e <73> 1b 48 8d 04 5b 48 c1 e0 06 48 8d 98 c0 df 8e 8f 48 ba 00 00 00 RSP: 0018:ffffc90002d76480 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000669 RCX: ffffffff8162c3d9 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fbf8188 RBP: 83e8343fbcdf6e0b R08: dffffc0000000000 R09: fffffbfff1f7f032 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001 R13: ffff888024370ae8 R14: ffff888024370000 R15: ffff888024370b38 FS: 0000555557262380(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fa3d505680 CR3: 0000000022f27000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __mutex_lock_common+0x1da/0x25a0 kernel/locking/mutex.c:596 __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:2505 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: 0033:0x7f8f5d42bdf9 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:00007ffd12600738 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8f5d42bdf9 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: 2.676 msecs