[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.506503][ T25] audit: type=1800 audit(1571725066.877:25): pid=7090 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.534568][ T25] audit: type=1800 audit(1571725066.877:26): pid=7090 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.567426][ T25] audit: type=1800 audit(1571725066.887:27): pid=7090 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 '10.128.10.36' (ECDSA) to the list of known hosts. 2019/10/22 06:17:57 fuzzer started 2019/10/22 06:17:59 dialing manager at 10.128.0.105:37053 2019/10/22 06:17:59 syscalls: 2524 2019/10/22 06:17:59 code coverage: enabled 2019/10/22 06:17:59 comparison tracing: enabled 2019/10/22 06:17:59 extra coverage: extra coverage is not supported by the kernel 2019/10/22 06:17:59 setuid sandbox: enabled 2019/10/22 06:17:59 namespace sandbox: enabled 2019/10/22 06:17:59 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 06:17:59 fault injection: enabled 2019/10/22 06:17:59 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 06:17:59 net packet injection: enabled 2019/10/22 06:17:59 net device setup: enabled 2019/10/22 06:17:59 concurrency sanitizer: enabled syzkaller login: [ 49.780959][ T7253] ================================================================== [ 49.789114][ T7253] BUG: KCSAN: data-race in __nf_ct_refresh_acct / __nf_ct_refresh_acct [ 49.798113][ T7253] [ 49.800540][ T7253] read to 0xffff888122e34508 of 4 bytes by interrupt on cpu 0: [ 49.808350][ T7253] __nf_ct_refresh_acct+0xd4/0x1b0 [ 49.813517][ T7253] nf_conntrack_tcp_packet+0xd40/0x3390 [ 49.819279][ T7253] nf_conntrack_in+0x410/0xa80 [ 49.824559][ T7253] ipv4_conntrack_in+0x27/0x40 [ 49.829337][ T7253] nf_hook_slow+0x83/0x160 [ 49.833902][ T7253] ip_rcv+0x12f/0x1a0 [ 49.837887][ T7253] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.843582][ T7253] __netif_receive_skb+0x37/0xf0 [ 49.848500][ T7253] netif_receive_skb_internal+0x59/0x190 [ 49.854120][ T7253] napi_gro_receive+0x28f/0x330 [ 49.858961][ T7253] receive_buf+0x284/0x30b0 [ 49.863725][ T7253] virtnet_poll+0x436/0x7d0 [ 49.868243][ T7253] net_rx_action+0x3ae/0xa90 [ 49.872831][ T7253] __do_softirq+0x115/0x33f [ 49.877311][ T7253] [ 49.879628][ T7253] write to 0xffff888122e34508 of 4 bytes by task 7253 on cpu 1: [ 49.887733][ T7253] __nf_ct_refresh_acct+0xfb/0x1b0 [ 49.893929][ T7253] nf_conntrack_tcp_packet+0xd40/0x3390 [ 49.899574][ T7253] nf_conntrack_in+0x410/0xa80 [ 49.904580][ T7253] ipv4_conntrack_local+0xbe/0x130 [ 49.909680][ T7253] nf_hook_slow+0x83/0x160 [ 49.914272][ T7253] __ip_local_out+0x1f7/0x2b0 [ 49.919027][ T7253] ip_local_out+0x31/0x90 [ 49.923336][ T7253] __ip_queue_xmit+0x3a8/0xa40 [ 49.928100][ T7253] ip_queue_xmit+0x45/0x60 [ 49.933080][ T7253] __tcp_transmit_skb+0xe81/0x1d60 [ 49.938191][ T7253] __tcp_send_ack+0x246/0x300 [ 49.942851][ T7253] tcp_send_ack+0x34/0x40 [ 49.947171][ T7253] tcp_cleanup_rbuf+0x130/0x360 [ 49.951996][ T7253] [ 49.954300][ T7253] Reported by Kernel Concurrency Sanitizer on: [ 49.960438][ T7253] CPU: 1 PID: 7253 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.967971][ T7253] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.978001][ T7253] ================================================================== [ 49.986038][ T7253] Kernel panic - not syncing: panic_on_warn set ... [ 49.992616][ T7253] CPU: 1 PID: 7253 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.000052][ T7253] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.010170][ T7253] Call Trace: [ 50.013481][ T7253] dump_stack+0xf5/0x159 [ 50.017726][ T7253] panic+0x210/0x640 [ 50.022075][ T7253] ? ip_queue_xmit+0x45/0x60 [ 50.026652][ T7253] ? vprintk_func+0x8d/0x140 [ 50.031339][ T7253] kcsan_report.cold+0xc/0x10 [ 50.036022][ T7253] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 50.041568][ T7253] __tsan_write4+0x32/0x40 [ 50.046063][ T7253] __nf_ct_refresh_acct+0xfb/0x1b0 [ 50.051169][ T7253] nf_conntrack_tcp_packet+0xd40/0x3390 [ 50.056706][ T7253] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 50.062338][ T7253] nf_conntrack_in+0x410/0xa80 [ 50.067085][ T7253] ipv4_conntrack_local+0xbe/0x130 [ 50.072191][ T7253] nf_hook_slow+0x83/0x160 [ 50.076605][ T7253] ? nf_ct_tcp_fixup+0xe0/0xe0 [ 50.082476][ T7253] __ip_local_out+0x1f7/0x2b0 [ 50.087231][ T7253] ? constant_test_bit+0x30/0x30 [ 50.092299][ T7253] ip_local_out+0x31/0x90 [ 50.096724][ T7253] __ip_queue_xmit+0x3a8/0xa40 [ 50.101475][ T7253] ip_queue_xmit+0x45/0x60 [ 50.106101][ T7253] __tcp_transmit_skb+0xe81/0x1d60 [ 50.111328][ T7253] __tcp_send_ack+0x246/0x300 [ 50.116008][ T7253] tcp_send_ack+0x34/0x40 [ 50.120328][ T7253] tcp_cleanup_rbuf+0x130/0x360 [ 50.125174][ T7253] tcp_recvmsg+0x633/0x1a30 [ 50.129675][ T7253] inet_recvmsg+0xbb/0x250 [ 50.134085][ T7253] ? __tsan_read8+0x2c/0x30 [ 50.138637][ T7253] ? inet_sendpage+0x100/0x100 [ 50.143687][ T7253] sock_recvmsg+0x92/0xb0 [ 50.148035][ T7253] sock_read_iter+0x15f/0x1e0 [ 50.152712][ T7253] new_sync_read+0x389/0x4f0 [ 50.157548][ T7253] __vfs_read+0xb1/0xc0 [ 50.161684][ T7253] vfs_read+0x143/0x2c0 [ 50.165834][ T7253] ksys_read+0xd5/0x1b0 [ 50.170077][ T7253] __x64_sys_read+0x4c/0x60 [ 50.174579][ T7253] do_syscall_64+0xcc/0x370 [ 50.179064][ T7253] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.185141][ T7253] RIP: 0033:0x47c530 [ 50.189027][ T7253] 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 [ 50.208614][ T7253] RSP: 002b:000000c420051810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 50.217180][ T7253] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 50.225216][ T7253] RDX: 0000000000001000 RSI: 000000c42015e000 RDI: 0000000000000003 [ 50.233164][ T7253] RBP: 000000c420051868 R08: 0000000000000000 R09: 0000000000000000 [ 50.241218][ T7253] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000100 [ 50.249182][ T7253] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 50.259399][ T7253] Kernel Offset: disabled [ 50.264236][ T7253] Rebooting in 86400 seconds..