[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.553572][ T25] audit: type=1800 audit(1572278878.307:25): pid=7096 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.580846][ T25] audit: type=1800 audit(1572278878.307:26): pid=7096 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.626081][ T25] audit: type=1800 audit(1572278878.307:27): pid=7096 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 '10.128.1.48' (ECDSA) to the list of known hosts. 2019/10/28 16:08:09 fuzzer started 2019/10/28 16:08:10 dialing manager at 10.128.0.105:45117 2019/10/28 16:08:10 syscalls: 2540 2019/10/28 16:08:10 code coverage: enabled 2019/10/28 16:08:10 comparison tracing: enabled 2019/10/28 16:08:10 extra coverage: extra coverage is not supported by the kernel 2019/10/28 16:08:10 setuid sandbox: enabled 2019/10/28 16:08:10 namespace sandbox: enabled 2019/10/28 16:08:10 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/28 16:08:10 fault injection: enabled 2019/10/28 16:08:10 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/28 16:08:10 net packet injection: enabled 2019/10/28 16:08:10 net device setup: enabled 2019/10/28 16:08:10 concurrency sanitizer: enabled 2019/10/28 16:08:11 adding functions to KCSAN blacklist: 'rcu_gp_fqs_loop' '__tcp_select_window' '__hrtimer_run_queues' 'pid_update_inode' 'tick_sched_do_timer' syzkaller login: [ 50.319198][ C1] ================================================================== [ 50.328133][ C1] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 50.336098][ C1] [ 50.338430][ C1] read to 0xffff88812524b2f8 of 8 bytes by task 7250 on cpu 0: [ 50.346632][ C1] tcp_recvmsg+0x470/0x1a30 [ 50.351277][ C1] inet_recvmsg+0xbb/0x250 [ 50.355894][ C1] sock_recvmsg+0x92/0xb0 [ 50.360314][ C1] sock_read_iter+0x15f/0x1e0 [ 50.364984][ C1] new_sync_read+0x389/0x4f0 [ 50.369662][ C1] __vfs_read+0xb1/0xc0 [ 50.373809][ C1] vfs_read+0x143/0x2c0 [ 50.377954][ C1] ksys_read+0xd5/0x1b0 [ 50.382373][ C1] __x64_sys_read+0x4c/0x60 [ 50.387133][ C1] do_syscall_64+0xcc/0x370 [ 50.391744][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.397622][ C1] [ 50.399946][ C1] write to 0xffff88812524b2f8 of 8 bytes by interrupt on cpu 1: [ 50.407671][ C1] tcp_add_backlog+0x45a/0xcc0 [ 50.412473][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 50.417033][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 50.422405][ C1] ip_local_deliver_finish+0x110/0x140 [ 50.427928][ C1] ip_local_deliver+0x133/0x210 [ 50.432862][ C1] ip_rcv_finish+0x121/0x160 [ 50.438037][ C1] ip_rcv+0x18f/0x1a0 [ 50.442031][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.448062][ C1] __netif_receive_skb+0x37/0xf0 [ 50.453097][ C1] netif_receive_skb_internal+0x59/0x190 [ 50.458768][ C1] napi_gro_receive+0x28f/0x330 [ 50.463902][ C1] receive_buf+0x284/0x30b0 [ 50.468500][ C1] virtnet_poll+0x436/0x7d0 [ 50.473078][ C1] [ 50.475484][ C1] Reported by Kernel Concurrency Sanitizer on: [ 50.481633][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 50.489080][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.499329][ C1] ================================================================== [ 50.507649][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 50.514329][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 50.523503][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.533803][ C1] Call Trace: [ 50.537116][ C1] dump_stack+0xf5/0x159 [ 50.541470][ C1] panic+0x210/0x640 [ 50.545544][ C1] ? __netif_receive_skb+0x37/0xf0 [ 50.550736][ C1] ? vprintk_func+0x8d/0x140 [ 50.555424][ C1] kcsan_report.cold+0xc/0x10 [ 50.560203][ C1] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 50.565940][ C1] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 50.571875][ C1] __tsan_write8+0x32/0x40 [ 50.576294][ C1] tcp_add_backlog+0x45a/0xcc0 [ 50.581074][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 50.585602][ C1] ? __tsan_read8+0x2c/0x30 [ 50.591502][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 50.597570][ C1] ip_local_deliver_finish+0x110/0x140 [ 50.603803][ C1] ip_local_deliver+0x133/0x210 [ 50.608753][ C1] ? ip_protocol_deliver_rcu+0x420/0x420 [ 50.614479][ C1] ip_rcv_finish+0x121/0x160 [ 50.619253][ C1] ip_rcv+0x18f/0x1a0 [ 50.623234][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 50.628078][ C1] ? ip_local_deliver+0x210/0x210 [ 50.633185][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 50.639231][ C1] __netif_receive_skb+0x37/0xf0 [ 50.644165][ C1] netif_receive_skb_internal+0x59/0x190 [ 50.649937][ C1] napi_gro_receive+0x28f/0x330 [ 50.654788][ C1] receive_buf+0x284/0x30b0 [ 50.659285][ C1] ? __tsan_write8+0x32/0x40 [ 50.663876][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 50.669331][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 50.675289][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 50.680916][ C1] virtnet_poll+0x436/0x7d0 [ 50.685419][ C1] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 50.691664][ C1] net_rx_action+0x3ae/0xa90 [ 50.696530][ C1] __do_softirq+0x115/0x33f [ 50.701029][ C1] ? takeover_tasklets+0x250/0x250 [ 50.706136][ C1] run_ksoftirqd+0x46/0x60 [ 50.710554][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 50.718010][ C1] kthread+0x1d4/0x200 [ 50.722089][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 50.728147][ C1] ? kthread_stop+0x2d0/0x2d0 [ 50.732907][ C1] ret_from_fork+0x1f/0x30 [ 50.739862][ C1] Kernel Offset: disabled [ 50.744439][ C1] Rebooting in 86400 seconds..