[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.096929][ T26] audit: type=1800 audit(1570471284.585:25): pid=7057 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.131847][ T26] audit: type=1800 audit(1570471284.585:26): pid=7057 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.157155][ T26] audit: type=1800 audit(1570471284.585:27): pid=7057 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 '10.128.0.113' (ECDSA) to the list of known hosts. 2019/10/07 18:01:36 fuzzer started 2019/10/07 18:01:37 dialing manager at 10.128.0.105:39369 2019/10/07 18:01:37 syscalls: 2523 2019/10/07 18:01:37 code coverage: enabled 2019/10/07 18:01:37 comparison tracing: enabled 2019/10/07 18:01:37 extra coverage: extra coverage is not supported by the kernel 2019/10/07 18:01:37 setuid sandbox: enabled 2019/10/07 18:01:37 namespace sandbox: enabled 2019/10/07 18:01:37 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/07 18:01:37 fault injection: enabled 2019/10/07 18:01:37 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/07 18:01:37 net packet injection: enabled 2019/10/07 18:01:37 net device setup: enabled 2019/10/07 18:01:37 concurrency sanitizer: enabled syzkaller login: [ 48.153931][ T7221] ================================================================== [ 48.162103][ T7221] BUG: KCSAN: data-race in tcp_add_backlog / tcp_rcv_space_adjust [ 48.169927][ T7221] [ 48.172281][ T7221] read to 0xffff8881249dd30c of 4 bytes by interrupt on cpu 1: [ 48.179815][ T7221] tcp_add_backlog+0x43/0xcc0 [ 48.184466][ T7221] tcp_v4_rcv+0x1aba/0x1bf0 [ 48.188949][ T7221] ip_protocol_deliver_rcu+0x51/0x470 [ 48.194296][ T7221] ip_local_deliver_finish+0x110/0x140 [ 48.199742][ T7221] ip_local_deliver+0x133/0x210 [ 48.204570][ T7221] ip_rcv_finish+0x121/0x160 [ 48.209222][ T7221] ip_rcv+0x18f/0x1a0 [ 48.213186][ T7221] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.218887][ T7221] __netif_receive_skb+0x37/0xf0 [ 48.223811][ T7221] netif_receive_skb_internal+0x59/0x190 [ 48.229420][ T7221] napi_gro_receive+0x28f/0x330 [ 48.234249][ T7221] receive_buf+0x284/0x30b0 [ 48.238731][ T7221] virtnet_poll+0x436/0x7d0 [ 48.243206][ T7221] net_rx_action+0x3ae/0xa50 [ 48.247764][ T7221] [ 48.250072][ T7221] write to 0xffff8881249dd30c of 4 bytes by task 7221 on cpu 0: [ 48.257689][ T7221] tcp_rcv_space_adjust+0x40f/0x4c0 [ 48.262874][ T7221] tcp_recvmsg+0xdaa/0x1a30 [ 48.267361][ T7221] inet_recvmsg+0xbb/0x250 [ 48.271765][ T7221] sock_recvmsg+0x92/0xb0 [ 48.276071][ T7221] sock_read_iter+0x15f/0x1e0 [ 48.280725][ T7221] new_sync_read+0x389/0x4f0 [ 48.285291][ T7221] __vfs_read+0xb1/0xc0 [ 48.289422][ T7221] vfs_read+0x143/0x2c0 [ 48.293552][ T7221] ksys_read+0xd5/0x1b0 [ 48.297692][ T7221] __x64_sys_read+0x4c/0x60 [ 48.302189][ T7221] do_syscall_64+0xcf/0x2f0 [ 48.306673][ T7221] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.312535][ T7221] [ 48.314839][ T7221] Reported by Kernel Concurrency Sanitizer on: [ 48.320969][ T7221] CPU: 0 PID: 7221 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 48.328087][ T7221] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.338124][ T7221] ================================================================== [ 48.346164][ T7221] Kernel panic - not syncing: panic_on_warn set ... [ 48.352733][ T7221] CPU: 0 PID: 7221 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 48.359815][ T7221] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.369846][ T7221] Call Trace: [ 48.373118][ T7221] dump_stack+0xf5/0x159 [ 48.377345][ T7221] panic+0x209/0x639 [ 48.381238][ T7221] ? vprintk_func+0x8d/0x140 [ 48.385809][ T7221] kcsan_report.cold+0x57/0xeb [ 48.390553][ T7221] __kcsan_setup_watchpoint+0x342/0x500 [ 48.396089][ T7221] __tsan_write4+0x32/0x40 [ 48.400485][ T7221] tcp_rcv_space_adjust+0x40f/0x4c0 [ 48.405665][ T7221] tcp_recvmsg+0xdaa/0x1a30 [ 48.410170][ T7221] inet_recvmsg+0xbb/0x250 [ 48.414562][ T7221] ? __tsan_read8+0x2c/0x30 [ 48.419059][ T7221] ? inet_sendpage+0x100/0x100 [ 48.423801][ T7221] sock_recvmsg+0x92/0xb0 [ 48.428121][ T7221] sock_read_iter+0x15f/0x1e0 [ 48.432781][ T7221] new_sync_read+0x389/0x4f0 [ 48.437364][ T7221] __vfs_read+0xb1/0xc0 [ 48.441511][ T7221] vfs_read+0x143/0x2c0 [ 48.445654][ T7221] ksys_read+0xd5/0x1b0 [ 48.449792][ T7221] __x64_sys_read+0x4c/0x60 [ 48.454286][ T7221] do_syscall_64+0xcf/0x2f0 [ 48.458774][ T7221] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.464655][ T7221] RIP: 0033:0x47c530 [ 48.468536][ T7221] 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 [ 48.488123][ T7221] RSP: 002b:000000c4203157d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.496512][ T7221] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.504476][ T7221] RDX: 0000000000001000 RSI: 000000c4203ec000 RDI: 0000000000000003 [ 48.512429][ T7221] RBP: 000000c420315830 R08: 0000000000000000 R09: 0000000000000000 [ 48.520383][ T7221] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000010 [ 48.528363][ T7221] R13: ffffffffffffffff R14: 0000000000000010 R15: ffffffffffffffff [ 48.537596][ T7221] Kernel Offset: disabled [ 48.541941][ T7221] Rebooting in 86400 seconds..