[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.212194][ T25] audit: type=1800 audit(1571765408.345:25): pid=7043 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.231991][ T25] audit: type=1800 audit(1571765408.345:26): pid=7043 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.253593][ T25] audit: type=1800 audit(1571765408.345:27): pid=7043 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 periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.184' (ECDSA) to the list of known hosts. 2019/10/22 17:30:16 fuzzer started 2019/10/22 17:30:18 dialing manager at 10.128.0.105:33369 2019/10/22 17:30:18 syscalls: 2524 2019/10/22 17:30:18 code coverage: enabled 2019/10/22 17:30:18 comparison tracing: enabled 2019/10/22 17:30:18 extra coverage: extra coverage is not supported by the kernel 2019/10/22 17:30:18 setuid sandbox: enabled 2019/10/22 17:30:18 namespace sandbox: enabled 2019/10/22 17:30:18 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 17:30:18 fault injection: enabled 2019/10/22 17:30:18 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 17:30:18 net packet injection: enabled 2019/10/22 17:30:18 net device setup: enabled 2019/10/22 17:30:18 concurrency sanitizer: enabled syzkaller login: [ 45.011179][ T10] ================================================================== [ 45.019429][ T10] BUG: KCSAN: data-race in rcu_gp_fqs_check_wake / rcu_note_context_switch [ 45.028004][ T10] [ 45.030343][ T10] write to 0xffffffff85a7d490 of 8 bytes by task 7210 on cpu 0: [ 45.037985][ T10] rcu_note_context_switch+0x6f6/0x760 [ 45.043483][ T10] __schedule+0xa4/0x640 [ 45.047736][ T10] preempt_schedule_irq+0x57/0x90 [ 45.052763][ T10] restore_regs_and_return_to_kernel+0x0/0x25 [ 45.058840][ T10] __sanitizer_cov_trace_const_cmp1+0x1/0x20 [ 45.064826][ T10] nf_conntrack_in+0x410/0xa80 [ 45.069591][ T10] ipv4_conntrack_local+0xbe/0x130 [ 45.075144][ T10] nf_hook_slow+0x83/0x160 [ 45.079560][ T10] __ip_local_out+0x1f7/0x2b0 [ 45.084239][ T10] ip_local_out+0x31/0x90 [ 45.088564][ T10] __ip_queue_xmit+0x3a8/0xa40 [ 45.093329][ T10] ip_queue_xmit+0x45/0x60 [ 45.097922][ T10] __tcp_transmit_skb+0xe81/0x1d60 [ 45.103029][ T10] __tcp_send_ack+0x246/0x300 [ 45.107691][ T10] [ 45.110019][ T10] read to 0xffffffff85a7d490 of 8 bytes by task 10 on cpu 1: [ 45.117377][ T10] rcu_gp_fqs_check_wake+0x93/0xd0 [ 45.122469][ T10] rcu_gp_fqs_loop+0x36c/0x580 [ 45.127210][ T10] rcu_gp_kthread+0x143/0x230 [ 45.131866][ T10] kthread+0x1d4/0x200 [ 45.135914][ T10] ret_from_fork+0x1f/0x30 [ 45.140322][ T10] [ 45.142652][ T10] Reported by Kernel Concurrency Sanitizer on: [ 45.148819][ T10] CPU: 1 PID: 10 Comm: rcu_preempt Not tainted 5.4.0-rc3+ #0 [ 45.156159][ T10] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.166189][ T10] ================================================================== [ 45.174239][ T10] Kernel panic - not syncing: panic_on_warn set ... [ 45.180820][ T10] CPU: 1 PID: 10 Comm: rcu_preempt Not tainted 5.4.0-rc3+ #0 [ 45.188171][ T10] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 45.198198][ T10] Call Trace: [ 45.201470][ T10] dump_stack+0xf5/0x159 [ 45.205691][ T10] panic+0x210/0x640 [ 45.209566][ T10] ? vprintk_func+0x8d/0x140 [ 45.214135][ T10] kcsan_report.cold+0xc/0x10 [ 45.218790][ T10] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 45.224329][ T10] __tsan_read8+0x2c/0x30 [ 45.228638][ T10] rcu_gp_fqs_check_wake+0x93/0xd0 [ 45.233742][ T10] rcu_gp_fqs_loop+0x36c/0x580 [ 45.238489][ T10] rcu_gp_kthread+0x143/0x230 [ 45.243146][ T10] kthread+0x1d4/0x200 [ 45.247191][ T10] ? rcu_gp_cleanup+0x520/0x520 [ 45.252017][ T10] ? kthread_stop+0x2d0/0x2d0 [ 45.256672][ T10] ret_from_fork+0x1f/0x30 [ 45.262411][ T10] Kernel Offset: disabled [ 45.266732][ T10] Rebooting in 86400 seconds..