[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.472489][ T26] audit: type=1800 audit(1572047114.921:25): pid=6972 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 33.499407][ T26] audit: type=1800 audit(1572047114.921:26): pid=6972 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 33.537220][ T26] audit: type=1800 audit(1572047114.921:27): pid=6972 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 '10.128.1.31' (ECDSA) to the list of known hosts. 2019/10/25 23:45:22 fuzzer started 2019/10/25 23:45:23 dialing manager at 10.128.0.105:32811 2019/10/25 23:45:23 syscalls: 2533 2019/10/25 23:45:23 code coverage: enabled 2019/10/25 23:45:23 comparison tracing: enabled 2019/10/25 23:45:23 extra coverage: extra coverage is not supported by the kernel 2019/10/25 23:45:23 setuid sandbox: enabled 2019/10/25 23:45:23 namespace sandbox: enabled 2019/10/25 23:45:23 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/25 23:45:23 fault injection: enabled 2019/10/25 23:45:23 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/25 23:45:23 net packet injection: enabled 2019/10/25 23:45:23 net device setup: enabled 2019/10/25 23:45:23 concurrency sanitizer: enabled 2019/10/25 23:45:27 adding functions to KCSAN blacklist: 'tomoyo_supervisor' 'echo_char' 'blk_mq_sched_dispatch_requests' 'schedule_hrtimeout_range_clock' '__hrtimer_run_queues' 'ktime_get_real_seconds' 'ext4_free_inode' 'blk_mq_get_request' 'run_timer_softirq' 'pid_update_inode' 'common_perm_cond' 'tcp_add_backlog' 'mod_timer' '__tcp_select_window' 'generic_permission' 'tick_do_update_jiffies64' syzkaller login: [ 46.996083][ T7144] ================================================================== [ 47.004217][ T7144] BUG: KCSAN: data-race in __nf_ct_refresh_acct / __nf_ct_refresh_acct [ 47.012441][ T7144] [ 47.014767][ T7144] read to 0xffff888125c26608 of 4 bytes by interrupt on cpu 1: [ 47.022299][ T7144] __nf_ct_refresh_acct+0xd4/0x1b0 [ 47.027387][ T7144] nf_conntrack_tcp_packet+0xd40/0x3390 [ 47.032907][ T7144] nf_conntrack_in+0x410/0xa80 [ 47.037643][ T7144] ipv4_conntrack_in+0x27/0x40 [ 47.042385][ T7144] nf_hook_slow+0x83/0x160 [ 47.046774][ T7144] ip_rcv+0x12f/0x1a0 [ 47.050743][ T7144] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.056435][ T7144] __netif_receive_skb+0x37/0xf0 [ 47.061359][ T7144] netif_receive_skb_internal+0x59/0x190 [ 47.066971][ T7144] napi_gro_receive+0x28f/0x330 [ 47.071797][ T7144] receive_buf+0x284/0x30b0 [ 47.076273][ T7144] virtnet_poll+0x436/0x7d0 [ 47.080748][ T7144] net_rx_action+0x3ae/0xa90 [ 47.085317][ T7144] __do_softirq+0x115/0x33f [ 47.089800][ T7144] [ 47.092105][ T7144] write to 0xffff888125c26608 of 4 bytes by task 7144 on cpu 0: [ 47.099742][ T7144] __nf_ct_refresh_acct+0xfb/0x1b0 [ 47.104838][ T7144] nf_conntrack_tcp_packet+0xd40/0x3390 [ 47.110357][ T7144] nf_conntrack_in+0x410/0xa80 [ 47.115130][ T7144] ipv4_conntrack_local+0xbe/0x130 [ 47.120217][ T7144] nf_hook_slow+0x83/0x160 [ 47.124627][ T7144] __ip_local_out+0x1f7/0x2b0 [ 47.129278][ T7144] ip_local_out+0x31/0x90 [ 47.133601][ T7144] __ip_queue_xmit+0x3a8/0xa40 [ 47.138339][ T7144] ip_queue_xmit+0x45/0x60 [ 47.142726][ T7144] __tcp_transmit_skb+0xe81/0x1d60 [ 47.147810][ T7144] __tcp_send_ack+0x246/0x300 [ 47.152458][ T7144] tcp_send_ack+0x34/0x40 [ 47.156782][ T7144] tcp_cleanup_rbuf+0x130/0x360 [ 47.161599][ T7144] [ 47.163898][ T7144] Reported by Kernel Concurrency Sanitizer on: [ 47.170026][ T7144] CPU: 0 PID: 7144 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.177450][ T7144] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.187479][ T7144] ================================================================== [ 47.195510][ T7144] Kernel panic - not syncing: panic_on_warn set ... [ 47.202069][ T7144] CPU: 0 PID: 7144 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.209494][ T7144] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.219517][ T7144] Call Trace: [ 47.222784][ T7144] dump_stack+0xf5/0x159 [ 47.227011][ T7144] panic+0x210/0x640 [ 47.230881][ T7144] ? ip_queue_xmit+0x45/0x60 [ 47.235446][ T7144] ? vprintk_func+0x8d/0x140 [ 47.240023][ T7144] kcsan_report.cold+0xc/0x10 [ 47.244676][ T7144] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.250198][ T7144] __tsan_write4+0x32/0x40 [ 47.254590][ T7144] __nf_ct_refresh_acct+0xfb/0x1b0 [ 47.259675][ T7144] nf_conntrack_tcp_packet+0xd40/0x3390 [ 47.265202][ T7144] ? ieee80211_csa_finalize+0x6d/0x630 [ 47.270637][ T7144] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.276249][ T7144] nf_conntrack_in+0x410/0xa80 [ 47.280990][ T7144] ipv4_conntrack_local+0xbe/0x130 [ 47.286074][ T7144] nf_hook_slow+0x83/0x160 [ 47.290462][ T7144] ? nf_ct_tcp_fixup+0xe0/0xe0 [ 47.295205][ T7144] __ip_local_out+0x1f7/0x2b0 [ 47.299863][ T7144] ? constant_test_bit+0x30/0x30 [ 47.304775][ T7144] ip_local_out+0x31/0x90 [ 47.309077][ T7144] __ip_queue_xmit+0x3a8/0xa40 [ 47.313834][ T7144] ip_queue_xmit+0x45/0x60 [ 47.318230][ T7144] __tcp_transmit_skb+0xe81/0x1d60 [ 47.323327][ T7144] __tcp_send_ack+0x246/0x300 [ 47.328021][ T7144] tcp_send_ack+0x34/0x40 [ 47.332328][ T7144] tcp_cleanup_rbuf+0x130/0x360 [ 47.337160][ T7144] tcp_recvmsg+0x633/0x1a30 [ 47.341650][ T7144] inet_recvmsg+0xbb/0x250 [ 47.346077][ T7144] ? __tsan_read8+0x2c/0x30 [ 47.350558][ T7144] ? inet_sendpage+0x100/0x100 [ 47.355297][ T7144] sock_recvmsg+0x92/0xb0 [ 47.359603][ T7144] sock_read_iter+0x15f/0x1e0 [ 47.364302][ T7144] new_sync_read+0x389/0x4f0 [ 47.368870][ T7144] __vfs_read+0xb1/0xc0 [ 47.373021][ T7144] vfs_read+0x143/0x2c0 [ 47.377159][ T7144] ksys_read+0xd5/0x1b0 [ 47.381290][ T7144] __x64_sys_read+0x4c/0x60 [ 47.385768][ T7144] do_syscall_64+0xcc/0x370 [ 47.390249][ T7144] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.396124][ T7144] RIP: 0033:0x47c530 [ 47.400000][ T7144] 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 [ 47.419577][ T7144] RSP: 002b:000000c42036d7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.427960][ T7144] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.435905][ T7144] RDX: 0000000000001000 RSI: 000000c4202f0000 RDI: 0000000000000003 [ 47.443850][ T7144] RBP: 000000c42036d830 R08: 0000000000000000 R09: 0000000000000000 [ 47.451793][ T7144] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000040 [ 47.459738][ T7144] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 47.468895][ T7144] Kernel Offset: disabled [ 47.473209][ T7144] Rebooting in 86400 seconds..