[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.869974][ T25] audit: type=1800 audit(1570192960.241:25): pid=7031 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.898048][ T25] audit: type=1800 audit(1570192960.241:26): pid=7031 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.918780][ T25] audit: type=1800 audit(1570192960.241:27): pid=7031 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 '10.128.0.2' (ECDSA) to the list of known hosts. 2019/10/04 12:42:49 fuzzer started 2019/10/04 12:42:51 dialing manager at 10.128.0.105:38119 2019/10/04 12:42:51 syscalls: 2523 2019/10/04 12:42:51 code coverage: enabled 2019/10/04 12:42:51 comparison tracing: enabled 2019/10/04 12:42:51 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:42:51 setuid sandbox: enabled 2019/10/04 12:42:51 namespace sandbox: enabled 2019/10/04 12:42:51 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:42:51 fault injection: enabled 2019/10/04 12:42:51 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:42:51 net packet injection: enabled 2019/10/04 12:42:51 net device setup: enabled 2019/10/04 12:42:51 concurrency sanitizer: enabled syzkaller login: [ 48.175832][ T7195] ================================================================== [ 48.184027][ T7195] BUG: KCSAN: data-race in tcp_add_backlog+0x4a0/0xcc0 and tcp_grow_window.isra.0+0x6b/0x480 [ 48.194146][ T7195] [ 48.196483][ T7195] write to 0xffff88812271812c of 4 bytes by interrupt on cpu 0: [ 48.204198][ T7195] tcp_add_backlog+0x4a0/0xcc0 [ 48.208938][ T7195] tcp_v4_rcv+0x1aba/0x1bf0 [ 48.213618][ T7195] ip_protocol_deliver_rcu+0x51/0x470 [ 48.219061][ T7195] ip_local_deliver_finish+0x110/0x140 [ 48.224509][ T7195] ip_local_deliver+0x133/0x210 [ 48.229363][ T7195] ip_rcv_finish+0x121/0x160 [ 48.233927][ T7195] ip_rcv+0x18f/0x1a0 [ 48.237902][ T7195] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.243700][ T7195] __netif_receive_skb+0x37/0xf0 [ 48.248625][ T7195] netif_receive_skb_internal+0x59/0x190 [ 48.254295][ T7195] napi_gro_receive+0x28f/0x330 [ 48.259418][ T7195] receive_buf+0x284/0x30b0 [ 48.264084][ T7195] virtnet_poll+0x436/0x7d0 [ 48.268566][ T7195] net_rx_action+0x3ae/0xa50 [ 48.273128][ T7195] [ 48.275440][ T7195] read to 0xffff88812271812c of 4 bytes by task 7195 on cpu 1: [ 48.282974][ T7195] tcp_grow_window.isra.0+0x6b/0x480 [ 48.288240][ T7195] tcp_event_data_recv+0x68f/0x990 [ 48.293327][ T7195] tcp_rcv_established+0xbfe/0xf50 [ 48.298678][ T7195] tcp_v4_do_rcv+0x381/0x4e0 [ 48.303264][ T7195] __release_sock+0x135/0x1e0 [ 48.307936][ T7195] release_sock+0x61/0x160 [ 48.312329][ T7195] tcp_recvmsg+0x63b/0x1a30 [ 48.316904][ T7195] inet_recvmsg+0xbb/0x250 [ 48.321299][ T7195] sock_recvmsg+0x92/0xb0 [ 48.325607][ T7195] sock_read_iter+0x15f/0x1e0 [ 48.330349][ T7195] new_sync_read+0x389/0x4f0 [ 48.335005][ T7195] __vfs_read+0xb1/0xc0 [ 48.339138][ T7195] vfs_read+0x143/0x2c0 [ 48.343263][ T7195] [ 48.345566][ T7195] Reported by Kernel Concurrency Sanitizer on: [ 48.351799][ T7195] CPU: 1 PID: 7195 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 48.358882][ T7195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.369029][ T7195] ================================================================== [ 48.377941][ T7195] Kernel panic - not syncing: panic_on_warn set ... [ 48.384509][ T7195] CPU: 1 PID: 7195 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 48.391605][ T7195] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.401636][ T7195] Call Trace: [ 48.404909][ T7195] dump_stack+0xf5/0x159 [ 48.409145][ T7195] panic+0x209/0x639 [ 48.413035][ T7195] ? vprintk_func+0x8d/0x140 [ 48.417608][ T7195] kcsan_report.cold+0x57/0xeb [ 48.422717][ T7195] __kcsan_setup_watchpoint+0x342/0x500 [ 48.428243][ T7195] __tsan_read4+0x2c/0x30 [ 48.432556][ T7195] tcp_grow_window.isra.0+0x6b/0x480 [ 48.437824][ T7195] tcp_event_data_recv+0x68f/0x990 [ 48.442930][ T7195] tcp_rcv_established+0xbfe/0xf50 [ 48.448053][ T7195] ? ipv4_dst_check+0xc6/0xf0 [ 48.452942][ T7195] tcp_v4_do_rcv+0x381/0x4e0 [ 48.457530][ T7195] __release_sock+0x135/0x1e0 [ 48.462449][ T7195] release_sock+0x61/0x160 [ 48.466848][ T7195] tcp_recvmsg+0x63b/0x1a30 [ 48.471333][ T7195] ? __const_udelay+0x36/0x40 [ 48.476008][ T7195] inet_recvmsg+0xbb/0x250 [ 48.480404][ T7195] ? __tsan_read8+0x2c/0x30 [ 48.484901][ T7195] ? inet_sendpage+0x100/0x100 [ 48.489652][ T7195] sock_recvmsg+0x92/0xb0 [ 48.494395][ T7195] sock_read_iter+0x15f/0x1e0 [ 48.499055][ T7195] new_sync_read+0x389/0x4f0 [ 48.508927][ T7195] __vfs_read+0xb1/0xc0 [ 48.513068][ T7195] vfs_read+0x143/0x2c0 [ 48.517208][ T7195] ksys_read+0xd5/0x1b0 [ 48.521346][ T7195] __x64_sys_read+0x4c/0x60 [ 48.525835][ T7195] do_syscall_64+0xcf/0x2f0 [ 48.530413][ T7195] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.536300][ T7195] RIP: 0033:0x47c530 [ 48.540178][ T7195] 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 [ 48.559770][ T7195] RSP: 002b:000000c4204fb7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.568158][ T7195] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.576121][ T7195] RDX: 0000000000001000 RSI: 000000c42031e000 RDI: 0000000000000003 [ 48.584080][ T7195] RBP: 000000c4204fb830 R08: 0000000000000000 R09: 0000000000000000 [ 48.592047][ T7195] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000004 [ 48.599995][ T7195] R13: 000000c4200209b0 R14: 0000000000000002 R15: ffffffffffffffff [ 48.609424][ T7195] Kernel Offset: disabled [ 48.614025][ T7195] Rebooting in 86400 seconds..