[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.119423][ T25] audit: type=1800 audit(1571794692.091:25): pid=7093 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 39.139376][ T25] audit: type=1800 audit(1571794692.091:26): pid=7093 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 39.159421][ T25] audit: type=1800 audit(1571794692.101:27): pid=7093 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 '10.128.0.221' (ECDSA) to the list of known hosts. 2019/10/23 01:38:23 fuzzer started 2019/10/23 01:38:24 dialing manager at 10.128.0.105:33369 2019/10/23 01:38:24 syscalls: 2524 2019/10/23 01:38:24 code coverage: enabled 2019/10/23 01:38:24 comparison tracing: enabled 2019/10/23 01:38:24 extra coverage: extra coverage is not supported by the kernel 2019/10/23 01:38:24 setuid sandbox: enabled 2019/10/23 01:38:24 namespace sandbox: enabled 2019/10/23 01:38:24 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/23 01:38:24 fault injection: enabled 2019/10/23 01:38:24 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/23 01:38:24 net packet injection: enabled 2019/10/23 01:38:24 net device setup: enabled 2019/10/23 01:38:24 concurrency sanitizer: enabled syzkaller login: [ 52.230667][ T7246] ================================================================== [ 52.238986][ T7246] BUG: KCSAN: data-race in __nf_ct_refresh_acct / __nf_ct_refresh_acct [ 52.247199][ T7246] [ 52.249508][ T7246] read to 0xffff888120d1a608 of 4 bytes by interrupt on cpu 1: [ 52.257031][ T7246] __nf_ct_refresh_acct+0xd4/0x1b0 [ 52.262123][ T7246] nf_conntrack_tcp_packet+0xd40/0x3390 [ 52.267646][ T7246] nf_conntrack_in+0x410/0xa80 [ 52.272387][ T7246] ipv4_conntrack_in+0x27/0x40 [ 52.277825][ T7246] nf_hook_slow+0x83/0x160 [ 52.282233][ T7246] ip_rcv+0x12f/0x1a0 [ 52.286197][ T7246] __netif_receive_skb_one_core+0xa7/0xe0 [ 52.291954][ T7246] __netif_receive_skb+0x37/0xf0 [ 52.296891][ T7246] netif_receive_skb_internal+0x59/0x190 [ 52.302520][ T7246] napi_gro_receive+0x28f/0x330 [ 52.307441][ T7246] receive_buf+0x284/0x30b0 [ 52.311922][ T7246] virtnet_poll+0x436/0x7d0 [ 52.316403][ T7246] net_rx_action+0x3ae/0xa90 [ 52.320972][ T7246] __do_softirq+0x115/0x33f [ 52.325444][ T7246] [ 52.327757][ T7246] write to 0xffff888120d1a608 of 4 bytes by task 7246 on cpu 0: [ 52.335450][ T7246] __nf_ct_refresh_acct+0xfb/0x1b0 [ 52.340537][ T7246] nf_conntrack_tcp_packet+0xd40/0x3390 [ 52.346057][ T7246] nf_conntrack_in+0x410/0xa80 [ 52.351495][ T7246] ipv4_conntrack_local+0xbe/0x130 [ 52.356583][ T7246] nf_hook_slow+0x83/0x160 [ 52.360978][ T7246] __ip_local_out+0x1f7/0x2b0 [ 52.365631][ T7246] ip_local_out+0x31/0x90 [ 52.369951][ T7246] __ip_queue_xmit+0x3a8/0xa40 [ 52.374690][ T7246] ip_queue_xmit+0x45/0x60 [ 52.379098][ T7246] __tcp_transmit_skb+0xe81/0x1d60 [ 52.384191][ T7246] __tcp_send_ack+0x246/0x300 [ 52.388868][ T7246] tcp_send_ack+0x34/0x40 [ 52.393174][ T7246] tcp_cleanup_rbuf+0x130/0x360 [ 52.398008][ T7246] [ 52.400327][ T7246] Reported by Kernel Concurrency Sanitizer on: [ 52.406471][ T7246] CPU: 0 PID: 7246 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.413898][ T7246] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.423932][ T7246] ================================================================== [ 52.431967][ T7246] Kernel panic - not syncing: panic_on_warn set ... [ 52.438532][ T7246] CPU: 0 PID: 7246 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.446080][ T7246] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.456221][ T7246] Call Trace: [ 52.459771][ T7246] dump_stack+0xf5/0x159 [ 52.463997][ T7246] panic+0x210/0x640 [ 52.467879][ T7246] ? ip_queue_xmit+0x45/0x60 [ 52.472469][ T7246] ? vprintk_func+0x8d/0x140 [ 52.477049][ T7246] kcsan_report.cold+0xc/0x10 [ 52.481903][ T7246] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 52.487449][ T7246] __tsan_write4+0x32/0x40 [ 52.491856][ T7246] __nf_ct_refresh_acct+0xfb/0x1b0 [ 52.497044][ T7246] nf_conntrack_tcp_packet+0xd40/0x3390 [ 52.502577][ T7246] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 52.508190][ T7246] nf_conntrack_in+0x410/0xa80 [ 52.512936][ T7246] ipv4_conntrack_local+0xbe/0x130 [ 52.518031][ T7246] nf_hook_slow+0x83/0x160 [ 52.522433][ T7246] ? nf_ct_tcp_fixup+0xe0/0xe0 [ 52.527177][ T7246] __ip_local_out+0x1f7/0x2b0 [ 52.531865][ T7246] ? constant_test_bit+0x30/0x30 [ 52.536794][ T7246] ip_local_out+0x31/0x90 [ 52.541107][ T7246] __ip_queue_xmit+0x3a8/0xa40 [ 52.545872][ T7246] ip_queue_xmit+0x45/0x60 [ 52.550273][ T7246] __tcp_transmit_skb+0xe81/0x1d60 [ 52.555399][ T7246] __tcp_send_ack+0x246/0x300 [ 52.560060][ T7246] tcp_send_ack+0x34/0x40 [ 52.564379][ T7246] tcp_cleanup_rbuf+0x130/0x360 [ 52.569211][ T7246] tcp_recvmsg+0x633/0x1a30 [ 52.573710][ T7246] inet_recvmsg+0xbb/0x250 [ 52.578110][ T7246] ? __tsan_read8+0x2c/0x30 [ 52.582592][ T7246] ? inet_sendpage+0x100/0x100 [ 52.587334][ T7246] sock_recvmsg+0x92/0xb0 [ 52.591658][ T7246] sock_read_iter+0x15f/0x1e0 [ 52.596318][ T7246] new_sync_read+0x389/0x4f0 [ 52.600894][ T7246] __vfs_read+0xb1/0xc0 [ 52.605029][ T7246] vfs_read+0x143/0x2c0 [ 52.609302][ T7246] ksys_read+0xd5/0x1b0 [ 52.613456][ T7246] __x64_sys_read+0x4c/0x60 [ 52.617951][ T7246] do_syscall_64+0xcc/0x370 [ 52.622436][ T7246] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.628307][ T7246] RIP: 0033:0x47c530 [ 52.632188][ T7246] 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 [ 52.651777][ T7246] RSP: 002b:000000c420315810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 52.660168][ T7246] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 52.668115][ T7246] RDX: 0000000000001000 RSI: 000000c4202ba000 RDI: 0000000000000003 [ 52.676072][ T7246] RBP: 000000c420315868 R08: 0000000000000000 R09: 0000000000000000 [ 52.684033][ T7246] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 [ 52.691982][ T7246] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 52.701412][ T7246] Kernel Offset: disabled [ 52.705734][ T7246] Rebooting in 86400 seconds..