[ OK ] Started Getty on tty2. [ OK ] Started Serial Getty on ttyS0. [ OK ] Started Getty on tty1. [ OK ] Started getty on tty2-tty6 if dbus and logind are not available. [ OK ] Started OpenBSD Secure Shell server. Debian GNU/Linux 9 syzkaller ttyS0 syzkaller login: [ 58.976772][ T8340] sshd (8340) used greatest stack depth: 22808 bytes left Warning: Permanently added '10.128.10.2' (ECDSA) to the list of known hosts. executing program executing program [ 505.901740][ T8487] IPVS: ftp: loaded support on port[0] = 21 [ 721.441356][ T1653] INFO: task kworker/0:1:8479 blocked for more than 143 seconds. [ 721.449301][ T1653] Not tainted 5.11.0-rc2-syzkaller #0 [ 721.458061][ T1653] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 721.467811][ T1653] task:kworker/0:1 state:D stack:29224 pid: 8479 ppid: 2 flags:0x00004000 [ 721.478162][ T1653] Workqueue: ipv6_addrconf addrconf_verify_work [ 721.485659][ T1653] Call Trace: [ 721.489026][ T1653] __schedule+0x90c/0x21a0 [ 721.495012][ T1653] ? io_schedule_timeout+0x140/0x140 [ 721.500347][ T1653] ? _raw_spin_unlock_irq+0x1f/0x40 [ 721.507228][ T1653] ? lockdep_hardirqs_on+0x79/0x100 [ 721.513540][ T1653] schedule+0xcf/0x270 [ 721.517670][ T1653] schedule_preempt_disabled+0xf/0x20 [ 721.524589][ T1653] __mutex_lock+0x81a/0x1110 [ 721.529223][ T1653] ? addrconf_verify_work+0xa/0x20 [ 721.537086][ T1653] ? mutex_lock_io_nested+0xf60/0xf60 [ 721.544022][ T1653] ? lock_release+0x710/0x710 [ 721.548868][ T1653] ? lock_downgrade+0x6d0/0x6d0 [ 721.555235][ T1653] addrconf_verify_work+0xa/0x20 [ 721.560485][ T1653] process_one_work+0x98d/0x15f0 [ 721.567194][ T1653] ? pwq_dec_nr_in_flight+0x320/0x320 [ 721.573682][ T1653] ? rwlock_bug.part.0+0x90/0x90 [ 721.578673][ T1653] ? _raw_spin_lock_irq+0x41/0x50 [ 721.585497][ T1653] worker_thread+0x64c/0x1120 [ 721.590253][ T1653] ? __kthread_parkme+0x13f/0x1e0 [ 721.596931][ T1653] ? process_one_work+0x15f0/0x15f0 [ 721.603362][ T1653] kthread+0x3b1/0x4a0 [ 721.607484][ T1653] ? kthread_create_worker_on_cpu+0xf0/0xf0 [ 721.614917][ T1653] ret_from_fork+0x1f/0x30 [ 721.619737][ T1653] [ 721.619737][ T1653] Showing all locks held in the system: [ 721.629167][ T1653] 1 lock held by khungtaskd/1653: [ 721.636189][ T1653] #0: ffffffff8b363860 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 [ 721.647241][ T1653] 1 lock held by in:imklog/8182: [ 721.654850][ T1653] #0: ffff88801430c370 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 [ 721.666414][ T1653] 3 locks held by kworker/0:1/8479: [ 721.672599][ T1653] #0: ffff88802109ad38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 [ 721.684895][ T1653] #1: ffffc90000cd7da8 ((addr_chk_work).work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 [ 721.696353][ T1653] #2: ffffffff8c9465e8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0xa/0x20 [ 721.707318][ T1653] 1 lock held by syz-executor860/8509: [ 721.713827][ T1653] [ 721.716168][ T1653] ============================================= [ 721.716168][ T1653] [ 721.726242][ T1653] NMI backtrace for cpu 0 [ 721.730612][ T1653] CPU: 0 PID: 1653 Comm: khungtaskd Not tainted 5.11.0-rc2-syzkaller #0 [ 721.738959][ T1653] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 721.749057][ T1653] Call Trace: [ 721.752358][ T1653] dump_stack+0x107/0x163 [ 721.756766][ T1653] nmi_cpu_backtrace.cold+0x44/0xd7 [ 721.762017][ T1653] ? lapic_can_unplug_cpu+0x80/0x80 [ 721.767321][ T1653] nmi_trigger_cpumask_backtrace+0x1b3/0x230 [ 721.773401][ T1653] watchdog+0xd43/0xfa0 [ 721.777652][ T1653] ? reset_hung_task_detector+0x30/0x30 [ 721.783239][ T1653] kthread+0x3b1/0x4a0 [ 721.787348][ T1653] ? kthread_create_worker_on_cpu+0xf0/0xf0 [ 721.793281][ T1653] ret_from_fork+0x1f/0x30 [ 721.797970][ T1653] Sending NMI from CPU 0 to CPUs 1: [ 721.805013][ C1] NMI backtrace for cpu 1 [ 721.805026][ C1] CPU: 1 PID: 8509 Comm: syz-executor860 Not tainted 5.11.0-rc2-syzkaller #0 [ 721.805036][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 721.805046][ C1] RIP: 0010:lock_is_held_type+0xc2/0x100 [ 721.805057][ C1] Code: 03 44 39 f0 41 0f 94 c4 48 c7 c7 80 a1 4b 89 e8 44 0b 00 00 b8 ff ff ff ff 65 0f c1 05 27 58 16 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 [ 721.805073][ C1] RSP: 0018:ffffc900092aeb00 EFLAGS: 00000202 [ 721.805087][ C1] RAX: 0000000000000001 RBX: 0000000000000001 RCX: 1ffffffff19df0e3 [ 721.805096][ C1] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 721.805105][ C1] RBP: ffffffff8b363800 R08: ffffffff8711e668 R09: ffff8880247cd407 [ 721.805114][ C1] R10: ffffed10048f9a80 R11: 0000000000000000 R12: 0000000000000000 [ 721.805122][ C1] R13: ffff88801acf5cc8 R14: 00000000ffffffff R15: ffff88801acf5cc8 [ 721.805131][ C1] FS: 0000000001986880(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000 [ 721.805140][ C1] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 721.805148][ C1] CR2: 0000000020000280 CR3: 0000000017f2c000 CR4: 00000000001506e0 [ 721.805157][ C1] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 721.805166][ C1] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 721.805173][ C1] Call Trace: [ 721.805178][ C1] ___might_sleep+0x202/0x2c0 [ 721.805184][ C1] __mutex_lock+0xa9/0x1110 [ 721.805189][ C1] ? tcf_idr_check_alloc+0x78/0x3b0 [ 721.805195][ C1] ? mutex_lock_io_nested+0xf60/0xf60 [ 721.805202][ C1] ? __mutex_unlock_slowpath+0xe2/0x610 [ 721.805208][ C1] ? wait_for_completion_io+0x260/0x260 [ 721.805215][ C1] tcf_idr_check_alloc+0x78/0x3b0 [ 721.805221][ C1] tcf_police_init+0x347/0x13a0 [ 721.805226][ C1] ? tcf_police_cleanup+0x60/0x60 [ 721.805232][ C1] ? find_held_lock+0x2d/0x110 [ 721.805238][ C1] ? tc_lookup_action_n+0xcd/0xf0 [ 721.805244][ C1] ? lockdep_hardirqs_on_prepare+0x400/0x400 [ 721.805251][ C1] ? __kernel_text_address+0x9/0x30 [ 721.805257][ C1] tcf_action_init_1+0x1a3/0x990 [ 721.805263][ C1] ? tcf_action_dump_old+0x80/0x80 [ 721.805269][ C1] ? find_held_lock+0x2d/0x110 [ 721.805275][ C1] ? pcpu_alloc+0x1239/0x16f0 [ 721.805281][ C1] ? lock_downgrade+0x6d0/0x6d0 [ 721.805287][ C1] tcf_exts_validate+0x138/0x420 [ 721.805292][ C1] ? tcf_exts_destroy+0xc0/0xc0 [ 721.805298][ C1] ? __mutex_unlock_slowpath+0xe2/0x610 [ 721.805313][ C1] ? wait_for_completion_io+0x260/0x260 [ 721.805320][ C1] u32_set_parms+0xb9/0xc60 [ 721.805326][ C1] ? __sanitizer_cov_trace_const_cmp1+0x22/0x80 [ 721.805334][ C1] ? u32_bind_class+0x2c0/0x2c0 [ 721.805340][ C1] u32_change+0x1f13/0x3000 [ 721.805346][ C1] ? u32_dump+0x1030/0x1030 [ 721.805352][ C1] ? blackhole_dequeue+0x10/0x10 [ 721.805358][ C1] ? u32_lookup_ht+0x1d0/0x1d0 [ 721.805365][ C1] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 721.805372][ C1] ? tc_new_tfilter+0x132a/0x2120 [ 721.805379][ C1] tc_new_tfilter+0x1394/0x2120 [ 721.805385][ C1] ? u32_dump+0x1030/0x1030 [ 721.805391][ C1] ? tc_del_tfilter+0x15b0/0x15b0 [ 721.805398][ C1] ? tc_del_tfilter+0x15b0/0x15b0 [ 721.805404][ C1] rtnetlink_rcv_msg+0x80e/0xad0 [ 721.805411][ C1] ? rtnetlink_put_metrics+0x510/0x510 [ 721.805418][ C1] netlink_rcv_skb+0x153/0x420 [ 721.805424][ C1] ? rtnetlink_put_metrics+0x510/0x510 [ 721.805431][ C1] ? netlink_ack+0xaa0/0xaa0 [ 721.805437][ C1] ? netlink_deliver_tap+0x227/0xb70 [ 721.805443][ C1] netlink_unicast+0x533/0x7d0 [ 721.805450][ C1] ? netlink_attachskb+0x870/0x870 [ 721.805456][ C1] ? _copy_from_iter_full+0x275/0x850 [ 721.805463][ C1] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 721.805471][ C1] ? __phys_addr_symbol+0x2c/0x70 [ 721.805478][ C1] ? __sanitizer_cov_trace_cmp8+0x1d/0x70 [ 721.805490][ C1] ? __check_object_size+0x171/0x3f0 [ 721.805496][ C1] netlink_sendmsg+0x856/0xd90 [ 721.805502][ C1] ? netlink_unicast+0x7d0/0x7d0 [ 721.805509][ C1] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 721.805516][ C1] ? netlink_unicast+0x7d0/0x7d0 [ 721.805523][ C1] sock_sendmsg+0xcf/0x120 [ 721.805528][ C1] ____sys_sendmsg+0x331/0x810 [ 721.805535][ C1] ? kernel_sendmsg+0x50/0x50 [ 721.805541][ C1] ? do_recvmmsg+0x6c0/0x6c0 [ 721.805546][ C1] ? __lock_acquire+0x16b7/0x5500 [ 721.805551][ C1] ___sys_sendmsg+0xf3/0x170 [ 721.805557][ C1] ? sendmsg_copy_msghdr+0x160/0x160 [ 721.805561][ C1] ? find_held_lock+0x2d/0x110 [ 721.805564][ C1] ? __might_fault+0xd3/0x180 [ 721.805567][ C1] ? lock_downgrade+0x6d0/0x6d0 [ 721.805570][ C1] __sys_sendmmsg+0x195/0x470 [ 721.805573][ C1] ? __ia32_sys_sendmsg+0xb0/0xb0 [ 721.805577][ C1] ? __sanitizer_cov_trace_const_cmp8+0x1d/0x70 [ 721.805581][ C1] ? sockfd_lookup_light+0xc5/0x180 [ 721.805585][ C1] ? __sys_sendmsg+0x10c/0x1b0 [ 721.805588][ C1] ? __sys_sendmsg_sock+0xb0/0xb0 [ 721.805592][ C1] ? __sanitizer_cov_trace_const_cmp4+0x1c/0x70 [ 721.805595][ C1] __x64_sys_sendmmsg+0x99/0x100 [ 721.805599][ C1] ? syscall_enter_from_user_mode+0x1d/0x50 [ 721.805603][ C1] do_syscall_64+0x2d/0x70 [ 721.805606][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 721.805610][ C1] RIP: 0033:0x4417b9 [ 721.805616][ C1] 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 [ 721.805626][ C1] RSP: 002b:00007ffd15233138 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 [ 721.805634][ C1] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004417b9 [ 721.805640][ C1] RDX: 010efe10675dec16 RSI: 0000000020000200 RDI: 0000000000000003 [ 721.805645][ C1] RBP: 00007ffd15233140 R08: 0000000100000000 R09: 0000000100000000 [ 721.805650][ C1] R10: 0000000000000000 R11: 0000000000000246 R12: 000000000007b85e [ 721.805656][ C1] R13: 0000000000402690 R14: 0000000000000000 R15: 0000000000000000 [ 721.805662][ C1] INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.668 msecs [ 721.825603][ T1653] Kernel panic - not syncing: hung_task: blocked tasks [ 722.404673][ T1653] CPU: 0 PID: 1653 Comm: khungtaskd Not tainted 5.11.0-rc2-syzkaller #0 [ 722.413023][ T1653] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 722.423102][ T1653] Call Trace: [ 722.426400][ T1653] dump_stack+0x107/0x163 [ 722.430767][ T1653] panic+0x306/0x73d [ 722.434737][ T1653] ? __warn_printk+0xf3/0xf3 [ 722.439365][ T1653] ? lapic_can_unplug_cpu+0x80/0x80 [ 722.444589][ T1653] ? preempt_schedule_thunk+0x16/0x18 [ 722.449990][ T1653] ? nmi_trigger_cpumask_backtrace+0x196/0x230 [ 722.456348][ T1653] ? watchdog.cold+0x5/0x158 [ 722.461026][ T1653] watchdog.cold+0x16/0x158 [ 722.465607][ T1653] ? reset_hung_task_detector+0x30/0x30 [ 722.471182][ T1653] kthread+0x3b1/0x4a0 [ 722.475538][ T1653] ? kthread_create_worker_on_cpu+0xf0/0xf0 [ 722.481460][ T1653] ret_from_fork+0x1f/0x30 [ 722.486514][ T1653] Kernel Offset: disabled [ 722.490870][ T1653] Rebooting in 86400 seconds..