[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.448129][ T25] audit: type=1800 audit(1571115093.042:25): pid=6951 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [ 34.624485][ T25] audit: type=1800 audit(1571115093.222:26): pid=6951 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.660225][ T25] audit: type=1800 audit(1571115093.262:27): pid=6951 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2469 res=0 [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.63' (ECDSA) to the list of known hosts. 2019/10/15 04:51:40 fuzzer started syzkaller login: [ 42.668568][ T7109] as (7109) used greatest stack depth: 10032 bytes left 2019/10/15 04:51:41 dialing manager at 10.128.0.105:33683 2019/10/15 04:51:41 syscalls: 2523 2019/10/15 04:51:41 code coverage: enabled 2019/10/15 04:51:41 comparison tracing: enabled 2019/10/15 04:51:41 extra coverage: extra coverage is not supported by the kernel 2019/10/15 04:51:41 setuid sandbox: enabled 2019/10/15 04:51:41 namespace sandbox: enabled 2019/10/15 04:51:41 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/15 04:51:41 fault injection: enabled 2019/10/15 04:51:41 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/15 04:51:41 net packet injection: enabled 2019/10/15 04:51:41 net device setup: enabled 2019/10/15 04:51:41 concurrency sanitizer: enabled [ 43.129454][ C0] ================================================================== [ 43.137700][ C0] BUG: KCSAN: data-race in tick_sched_do_timer / tick_sched_do_timer [ 43.145859][ C0] [ 43.148183][ C0] write to 0xffffffff85caf310 of 4 bytes by interrupt on cpu 1: [ 43.155798][ C0] tick_sched_do_timer+0xc0/0xe0 [ 43.160730][ C0] tick_sched_timer+0x43/0xe0 [ 43.165388][ C0] __hrtimer_run_queues+0x288/0x600 [ 43.170779][ C0] hrtimer_interrupt+0x22a/0x480 [ 43.175692][ C0] smp_apic_timer_interrupt+0xdc/0x280 [ 43.181124][ C0] apic_timer_interrupt+0xf/0x20 [ 43.186055][ C0] nf_conntrack_tcp_packet+0x1c07/0x3390 [ 43.191668][ C0] nf_conntrack_in+0x410/0xaa0 [ 43.196419][ C0] ipv4_conntrack_in+0x27/0x40 [ 43.201176][ C0] nf_hook_slow+0x83/0x160 [ 43.205683][ C0] ip_rcv+0x12f/0x1a0 [ 43.209649][ C0] __netif_receive_skb_one_core+0xa7/0xe0 [ 43.215349][ C0] __netif_receive_skb+0x37/0xf0 [ 43.220269][ C0] netif_receive_skb_internal+0x59/0x190 [ 43.225886][ C0] [ 43.228197][ C0] read to 0xffffffff85caf310 of 4 bytes by interrupt on cpu 0: [ 43.235723][ C0] tick_sched_do_timer+0x33/0xe0 [ 43.240651][ C0] tick_sched_timer+0x43/0xe0 [ 43.245315][ C0] __hrtimer_run_queues+0x288/0x600 [ 43.250489][ C0] hrtimer_interrupt+0x22a/0x480 [ 43.255403][ C0] smp_apic_timer_interrupt+0xdc/0x280 [ 43.260842][ C0] apic_timer_interrupt+0xf/0x20 [ 43.265771][ C0] __kcsan_check_watchpoint+0x7c/0x180 [ 43.271215][ C0] __tsan_read4+0x15/0x30 [ 43.275522][ C0] start_xmit+0x111/0xc20 [ 43.279830][ C0] dev_hard_start_xmit+0xef/0x430 [ 43.284855][ C0] sch_direct_xmit+0x2b3/0x870 [ 43.289599][ C0] __dev_queue_xmit+0x172e/0x1b90 [ 43.294612][ C0] dev_queue_xmit+0x21/0x30 [ 43.299084][ C0] [ 43.301386][ C0] Reported by Kernel Concurrency Sanitizer on: [ 43.307515][ C0] CPU: 0 PID: 7105 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 43.314608][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.324738][ C0] ================================================================== [ 43.332785][ C0] Kernel panic - not syncing: panic_on_warn set ... [ 43.339348][ C0] CPU: 0 PID: 7105 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 43.346433][ C0] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 43.356464][ C0] Call Trace: [ 43.359740][ C0] [ 43.362600][ C0] dump_stack+0xf5/0x159 [ 43.366849][ C0] panic+0x209/0x639 [ 43.370726][ C0] ? start_xmit+0x111/0xc20 [ 43.375219][ C0] ? vprintk_func+0x8d/0x140 [ 43.379810][ C0] kcsan_report.cold+0xc/0x1b [ 43.384485][ C0] __kcsan_setup_watchpoint+0x3ee/0x510 [ 43.390020][ C0] __tsan_read4+0x2c/0x30 [ 43.394328][ C0] tick_sched_do_timer+0x33/0xe0 [ 43.399264][ C0] tick_sched_timer+0x43/0xe0 [ 43.403924][ C0] __hrtimer_run_queues+0x288/0x600 [ 43.409100][ C0] ? tick_sched_do_timer+0xe0/0xe0 [ 43.414421][ C0] hrtimer_interrupt+0x22a/0x480 [ 43.419406][ C0] smp_apic_timer_interrupt+0xdc/0x280 [ 43.424909][ C0] apic_timer_interrupt+0xf/0x20 [ 43.429837][ C0] [ 43.432768][ C0] RIP: 0010:__kcsan_check_watchpoint+0x7c/0x180 [ 43.438998][ C0] Code: 89 ee 4c 89 ef 44 0f b6 e2 48 b9 ff ff ff ff ff ff 00 00 48 c1 ee 0c 31 d2 48 21 cf 83 e6 3f 41 ba ab aa aa aa 4e 8d 4c 37 ff <8d> 42 01 48 89 c2 49 0f af c2 89 d3 48 c1 e8 21 8d 04 40 29 c3 8d [ 43.458608][ C0] RSP: 0018:ffffc900018f7418 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13 [ 43.467173][ C0] RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000ffffffffffff [ 43.476079][ C0] RDX: 0000000000000001 RSI: 0000000000000022 RDI: 0000888124de27bc [ 43.484064][ C0] RBP: ffffc900018f7440 R08: 0000000000000000 R09: 0000888124de27bf [ 43.492124][ C0] R10: 00000000aaaaaaab R11: ffffffff86042d30 R12: 0000000000000000 [ 43.500373][ C0] R13: ffff888124de27bc R14: 0000000000000004 R15: ffff88812ac53000 [ 43.508341][ C0] ? tap_ioctl+0x41/0xa70 [ 43.512654][ C0] __tsan_read4+0x15/0x30 [ 43.516967][ C0] start_xmit+0x111/0xc20 [ 43.521294][ C0] dev_hard_start_xmit+0xef/0x430 [ 43.526304][ C0] sch_direct_xmit+0x2b3/0x870 [ 43.531046][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 43.536659][ C0] __dev_queue_xmit+0x172e/0x1b90 [ 43.541662][ C0] ? ipt_do_table+0x8e6/0xe40 [ 43.546314][ C0] ? __tsan_read1+0x2c/0x30 [ 43.550807][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 43.556416][ C0] ? __tsan_write4+0x32/0x40 [ 43.560990][ C0] dev_queue_xmit+0x21/0x30 [ 43.565492][ C0] ip_finish_output2+0x834/0xe40 [ 43.570433][ C0] __ip_finish_output+0x23a/0x490 [ 43.575456][ C0] ip_finish_output+0x41/0x160 [ 43.580200][ C0] ip_output+0xdf/0x210 [ 43.584351][ C0] ? __ip_finish_output+0x490/0x490 [ 43.589551][ C0] ip_local_out+0x74/0x90 [ 43.593876][ C0] __ip_queue_xmit+0x3a8/0xa40 [ 43.598852][ C0] ip_queue_xmit+0x45/0x60 [ 43.603261][ C0] __tcp_transmit_skb+0xdeb/0x1cd0 [ 43.608365][ C0] __tcp_send_ack+0x246/0x300 [ 43.613027][ C0] tcp_send_ack+0x34/0x40 [ 43.617338][ C0] tcp_cleanup_rbuf+0x130/0x360 [ 43.622169][ C0] tcp_recvmsg+0x633/0x1a30 [ 43.626697][ C0] ? __kcsan_setup_watchpoint+0x96/0x510 [ 43.632312][ C0] inet_recvmsg+0xbb/0x250 [ 43.636704][ C0] ? __tsan_read8+0x2c/0x30 [ 43.641187][ C0] ? inet_sendpage+0x100/0x100 [ 43.645928][ C0] sock_recvmsg+0x92/0xb0 [ 43.650247][ C0] sock_read_iter+0x15f/0x1e0 [ 43.654959][ C0] new_sync_read+0x389/0x4f0 [ 43.659557][ C0] __vfs_read+0xb1/0xc0 [ 43.663731][ C0] vfs_read+0x143/0x2c0 [ 43.667889][ C0] ksys_read+0xd5/0x1b0 [ 43.672029][ C0] __x64_sys_read+0x4c/0x60 [ 43.676686][ C0] do_syscall_64+0xcf/0x2f0 [ 43.681172][ C0] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 43.687054][ C0] RIP: 0033:0x47c530 [ 43.690958][ C0] Code: 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 49 c7 c2 00 00 00 00 49 c7 c0 00 00 00 00 49 c7 c1 00 00 00 00 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 43.713615][ C0] RSP: 002b:000000c4203097d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 43.722004][ C0] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 43.729951][ C0] RDX: 0000000000001000 RSI: 000000c4203d0000 RDI: 0000000000000003 [ 43.737903][ C0] RBP: 000000c420309830 R08: 0000000000000000 R09: 0000000000000000 [ 43.745880][ C0] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 43.753837][ C0] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 43.763384][ C0] Kernel Offset: disabled [ 43.767723][ C0] Rebooting in 86400 seconds..