[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 43.661668][ T25] audit: type=1800 audit(1570192429.788:25): pid=7045 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 43.688896][ T25] audit: type=1800 audit(1570192429.788:26): pid=7045 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 43.715835][ T25] audit: type=1800 audit(1570192429.788:27): pid=7045 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 '10.128.0.201' (ECDSA) to the list of known hosts. 2019/10/04 12:34:00 fuzzer started 2019/10/04 12:34:02 dialing manager at 10.128.0.105:38119 2019/10/04 12:34:02 syscalls: 2523 2019/10/04 12:34:02 code coverage: enabled 2019/10/04 12:34:02 comparison tracing: enabled 2019/10/04 12:34:02 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:34:02 setuid sandbox: enabled 2019/10/04 12:34:02 namespace sandbox: enabled 2019/10/04 12:34:02 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:34:02 fault injection: enabled 2019/10/04 12:34:02 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:34:02 net packet injection: enabled 2019/10/04 12:34:02 net device setup: enabled 2019/10/04 12:34:02 concurrency sanitizer: enabled syzkaller login: [ 57.195132][ T7211] ================================================================== [ 57.203352][ T7211] BUG: KCSAN: data-race in tcp_add_backlog+0x45a/0xcc0 and tcp_recvmsg+0x470/0x1a30 [ 57.212813][ T7211] [ 57.215139][ T7211] write to 0xffff8881264e0138 of 8 bytes by interrupt on cpu 1: [ 57.222756][ T7211] tcp_add_backlog+0x45a/0xcc0 [ 57.227537][ T7211] tcp_v4_rcv+0x1aba/0x1bf0 [ 57.232044][ T7211] ip_protocol_deliver_rcu+0x51/0x470 [ 57.237408][ T7211] ip_local_deliver_finish+0x110/0x140 [ 57.242847][ T7211] ip_local_deliver+0x133/0x210 [ 57.247676][ T7211] ip_rcv_finish+0x121/0x160 [ 57.252241][ T7211] ip_rcv+0x18f/0x1a0 [ 57.256638][ T7211] __netif_receive_skb_one_core+0xa7/0xe0 [ 57.262424][ T7211] __netif_receive_skb+0x37/0xf0 [ 57.267344][ T7211] netif_receive_skb_internal+0x59/0x190 [ 57.273038][ T7211] napi_gro_receive+0x28f/0x330 [ 57.277863][ T7211] receive_buf+0x284/0x30b0 [ 57.282344][ T7211] virtnet_poll+0x436/0x7d0 [ 57.287441][ T7211] net_rx_action+0x3ae/0xa50 [ 57.291999][ T7211] [ 57.294305][ T7211] read to 0xffff8881264e0138 of 8 bytes by task 7211 on cpu 0: [ 57.301824][ T7211] tcp_recvmsg+0x470/0x1a30 [ 57.306312][ T7211] inet_recvmsg+0xbb/0x250 [ 57.310737][ T7211] sock_recvmsg+0x92/0xb0 [ 57.315051][ T7211] sock_read_iter+0x15f/0x1e0 [ 57.319720][ T7211] new_sync_read+0x389/0x4f0 [ 57.324288][ T7211] __vfs_read+0xb1/0xc0 [ 57.328419][ T7211] vfs_read+0x143/0x2c0 [ 57.332549][ T7211] ksys_read+0xd5/0x1b0 [ 57.336679][ T7211] __x64_sys_read+0x4c/0x60 [ 57.341165][ T7211] do_syscall_64+0xcf/0x2f0 [ 57.345664][ T7211] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 57.351535][ T7211] [ 57.353837][ T7211] Reported by Kernel Concurrency Sanitizer on: [ 57.359968][ T7211] CPU: 0 PID: 7211 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 57.367050][ T7211] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.377078][ T7211] ================================================================== [ 57.385112][ T7211] Kernel panic - not syncing: panic_on_warn set ... [ 57.391683][ T7211] CPU: 0 PID: 7211 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 57.398831][ T7211] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 57.408880][ T7211] Call Trace: [ 57.412153][ T7211] dump_stack+0xf5/0x159 [ 57.416388][ T7211] panic+0x209/0x639 [ 57.420273][ T7211] ? vprintk_func+0x8d/0x140 [ 57.424861][ T7211] kcsan_report.cold+0x57/0xeb [ 57.429610][ T7211] __kcsan_setup_watchpoint+0x342/0x500 [ 57.435141][ T7211] __tsan_read8+0x2c/0x30 [ 57.439453][ T7211] tcp_recvmsg+0x470/0x1a30 [ 57.443954][ T7211] inet_recvmsg+0xbb/0x250 [ 57.448347][ T7211] ? __tsan_read8+0x2c/0x30 [ 57.452840][ T7211] ? inet_sendpage+0x100/0x100 [ 57.457580][ T7211] sock_recvmsg+0x92/0xb0 [ 57.461916][ T7211] sock_read_iter+0x15f/0x1e0 [ 57.466582][ T7211] new_sync_read+0x389/0x4f0 [ 57.471165][ T7211] __vfs_read+0xb1/0xc0 [ 57.475317][ T7211] vfs_read+0x143/0x2c0 [ 57.479462][ T7211] ksys_read+0xd5/0x1b0 [ 57.483604][ T7211] __x64_sys_read+0x4c/0x60 [ 57.488101][ T7211] do_syscall_64+0xcf/0x2f0 [ 57.492606][ T7211] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 57.498480][ T7211] RIP: 0033:0x47c530 [ 57.502488][ T7211] 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 [ 57.522069][ T7211] RSP: 002b:000000c4202c97d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 57.530509][ T7211] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 57.538475][ T7211] RDX: 0000000000001000 RSI: 000000c4200d8000 RDI: 0000000000000003 [ 57.546467][ T7211] RBP: 000000c4202c9830 R08: 0000000000000000 R09: 0000000000000000 [ 57.554415][ T7211] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000200 [ 57.562364][ T7211] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 57.571580][ T7211] Kernel Offset: disabled [ 57.575912][ T7211] Rebooting in 86400 seconds..