[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.728819][ T25] audit: type=1800 audit(1572090120.517:25): pid=7018 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.748502][ T25] audit: type=1800 audit(1572090120.517:26): pid=7018 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.787565][ T25] audit: type=1800 audit(1572090120.517:27): pid=7018 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 '10.128.0.162' (ECDSA) to the list of known hosts. 2019/10/26 11:42:11 fuzzer started 2019/10/26 11:42:13 dialing manager at 10.128.0.105:33655 2019/10/26 11:42:13 syscalls: 2533 2019/10/26 11:42:13 code coverage: enabled 2019/10/26 11:42:13 comparison tracing: enabled 2019/10/26 11:42:13 extra coverage: extra coverage is not supported by the kernel 2019/10/26 11:42:13 setuid sandbox: enabled 2019/10/26 11:42:13 namespace sandbox: enabled 2019/10/26 11:42:13 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/26 11:42:13 fault injection: enabled 2019/10/26 11:42:13 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/26 11:42:13 net packet injection: enabled 2019/10/26 11:42:13 net device setup: enabled 2019/10/26 11:42:13 concurrency sanitizer: enabled 2019/10/26 11:42:14 adding functions to KCSAN blacklist: '__hrtimer_run_queues' 'tomoyo_supervisor' 'pipe_poll' 'find_next_bit' 'pid_update_inode' syzkaller login: [ 49.011686][ T7180] ================================================================== [ 49.019860][ T7180] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 49.026446][ T7180] [ 49.028805][ T7180] write to 0xffff888124b1ce78 of 4 bytes by interrupt on cpu 1: [ 49.036409][ T7180] tcp_queue_rcv+0xe9/0x380 [ 49.040887][ T7180] tcp_rcv_established+0xbf1/0xf50 [ 49.045974][ T7180] tcp_v4_do_rcv+0x381/0x4e0 [ 49.050537][ T7180] tcp_v4_rcv+0x19dc/0x1bb0 [ 49.055136][ T7180] ip_protocol_deliver_rcu+0x4d/0x420 [ 49.060535][ T7180] ip_local_deliver_finish+0x110/0x140 [ 49.065978][ T7180] ip_local_deliver+0x133/0x210 [ 49.070983][ T7180] ip_rcv_finish+0x121/0x160 [ 49.075551][ T7180] ip_rcv+0x18f/0x1a0 [ 49.079519][ T7180] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.085220][ T7180] __netif_receive_skb+0x37/0xf0 [ 49.090172][ T7180] netif_receive_skb_internal+0x59/0x190 [ 49.095820][ T7180] napi_gro_receive+0x28f/0x330 [ 49.100648][ T7180] receive_buf+0x284/0x30b0 [ 49.105118][ T7180] [ 49.107423][ T7180] read to 0xffff888124b1ce78 of 4 bytes by task 7180 on cpu 0: [ 49.114975][ T7180] tcp_poll+0x204/0x6b0 [ 49.119110][ T7180] sock_poll+0xed/0x250 [ 49.123296][ T7180] ep_item_poll.isra.0+0x90/0x190 [ 49.128336][ T7180] ep_send_events_proc+0x113/0x590 [ 49.133421][ T7180] ep_scan_ready_list.constprop.0+0x189/0x500 [ 49.139462][ T7180] ep_poll+0xe3/0x900 [ 49.143416][ T7180] do_epoll_wait+0x162/0x180 [ 49.147984][ T7180] __x64_sys_epoll_pwait+0xcd/0x180 [ 49.153191][ T7180] do_syscall_64+0xcc/0x370 [ 49.157673][ T7180] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.163534][ T7180] [ 49.165834][ T7180] Reported by Kernel Concurrency Sanitizer on: [ 49.171998][ T7180] CPU: 0 PID: 7180 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.179430][ T7180] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.189461][ T7180] ================================================================== [ 49.197502][ T7180] Kernel panic - not syncing: panic_on_warn set ... [ 49.204105][ T7180] CPU: 0 PID: 7180 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.211564][ T7180] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.221591][ T7180] Call Trace: [ 49.224864][ T7180] dump_stack+0xf5/0x159 [ 49.229083][ T7180] panic+0x210/0x640 [ 49.232955][ T7180] ? do_syscall_64+0xcc/0x370 [ 49.237607][ T7180] ? vprintk_func+0x8d/0x140 [ 49.242202][ T7180] kcsan_report.cold+0xc/0x10 [ 49.246858][ T7180] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 49.252378][ T7180] __tsan_read4+0x2c/0x30 [ 49.256696][ T7180] tcp_poll+0x204/0x6b0 [ 49.260833][ T7180] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 49.266268][ T7180] sock_poll+0xed/0x250 [ 49.270401][ T7180] ? sock_read_iter+0x1e0/0x1e0 [ 49.275233][ T7180] ep_item_poll.isra.0+0x90/0x190 [ 49.280255][ T7180] ep_send_events_proc+0x113/0x590 [ 49.285345][ T7180] ? __schedule+0x319/0x640 [ 49.289824][ T7180] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 49.295446][ T7180] ep_scan_ready_list.constprop.0+0x189/0x500 [ 49.301491][ T7180] ? ep_loop_check_proc+0x2f0/0x2f0 [ 49.306664][ T7180] ep_poll+0xe3/0x900 [ 49.310634][ T7180] ? wake_up_q+0x70/0x70 [ 49.314853][ T7180] do_epoll_wait+0x162/0x180 [ 49.319430][ T7180] __x64_sys_epoll_pwait+0xcd/0x180 [ 49.324615][ T7180] do_syscall_64+0xcc/0x370 [ 49.329094][ T7180] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.334971][ T7180] RIP: 0033:0x45b300 [ 49.338855][ T7180] Code: 0f 05 89 44 24 20 c3 cc cc cc 8b 7c 24 08 48 8b 74 24 10 8b 54 24 18 44 8b 54 24 1c 49 c7 c0 00 00 00 00 b8 19 01 00 00 0f 05 <89> 44 24 20 c3 cc cc cc cc cc cc cc cc cc cc cc 8b 7c 24 08 48 c7 [ 49.358435][ T7180] RSP: 002b:000000c42016d860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 49.366821][ T7180] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 49.374767][ T7180] RDX: 0000000000000080 RSI: 000000c42016d8a0 RDI: 0000000000000004 [ 49.382713][ T7180] RBP: 000000c42016dea0 R08: 0000000000000000 R09: 000000c420001e00 [ 49.390664][ T7180] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000000 [ 49.398620][ T7180] R13: 00000000000000f6 R14: 0000000000000076 R15: 0000000000000080 [ 49.408035][ T7180] Kernel Offset: disabled [ 49.412363][ T7180] Rebooting in 86400 seconds..