[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 29.085014] kauditd_printk_skb: 8 callbacks suppressed [ 29.085026] audit: type=1800 audit(1545592761.932:29): pid=5881 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 29.116974] audit: type=1800 audit(1545592761.942:30): pid=5881 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 33.865149] sshd (6019) used greatest stack depth: 15728 bytes left Warning: Permanently added '10.128.0.42' (ECDSA) to the list of known hosts. net.ipv6.conf.syz_tun.accept_dad = 0 net.ipv6.conf.syz_tun.router_solicitations = 0 [ 40.551053] IPVS: ftp: loaded support on port[0] = 21 [ 40.813694] bridge0: port 1(bridge_slave_0) entered blocking state [ 40.820770] bridge0: port 1(bridge_slave_0) entered disabled state [ 40.828207] device bridge_slave_0 entered promiscuous mode [ 40.847056] bridge0: port 2(bridge_slave_1) entered blocking state [ 40.853499] bridge0: port 2(bridge_slave_1) entered disabled state [ 40.860643] device bridge_slave_1 entered promiscuous mode [ 40.878888] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 40.898113] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 40.948015] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 40.969571] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 41.050527] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 41.058132] team0: Port device team_slave_0 added [ 41.076754] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 41.085357] team0: Port device team_slave_1 added [ 41.103206] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 41.126222] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 41.146050] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 41.167897] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_bridge: link becomes ready RTNETLINK answers: Operation not supported RTNETLINK answers: No buffer space available RTNETLINK answers: Operation not supported [ 41.323691] bridge0: port 2(bridge_slave_1) entered blocking state [ 41.330187] bridge0: port 2(bridge_slave_1) entered forwarding state [ 41.337160] bridge0: port 1(bridge_slave_0) entered blocking state [ 41.343593] bridge0: port 1(bridge_slave_0) entered forwarding state RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Operation not supported RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument RTNETLINK answers: Invalid argument [ 41.890217] 8021q: adding VLAN 0 to HW filter on device bond0 [ 41.946775] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 41.999808] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 42.005931] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 42.013347] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 42.061309] 8021q: adding VLAN 0 to HW filter on device team0 [ 42.377547] ================================================================== [ 42.385034] BUG: KASAN: use-after-free in tick_sched_handle+0x16c/0x180 [ 42.391774] Read of size 8 at addr ffff8881c01850d0 by task syz-executor526/6036 [ 42.399353] [ 42.400978] CPU: 1 PID: 6036 Comm: syz-executor526 Not tainted 4.20.0-rc6-next-20181217+ #172 [ 42.409666] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.419013] Call Trace: [ 42.421605] [ 42.423876] dump_stack+0x244/0x39d [ 42.427512] ? dump_stack_print_info.cold.1+0x20/0x20 [ 42.432689] ? printk+0xa7/0xcf [ 42.435980] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 42.440737] ? kasan_check_read+0x11/0x20 [ 42.444883] print_address_description.cold.4+0x9/0x1ff [ 42.450243] ? tick_sched_handle+0x16c/0x180 [ 42.454744] kasan_report.cold.5+0x1b/0x39 [ 42.458964] ? tick_sched_handle+0x16c/0x180 [ 42.463356] ? tick_sched_handle+0x16c/0x180 [ 42.467749] __asan_report_load8_noabort+0x14/0x20 [ 42.472668] tick_sched_handle+0x16c/0x180 [ 42.476890] tick_sched_timer+0x45/0x130 [ 42.480944] __hrtimer_run_queues+0x41c/0x10d0 [ 42.485521] ? tick_sched_do_timer+0x1a0/0x1a0 [ 42.490091] ? hrtimer_start_range_ns+0xe00/0xe00 [ 42.494924] ? pvclock_read_flags+0x160/0x160 [ 42.499438] ? trace_hardirqs_on+0x310/0x310 [ 42.503838] ? kvm_clock_read+0x18/0x30 [ 42.507799] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 42.512800] ? ktime_get_update_offsets_now+0x3b3/0x540 [ 42.518154] ? do_timer+0x50/0x50 [ 42.521593] ? rwlock_bug.part.2+0x90/0x90 [ 42.525812] ? trace_hardirqs_on+0x310/0x310 [ 42.530234] ? rcu_softirq_qs+0x20/0x20 [ 42.534210] hrtimer_interrupt+0x313/0x780 [ 42.538444] smp_apic_timer_interrupt+0x1a1/0x760 [ 42.543300] ? smp_reschedule_interrupt+0x109/0x650 [ 42.548304] ? smp_call_function_single_interrupt+0x650/0x650 [ 42.554171] ? interrupt_entry+0xb5/0xc0 [ 42.558219] ? trace_hardirqs_off_caller+0xbb/0x310 [ 42.563218] ? trace_hardirqs_off_caller+0xbb/0x310 [ 42.568222] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.573054] ? trace_hardirqs_on_caller+0x310/0x310 [ 42.578056] ? trace_hardirqs_on_caller+0x310/0x310 [ 42.583071] ? task_prio+0x50/0x50 [ 42.586597] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 42.592121] ? check_preemption_disabled+0x48/0x280 [ 42.597169] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.602001] apic_timer_interrupt+0xf/0x20 [ 42.606216] [ 42.608440] [ 42.610051] The buggy address belongs to the page: [ 42.614961] page:ffffea0007006140 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 42.623084] flags: 0x2fffc0000000000() [ 42.626958] raw: 02fffc0000000000 0000000000000000 ffffffff07000101 0000000000000000 [ 42.634829] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 42.642690] page dumped because: kasan: bad access detected [ 42.648377] [ 42.650019] Memory state around the buggy address: [ 42.654942] ffff8881c0184f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 42.662281] ffff8881c0185000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 42.669622] >ffff8881c0185080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 42.676961] ^ [ 42.682943] ffff8881c0185100: ff ff ff ff ff ff ff ff ff ff ff ff f1 f1 f1 f1 [ 42.690311] ffff8881c0185180: 04 f2 f2 f2 ff ff 00 00 00 00 00 00 00 00 00 00 [ 42.697649] ================================================================== [ 42.704987] Disabling lock debugging due to kernel taint [ 42.710416] Kernel panic - not syncing: panic_on_warn set ... [ 42.716294] CPU: 1 PID: 6036 Comm: syz-executor526 Tainted: G B 4.20.0-rc6-next-20181217+ #172 [ 42.726334] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 42.735688] Call Trace: [ 42.738253] [ 42.740399] dump_stack+0x244/0x39d [ 42.744014] ? dump_stack_print_info.cold.1+0x20/0x20 [ 42.749208] ? tick_sched_handle+0xd0/0x180 [ 42.753515] panic+0x2ad/0x632 [ 42.756690] ? add_taint.cold.5+0x16/0x16 [ 42.760824] ? add_taint.cold.5+0x5/0x16 [ 42.764867] ? trace_hardirqs_off+0xaf/0x310 [ 42.769258] ? tick_sched_handle+0x16c/0x180 [ 42.773660] end_report+0x47/0x4f [ 42.777105] kasan_report.cold.5+0xe/0x39 [ 42.781236] ? tick_sched_handle+0x16c/0x180 [ 42.785625] ? tick_sched_handle+0x16c/0x180 [ 42.790019] __asan_report_load8_noabort+0x14/0x20 [ 42.794932] tick_sched_handle+0x16c/0x180 [ 42.799149] tick_sched_timer+0x45/0x130 [ 42.803196] __hrtimer_run_queues+0x41c/0x10d0 [ 42.807759] ? tick_sched_do_timer+0x1a0/0x1a0 [ 42.812325] ? hrtimer_start_range_ns+0xe00/0xe00 [ 42.817151] ? pvclock_read_flags+0x160/0x160 [ 42.821633] ? trace_hardirqs_on+0x310/0x310 [ 42.826029] ? kvm_clock_read+0x18/0x30 [ 42.829988] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 42.834990] ? ktime_get_update_offsets_now+0x3b3/0x540 [ 42.840337] ? do_timer+0x50/0x50 [ 42.843773] ? rwlock_bug.part.2+0x90/0x90 [ 42.847991] ? trace_hardirqs_on+0x310/0x310 [ 42.852380] ? rcu_softirq_qs+0x20/0x20 [ 42.856346] hrtimer_interrupt+0x313/0x780 [ 42.860571] smp_apic_timer_interrupt+0x1a1/0x760 [ 42.865404] ? smp_reschedule_interrupt+0x109/0x650 [ 42.870413] ? smp_call_function_single_interrupt+0x650/0x650 [ 42.876294] ? interrupt_entry+0xb5/0xc0 [ 42.880340] ? trace_hardirqs_off_caller+0xbb/0x310 [ 42.885338] ? trace_hardirqs_off_caller+0xbb/0x310 [ 42.890357] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.895223] ? trace_hardirqs_on_caller+0x310/0x310 [ 42.900223] ? trace_hardirqs_on_caller+0x310/0x310 [ 42.905225] ? task_prio+0x50/0x50 [ 42.908749] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 42.914285] ? check_preemption_disabled+0x48/0x280 [ 42.919298] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 42.924153] apic_timer_interrupt+0xf/0x20 [ 42.928366] [ 42.931546] Kernel Offset: disabled [ 42.935167] Rebooting in 86400 seconds..