[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.714058][ T26] audit: type=1800 audit(1571788227.815:25): pid=7069 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.733912][ T26] audit: type=1800 audit(1571788227.815:26): pid=7069 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.759854][ T26] audit: type=1800 audit(1571788227.815:27): pid=7069 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 '10.128.0.109' (ECDSA) to the list of known hosts. 2019/10/22 23:50:39 fuzzer started 2019/10/22 23:50:40 dialing manager at 10.128.0.105:33369 2019/10/22 23:50:40 syscalls: 2524 2019/10/22 23:50:40 code coverage: enabled 2019/10/22 23:50:40 comparison tracing: enabled 2019/10/22 23:50:40 extra coverage: extra coverage is not supported by the kernel 2019/10/22 23:50:40 setuid sandbox: enabled 2019/10/22 23:50:40 namespace sandbox: enabled 2019/10/22 23:50:40 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 23:50:40 fault injection: enabled 2019/10/22 23:50:40 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 23:50:40 net packet injection: enabled 2019/10/22 23:50:40 net device setup: enabled 2019/10/22 23:50:40 concurrency sanitizer: enabled syzkaller login: [ 46.468495][ C1] ================================================================== [ 46.476609][ C1] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 46.483606][ C1] [ 46.485921][ C1] read to 0xffff88812a2b32f8 of 8 bytes by task 7220 on cpu 0: [ 46.493880][ C1] tcp_recvmsg+0x470/0x1a30 [ 46.498391][ C1] inet_recvmsg+0xbb/0x250 [ 46.502817][ C1] sock_recvmsg+0x92/0xb0 [ 46.507143][ C1] sock_read_iter+0x15f/0x1e0 [ 46.511803][ C1] new_sync_read+0x389/0x4f0 [ 46.516374][ C1] __vfs_read+0xb1/0xc0 [ 46.520513][ C1] vfs_read+0x143/0x2c0 [ 46.524668][ C1] ksys_read+0xd5/0x1b0 [ 46.528895][ C1] __x64_sys_read+0x4c/0x60 [ 46.533383][ C1] do_syscall_64+0xcc/0x370 [ 46.537892][ C1] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 46.543759][ C1] [ 46.546073][ C1] write to 0xffff88812a2b32f8 of 8 bytes by interrupt on cpu 1: [ 46.553687][ C1] tcp_add_backlog+0x45a/0xcc0 [ 46.558446][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 46.562934][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 46.568288][ C1] ip_local_deliver_finish+0x110/0x140 [ 46.573728][ C1] ip_local_deliver+0x133/0x210 [ 46.578560][ C1] ip_rcv_finish+0x121/0x160 [ 46.583130][ C1] ip_rcv+0x18f/0x1a0 [ 46.587109][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 46.592811][ C1] __netif_receive_skb+0x37/0xf0 [ 46.597731][ C1] netif_receive_skb_internal+0x59/0x190 [ 46.603348][ C1] napi_gro_receive+0x28f/0x330 [ 46.608180][ C1] receive_buf+0x284/0x30b0 [ 46.612672][ C1] virtnet_poll+0x436/0x7d0 [ 46.617147][ C1] [ 46.619455][ C1] Reported by Kernel Concurrency Sanitizer on: [ 46.625593][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 46.632937][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.642972][ C1] ================================================================== [ 46.651014][ C1] Kernel panic - not syncing: panic_on_warn set ... [ 46.657587][ C1] CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0 [ 46.664932][ C1] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 46.674964][ C1] Call Trace: [ 46.678247][ C1] dump_stack+0xf5/0x159 [ 46.682474][ C1] panic+0x210/0x640 [ 46.686353][ C1] ? __netif_receive_skb+0x37/0xf0 [ 46.691449][ C1] ? vprintk_func+0x8d/0x140 [ 46.696037][ C1] kcsan_report.cold+0xc/0x10 [ 46.700960][ C1] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 46.706489][ C1] ? __sanitizer_cov_trace_cmp4+0x16/0x20 [ 46.712199][ C1] __tsan_write8+0x32/0x40 [ 46.716614][ C1] tcp_add_backlog+0x45a/0xcc0 [ 46.721370][ C1] tcp_v4_rcv+0x1a60/0x1bb0 [ 46.725856][ C1] ? __tsan_read8+0x2c/0x30 [ 46.730349][ C1] ip_protocol_deliver_rcu+0x4d/0x420 [ 46.735706][ C1] ip_local_deliver_finish+0x110/0x140 [ 46.741152][ C1] ip_local_deliver+0x133/0x210 [ 46.745991][ C1] ? ip_protocol_deliver_rcu+0x420/0x420 [ 46.751611][ C1] ip_rcv_finish+0x121/0x160 [ 46.756185][ C1] ip_rcv+0x18f/0x1a0 [ 46.760158][ C1] ? ip_sublist_rcv+0x5e0/0x5e0 [ 46.764992][ C1] ? ip_local_deliver+0x210/0x210 [ 46.769999][ C1] __netif_receive_skb_one_core+0xa7/0xe0 [ 46.775714][ C1] __netif_receive_skb+0x37/0xf0 [ 46.780640][ C1] netif_receive_skb_internal+0x59/0x190 [ 46.786272][ C1] napi_gro_receive+0x28f/0x330 [ 46.791112][ C1] receive_buf+0x284/0x30b0 [ 46.795599][ C1] ? __tsan_write8+0x32/0x40 [ 46.800184][ C1] ? virtqueue_get_buf_ctx+0x4fd/0x5c0 [ 46.805627][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 46.811241][ C1] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 46.816871][ C1] virtnet_poll+0x436/0x7d0 [ 46.821367][ C1] net_rx_action+0x3ae/0xa90 [ 46.825949][ C1] __do_softirq+0x115/0x33f [ 46.830443][ C1] ? takeover_tasklets+0x250/0x250 [ 46.835537][ C1] run_ksoftirqd+0x46/0x60 [ 46.840026][ C1] smpboot_thread_fn+0x37d/0x4a0 [ 46.844950][ C1] kthread+0x1d4/0x200 [ 46.849005][ C1] ? constant_test_bit.constprop.0+0x30/0x30 [ 46.854968][ C1] ? kthread_stop+0x2d0/0x2d0 [ 46.859631][ C1] ret_from_fork+0x1f/0x30 [ 46.865172][ C1] Kernel Offset: disabled [ 46.869532][ C1] Rebooting in 86400 seconds..