[....] 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. [ 29.553077] kauditd_printk_skb: 7 callbacks suppressed [ 29.553088] audit: type=1800 audit(1545006591.959:29): pid=5889 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 [ 29.587851] audit: type=1800 audit(1545006591.959:30): pid=5889 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 Warning: Permanently added '10.128.0.75' (ECDSA) to the list of known hosts. syzkaller login: [ 36.976579] IPVS: ftp: loaded support on port[0] = 21 net.ipv6.conf.syz_tun.accept_dad = 0 net.ipv6.conf.syz_tun.router_solicitations = 0 [ 37.230722] bridge0: port 1(bridge_slave_0) entered blocking state [ 37.237753] bridge0: port 1(bridge_slave_0) entered disabled state [ 37.245529] device bridge_slave_0 entered promiscuous mode [ 37.264071] bridge0: port 2(bridge_slave_1) entered blocking state [ 37.270498] bridge0: port 2(bridge_slave_1) entered disabled state [ 37.277710] device bridge_slave_1 entered promiscuous mode [ 37.297797] IPv6: ADDRCONF(NETDEV_UP): veth0_to_bridge: link is not ready [ 37.315704] IPv6: ADDRCONF(NETDEV_UP): veth1_to_bridge: link is not ready [ 37.365857] bond0: Enslaving bond_slave_0 as an active interface with an up link [ 37.385883] bond0: Enslaving bond_slave_1 as an active interface with an up link [ 37.463543] IPv6: ADDRCONF(NETDEV_UP): team_slave_0: link is not ready [ 37.470892] team0: Port device team_slave_0 added [ 37.488136] IPv6: ADDRCONF(NETDEV_UP): team_slave_1: link is not ready [ 37.495392] team0: Port device team_slave_1 added [ 37.512760] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready [ 37.532805] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready [ 37.553291] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_bridge: link becomes ready [ 37.573408] 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 [ 37.720680] bridge0: port 2(bridge_slave_1) entered blocking state [ 37.727158] bridge0: port 2(bridge_slave_1) entered forwarding state [ 37.734187] bridge0: port 1(bridge_slave_0) entered blocking state [ 37.740526] 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 [ 38.277934] 8021q: adding VLAN 0 to HW filter on device bond0 [ 38.329766] IPv6: ADDRCONF(NETDEV_UP): veth0: link is not ready [ 38.381584] IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready [ 38.387769] IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready [ 38.395749] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready [ 38.449978] 8021q: adding VLAN 0 to HW filter on device team0 executing program [ 38.742446] ================================================================== [ 38.749900] BUG: KASAN: use-after-free in tick_sched_handle+0x16c/0x180 [ 38.756636] Read of size 8 at addr ffff8881d2a27c60 by task syz-executor238/6044 [ 38.764146] [ 38.765764] CPU: 1 PID: 6044 Comm: syz-executor238 Not tainted 4.20.0-rc6+ #348 [ 38.773191] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 38.782528] Call Trace: [ 38.785110] [ 38.787255] dump_stack+0x244/0x39d [ 38.790868] ? dump_stack_print_info.cold.1+0x20/0x20 [ 38.796058] ? printk+0xa7/0xcf [ 38.799339] ? kmsg_dump_rewind_nolock+0xe4/0xe4 [ 38.804085] print_address_description.cold.7+0x9/0x1ff [ 38.809435] kasan_report.cold.8+0x242/0x309 [ 38.813831] ? tick_sched_handle+0x16c/0x180 [ 38.818231] __asan_report_load8_noabort+0x14/0x20 [ 38.823146] tick_sched_handle+0x16c/0x180 [ 38.827369] tick_sched_timer+0x45/0x130 [ 38.831431] __hrtimer_run_queues+0x41c/0x10d0 [ 38.836039] ? tick_sched_do_timer+0x1a0/0x1a0 [ 38.840612] ? hrtimer_start_range_ns+0xe00/0xe00 [ 38.845444] ? pvclock_read_flags+0x160/0x160 [ 38.849925] ? trace_hardirqs_on+0x310/0x310 [ 38.854321] ? kvm_clock_read+0x18/0x30 [ 38.858283] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 38.863285] ? ktime_get_update_offsets_now+0x3b3/0x540 [ 38.868638] ? do_timer+0x50/0x50 [ 38.872076] ? rwlock_bug.part.2+0x90/0x90 [ 38.876296] ? trace_hardirqs_on+0x310/0x310 [ 38.880691] ? rcu_softirq_qs+0x20/0x20 [ 38.884673] hrtimer_interrupt+0x313/0x780 [ 38.888906] smp_apic_timer_interrupt+0x1a1/0x760 [ 38.893732] ? smp_reschedule_interrupt+0x109/0x650 [ 38.898735] ? smp_call_function_single_interrupt+0x650/0x650 [ 38.904606] ? interrupt_entry+0xb5/0xc0 [ 38.908653] ? trace_hardirqs_off_caller+0xbb/0x310 [ 38.913672] ? trace_hardirqs_off_caller+0xbb/0x310 [ 38.918682] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 38.923512] ? trace_hardirqs_on_caller+0x310/0x310 [ 38.928510] ? trace_hardirqs_on_caller+0x310/0x310 [ 38.933513] ? task_prio+0x50/0x50 [ 38.937044] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 38.942568] ? check_preemption_disabled+0x48/0x280 [ 38.947591] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 38.952433] apic_timer_interrupt+0xf/0x20 [ 38.956650] [ 38.958867] [ 38.960473] The buggy address belongs to the page: [ 38.965386] page:ffffea00074a89c0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 [ 38.973509] flags: 0x2fffc0000000000() [ 38.977385] raw: 02fffc0000000000 0000000000000000 ffffffff074a0101 0000000000000000 [ 38.985249] raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 [ 38.993107] page dumped because: kasan: bad access detected [ 38.998797] [ 39.000402] Memory state around the buggy address: [ 39.005313] ffff8881d2a27b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 39.012658] ffff8881d2a27b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 39.019999] >ffff8881d2a27c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 39.027343] ^ [ 39.033818] ffff8881d2a27c80: ff ff ff ff ff ff ff ff ff ff ff ff ff f1 f1 f1 [ 39.041180] ffff8881d2a27d00: f1 00 f2 f2 f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 f2 [ 39.048533] ================================================================== [ 39.055874] Disabling lock debugging due to kernel taint [ 39.061317] Kernel panic - not syncing: panic_on_warn set ... [ 39.067191] CPU: 1 PID: 6044 Comm: syz-executor238 Tainted: G B 4.20.0-rc6+ #348 [ 39.076356] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 39.085708] Call Trace: [ 39.088276] [ 39.090418] dump_stack+0x244/0x39d [ 39.094029] ? dump_stack_print_info.cold.1+0x20/0x20 [ 39.099221] panic+0x2ad/0x55c [ 39.102404] ? add_taint.cold.5+0x16/0x16 [ 39.106543] ? add_taint.cold.5+0x5/0x16 [ 39.110599] ? trace_hardirqs_off+0xaf/0x310 [ 39.114994] kasan_end_report+0x47/0x4f [ 39.118954] kasan_report.cold.8+0x76/0x309 [ 39.123282] ? tick_sched_handle+0x16c/0x180 [ 39.127679] __asan_report_load8_noabort+0x14/0x20 [ 39.132599] tick_sched_handle+0x16c/0x180 [ 39.136833] tick_sched_timer+0x45/0x130 [ 39.140895] __hrtimer_run_queues+0x41c/0x10d0 [ 39.145465] ? tick_sched_do_timer+0x1a0/0x1a0 [ 39.150031] ? hrtimer_start_range_ns+0xe00/0xe00 [ 39.154863] ? pvclock_read_flags+0x160/0x160 [ 39.159344] ? trace_hardirqs_on+0x310/0x310 [ 39.163740] ? kvm_clock_read+0x18/0x30 [ 39.167697] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 39.172713] ? ktime_get_update_offsets_now+0x3b3/0x540 [ 39.178084] ? do_timer+0x50/0x50 [ 39.181521] ? rwlock_bug.part.2+0x90/0x90 [ 39.185741] ? trace_hardirqs_on+0x310/0x310 [ 39.190131] ? rcu_softirq_qs+0x20/0x20 [ 39.194091] hrtimer_interrupt+0x313/0x780 [ 39.198330] smp_apic_timer_interrupt+0x1a1/0x760 [ 39.203203] ? smp_reschedule_interrupt+0x109/0x650 [ 39.208203] ? smp_call_function_single_interrupt+0x650/0x650 [ 39.214072] ? interrupt_entry+0xb5/0xc0 [ 39.218119] ? trace_hardirqs_off_caller+0xbb/0x310 [ 39.223120] ? trace_hardirqs_off_caller+0xbb/0x310 [ 39.228119] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.232944] ? trace_hardirqs_on_caller+0x310/0x310 [ 39.237941] ? trace_hardirqs_on_caller+0x310/0x310 [ 39.242939] ? task_prio+0x50/0x50 [ 39.246480] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 39.252000] ? check_preemption_disabled+0x48/0x280 [ 39.257002] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 39.261849] apic_timer_interrupt+0xf/0x20 [ 39.266061] [ 39.269364] Kernel Offset: disabled [ 39.272990] Rebooting in 86400 seconds..