[....] Starting periodic command scheduler: cron[?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[ 13.412394] random: sshd: uninitialized urandom read (32 bytes read) [?25l[?1c7[1G[[32m ok [39;49m8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 16.319791] random: sshd: uninitialized urandom read (32 bytes read) [ 16.642153] random: sshd: uninitialized urandom read (32 bytes read) [ 17.347560] random: sshd: uninitialized urandom read (32 bytes read) [ 17.822047] random: sshd: uninitialized urandom read (32 bytes read) Warning: Permanently added '10.128.0.60' (ECDSA) to the list of known hosts. [ 23.267070] random: sshd: uninitialized urandom read (32 bytes read) 2018/05/06 09:25:24 parsed 1 programs 2018/05/06 09:25:24 executed programs: 0 [ 23.734627] IPVS: Creating netns size=2536 id=1 [ 23.746337] IPVS: Creating netns size=2536 id=2 [ 23.779325] IPVS: Creating netns size=2536 id=3 [ 23.795226] IPVS: Creating netns size=2536 id=4 [ 23.826398] IPVS: Creating netns size=2536 id=5 [ 23.844703] ================================================================== [ 23.852088] BUG: KASAN: slab-out-of-bounds in tun_net_xmit+0x10bd/0x1180 [ 23.858896] Read of size 8 at addr ffff8801cb159b78 by task swapper/1/0 [ 23.865613] [ 23.867214] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.98-g63a812b #20 [ 23.874107] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 23.883431] ffff8801db3073e8 ffffffff81eb0e89 ffffea00072c5640 ffff8801cb159b78 [ 23.891401] 0000000000000000 ffff8801cb159b78 ffff8801d97ab848 ffff8801db307420 [ 23.899374] ffffffff815652cb ffff8801cb159b78 0000000000000008 0000000000000000 [ 23.907346] Call Trace: [ 23.909898] [ 23.911932] [] dump_stack+0xc1/0x128 [ 23.917291] [] print_address_description+0x6c/0x234 [ 23.923923] [] kasan_report.cold.6+0x242/0x2fe [ 23.930140] [] ? tun_net_xmit+0x10bd/0x1180 [ 23.936083] [] __asan_report_load8_noabort+0x14/0x20 [ 23.942803] [] tun_net_xmit+0x10bd/0x1180 [ 23.948571] [] ? tun_net_xmit+0x4d/0x1180 [ 23.954352] [] dev_hard_start_xmit+0x197/0x8b0 [ 23.960553] [] sch_direct_xmit+0x2bc/0x590 [ 23.966406] [] ? dev_watchdog+0x7a0/0x7a0 [ 23.972171] [] ? dev_queue_xmit+0x17/0x20 [ 23.977939] [] __dev_queue_xmit+0x1742/0x2080 [ 23.984051] [] ? dev_queue_xmit+0x17/0x20 [ 23.989817] [] ? netdev_pick_tx+0x2c0/0x2c0 [ 23.995762] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 24.002051] [] ? check_preemption_disabled+0x3b/0x170 [ 24.008861] [] ? check_preemption_disabled+0x3b/0x170 [ 24.015671] [] dev_queue_xmit+0x17/0x20 [ 24.021266] [] neigh_direct_output+0x15/0x20 [ 24.027296] [] ip6_finish_output2+0x8a8/0x1d00 [ 24.033493] [] ? ip6_finish_output2+0x157/0x1d00 [ 24.039877] [] ? ip6_sk_dst_lookup_flow+0x580/0x580 [ 24.046513] [] ? check_preemption_disabled+0x3b/0x170 [ 24.053323] [] ? ip6_mtu+0x217/0x340 [ 24.058657] [] ip6_finish_output+0x3b8/0x760 [ 24.064692] [] ip6_output+0x1f3/0x6e0 [ 24.070114] [] ? ip6_output+0x2f0/0x6e0 [ 24.075707] [] ? ip6_finish_output+0x760/0x760 [ 24.081915] [] ? nf_hook_slow+0xda/0x1e0 [ 24.087598] [] ? ip6_fragment+0x3380/0x3380 [ 24.093546] [] ? check_preemption_disabled+0x3b/0x170 [ 24.100357] [] ? NF_HOOK_THRESH.constprop.41+0x13d/0x450 [ 24.107425] [] NF_HOOK_THRESH.constprop.41+0x286/0x450 [ 24.114320] [] ? igmp6_mcf_seq_start+0x550/0x550 [ 24.120695] [] ? igmp6_mcf_seq_start+0x550/0x550 [ 24.127073] [] ? trace_hardirqs_on_caller+0x18a/0x590 [ 24.133887] [] ? mld_dad_start_timer+0x90/0x90 [ 24.140094] [] ? icmp6_dst_alloc+0x403/0x610 [ 24.146122] [] mld_sendpack+0x649/0xbd0 [ 24.151715] [] ? mld_sendpack+0x173/0xbd0 [ 24.157482] [] ? NF_HOOK_THRESH.constprop.41+0x450/0x450 [ 24.164555] [] ? mark_held_locks+0xc7/0x130 [ 24.170502] [] ? mld_ifc_timer_expire+0x3a4/0x740 [ 24.176965] [] ? trace_hardirqs_on+0xd/0x10 [ 24.182906] [] mld_ifc_timer_expire+0x3ba/0x740 [ 24.189196] [] call_timer_fn+0x163/0x6e0 [ 24.194877] [] ? call_timer_fn+0xda/0x6e0 [ 24.200646] [] ? debug_object_deactivate+0x214/0x340 [ 24.207376] [] ? mld_dad_timer_expire+0xf0/0xf0 [ 24.213664] [] ? process_timeout+0x20/0x20 [ 24.219519] [] ? _raw_spin_unlock_irq+0x27/0x50 [ 24.225808] [] ? mld_dad_timer_expire+0xf0/0xf0 [ 24.232099] [] ? trace_hardirqs_on_caller+0x266/0x590 [ 24.239083] [] ? mld_dad_timer_expire+0xf0/0xf0 [ 24.245371] [] run_timer_softirq+0x1047/0x1590 [ 24.251572] [] ? clockevents_tick_resume+0x60/0x60 [ 24.258130] [] ? add_timer+0xca0/0xca0 [ 24.263642] [] ? check_preemption_disabled+0x3b/0x170 [ 24.270450] [] __do_softirq+0x20b/0x937 [ 24.276049] [] irq_exit+0x147/0x190 [ 24.281295] [] smp_apic_timer_interrupt+0x81/0xa0 [ 24.287756] [] apic_timer_interrupt+0xa0/0xb0 [ 24.293873] [ 24.295915] [] ? native_safe_halt+0x6/0x10 [ 24.301788] [] ? trace_hardirqs_on+0xd/0x10 [ 24.307729] [] default_idle+0x55/0x360 [ 24.313238] [] arch_cpu_idle+0x10/0x20 [ 24.318746] [] default_idle_call+0x45/0x60 [ 24.324600] [] cpu_startup_entry+0x2b5/0x380 [ 24.330624] [] ? cpu_in_idle+0x20/0x20 [ 24.336132] [] start_secondary+0x323/0x400 [ 24.341987] [] ? set_cpu_sibling_map+0x1300/0x1300 [ 24.348534] [ 24.350133] Allocated by task 3845: [ 24.353728] save_stack_trace+0x16/0x20 [ 24.357670] save_stack+0x43/0xd0 [ 24.361092] kasan_kmalloc+0xc7/0xe0 [ 24.364781] __kmalloc+0x11d/0x300 [ 24.368291] tun_device_event+0x3e3/0xa10 [ 24.372408] notifier_call_chain+0xb4/0x1d0 [ 24.376697] raw_notifier_call_chain+0x2d/0x40 [ 24.381253] call_netdevice_notifiers_info+0x55/0x70 [ 24.386328] call_netdevice_notifiers+0x70/0xa0 [ 24.390968] do_setlink+0xc3b/0x30d0 [ 24.394653] rtnl_newlink+0xbd0/0x1550 [ 24.398507] rtnetlink_rcv_msg+0x49c/0x650 [ 24.402710] netlink_rcv_skb+0x145/0x370 [ 24.406740] rtnetlink_rcv+0x2a/0x40 [ 24.410423] netlink_unicast+0x4d8/0x6f0 [ 24.414455] netlink_sendmsg+0x78b/0xc10 [ 24.418485] sock_sendmsg+0xcc/0x110 [ 24.422167] ___sys_sendmsg+0x6fc/0x840 [ 24.426111] __sys_sendmsg+0xd9/0x190 [ 24.429880] SyS_sendmsg+0x2d/0x50 [ 24.433390] do_syscall_64+0x1a6/0x490 [ 24.437248] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.442317] [ 24.443912] Freed by task 2070: [ 24.447161] save_stack_trace+0x16/0x20 [ 24.451104] save_stack+0x43/0xd0 [ 24.454529] kasan_slab_free+0x72/0xc0 [ 24.458392] kfree+0xfb/0x310 [ 24.461475] kernfs_fop_write+0x181/0x460 [ 24.465592] __vfs_write+0x115/0x580 [ 24.469275] vfs_write+0x187/0x530 [ 24.472790] SyS_write+0xd9/0x1c0 [ 24.476218] do_syscall_64+0x1a6/0x490 [ 24.480076] entry_SYSCALL_64_after_swapgs+0x5d/0xdb [ 24.485147] [ 24.486744] The buggy address belongs to the object at ffff8801cb159b70 [ 24.486744] which belongs to the cache kmalloc-8 of size 8 [ 24.499020] The buggy address is located 0 bytes to the right of [ 24.499020] 8-byte region [ffff8801cb159b70, ffff8801cb159b78) [ 24.511753] The buggy address belongs to the page: [ 24.516664] page:ffffea00072c5640 count:1 mapcount:0 mapping: (null) index:0x0 [ 24.524890] flags: 0x8000000000000080(slab) [ 24.529179] page dumped because: kasan: bad access detected [ 24.534854] [ 24.536451] Memory state around the buggy address: [ 24.541347] ffff8801cb159a00: fc 00 fc fc 00 fc fc 00 fc fc 00 fc fc 00 fc fc [ 24.548675] ffff8801cb159a80: 00 fc fc 00 fc fc 00 fc fc fb fc fc fb fc fc 00 [ 24.556004] >ffff8801cb159b00: fc fc 00 fc fc 00 fc fc 00 fc fc 00 fc fc 00 fc [ 24.563328] ^ [ 24.570568] ffff8801cb159b80: fc fb fc fc fb fc fc 00 fc fc 00 fc fc 00 fc fc [ 24.577895] ffff8801cb159c00: 00 fc fc 00 fc fc 00 fc fc 00 fc fc 04 fc fc fb [ 24.585220] ================================================================== [ 24.592546] Disabling lock debugging due to kernel taint [ 24.598008] Kernel panic - not syncing: panic_on_warn set ... [ 24.598008] [ 24.605352] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G B 4.9.98-g63a812b #20 [ 24.613461] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 24.622791] ffff8801db307348 ffffffff81eb0e89 ffffffff843c4fe5 00000000ffffffff [ 24.630794] 0000000000000000 0000000000000001 ffff8801d97ab848 ffff8801db307408 [ 24.638776] ffffffff8141f835 0000000041b58ab3 ffffffff843b86e8 ffffffff8141f676 [ 24.646755] Call Trace: [ 24.649308] [ 24.651364] [] dump_stack+0xc1/0x128 [ 24.656718] [] panic+0x1bf/0x3bc [ 24.661707] [] ? add_taint.cold.6+0x16/0x16 [ 24.667659] [] kasan_end_report+0x47/0x4f [ 24.673431] [] kasan_report.cold.6+0x76/0x2fe [ 24.679549] [] ? tun_net_xmit+0x10bd/0x1180 [ 24.685491] [] __asan_report_load8_noabort+0x14/0x20 [ 24.692218] [] tun_net_xmit+0x10bd/0x1180 [ 24.697990] [] ? tun_net_xmit+0x4d/0x1180 [ 24.703766] [] dev_hard_start_xmit+0x197/0x8b0 [ 24.709973] [] sch_direct_xmit+0x2bc/0x590 [ 24.715836] [] ? dev_watchdog+0x7a0/0x7a0 [ 24.721604] [] ? dev_queue_xmit+0x17/0x20 [ 24.727371] [] __dev_queue_xmit+0x1742/0x2080 [ 24.733487] [] ? dev_queue_xmit+0x17/0x20 [ 24.739254] [] ? netdev_pick_tx+0x2c0/0x2c0 [ 24.745201] [] ? __local_bh_enable_ip+0x6a/0xd0 [ 24.751493] [] ? check_preemption_disabled+0x3b/0x170 [ 24.758305] [] ? check_preemption_disabled+0x3b/0x170 [ 24.765121] [] dev_queue_xmit+0x17/0x20 [ 24.770716] [] neigh_direct_output+0x15/0x20 [ 24.776747] [] ip6_finish_output2+0x8a8/0x1d00 [ 24.782950] [] ? ip6_finish_output2+0x157/0x1d00 [ 24.789326] [] ? ip6_sk_dst_lookup_flow+0x580/0x580 [ 24.795964] [] ? check_preemption_disabled+0x3b/0x170 [ 24.802780] [] ? ip6_mtu+0x217/0x340 [ 24.808116] [] ip6_finish_output+0x3b8/0x760 [ 24.814144] [] ip6_output+0x1f3/0x6e0 [ 24.819564] [] ? ip6_output+0x2f0/0x6e0 [ 24.825157] [] ? ip6_finish_output+0x760/0x760 [ 24.831358] [] ? nf_hook_slow+0xda/0x1e0 [ 24.837037] [] ? ip6_fragment+0x3380/0x3380 [ 24.842986] [] ? check_preemption_disabled+0x3b/0x170 [ 24.849803] [] ? NF_HOOK_THRESH.constprop.41+0x13d/0x450 [ 24.856872] [] NF_HOOK_THRESH.constprop.41+0x286/0x450 [ 24.863777] [] ? igmp6_mcf_seq_start+0x550/0x550 [ 24.870152] [] ? igmp6_mcf_seq_start+0x550/0x550 [ 24.876530] [] ? trace_hardirqs_on_caller+0x18a/0x590 [ 24.883337] [] ? mld_dad_start_timer+0x90/0x90 [ 24.889542] [] ? icmp6_dst_alloc+0x403/0x610 [ 24.895570] [] mld_sendpack+0x649/0xbd0 [ 24.901164] [] ? mld_sendpack+0x173/0xbd0 [ 24.906934] [] ? NF_HOOK_THRESH.constprop.41+0x450/0x450 [ 24.914003] [] ? mark_held_locks+0xc7/0x130 [ 24.919946] [] ? mld_ifc_timer_expire+0x3a4/0x740 [ 24.926409] [] ? trace_hardirqs_on+0xd/0x10 [ 24.932347] [] mld_ifc_timer_expire+0x3ba/0x740 [ 24.938637] [] call_timer_fn+0x163/0x6e0 [ 24.944318] [] ? call_timer_fn+0xda/0x6e0 [ 24.950086] [] ? debug_object_deactivate+0x214/0x340 [ 24.956807] [] ? mld_dad_timer_expire+0xf0/0xf0 [ 24.963095] [] ? process_timeout+0x20/0x20 [ 24.968957] [] ? _raw_spin_unlock_irq+0x27/0x50 [ 24.975244] [] ? mld_dad_timer_expire+0xf0/0xf0 [ 24.981535] [] ? trace_hardirqs_on_caller+0x266/0x590 [ 24.988346] [] ? mld_dad_timer_expire+0xf0/0xf0 [ 24.994634] [] run_timer_softirq+0x1047/0x1590 [ 25.000835] [] ? clockevents_tick_resume+0x60/0x60 [ 25.007383] [] ? add_timer+0xca0/0xca0 [ 25.012893] [] ? check_preemption_disabled+0x3b/0x170 [ 25.019703] [] __do_softirq+0x20b/0x937 [ 25.025299] [] irq_exit+0x147/0x190 [ 25.030555] [] smp_apic_timer_interrupt+0x81/0xa0 [ 25.037018] [] apic_timer_interrupt+0xa0/0xb0 [ 25.043128] [ 25.045166] [] ? native_safe_halt+0x6/0x10 [ 25.051307] [] ? trace_hardirqs_on+0xd/0x10 [ 25.057249] [] default_idle+0x55/0x360 [ 25.062762] [] arch_cpu_idle+0x10/0x20 [ 25.068271] [] default_idle_call+0x45/0x60 [ 25.074123] [] cpu_startup_entry+0x2b5/0x380 [ 25.080154] [] ? cpu_in_idle+0x20/0x20 [ 25.085662] [] start_secondary+0x323/0x400 [ 25.091517] [] ? set_cpu_sibling_map+0x1300/0x1300 [ 25.098513] Dumping ftrace buffer: [ 25.102040] (ftrace buffer empty) [ 25.105720] Kernel Offset: disabled [ 25.109324] Rebooting in 86400 seconds..