[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.499618][ T25] audit: type=1800 audit(1570191947.779:25): pid=7014 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.519543][ T25] audit: type=1800 audit(1570191947.779:26): pid=7014 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.541410][ T25] audit: type=1800 audit(1570191947.779:27): pid=7014 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 '10.128.10.23' (ECDSA) to the list of known hosts. 2019/10/04 12:25:56 fuzzer started 2019/10/04 12:25:57 dialing manager at 10.128.0.105:38119 2019/10/04 12:25:57 syscalls: 2523 2019/10/04 12:25:57 code coverage: enabled 2019/10/04 12:25:57 comparison tracing: enabled 2019/10/04 12:25:57 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:25:57 setuid sandbox: enabled 2019/10/04 12:25:57 namespace sandbox: enabled 2019/10/04 12:25:57 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:25:57 fault injection: enabled 2019/10/04 12:25:57 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:25:57 net packet injection: enabled 2019/10/04 12:25:57 net device setup: enabled 2019/10/04 12:25:57 concurrency sanitizer: enabled syzkaller login: [ 47.275082][ T7179] ================================================================== [ 47.283319][ T7179] BUG: KCSAN: data-race in tcp_add_backlog+0x4a0/0xcc0 and tcp_grow_window.isra.0+0x6b/0x480 [ 47.293537][ T7179] [ 47.295844][ T7179] write to 0xffff88812344b2ec of 4 bytes by interrupt on cpu 1: [ 47.303461][ T7179] tcp_add_backlog+0x4a0/0xcc0 [ 47.308275][ T7179] tcp_v4_rcv+0x1aba/0x1bf0 [ 47.312776][ T7179] ip_protocol_deliver_rcu+0x51/0x470 [ 47.318133][ T7179] ip_local_deliver_finish+0x110/0x140 [ 47.323579][ T7179] ip_local_deliver+0x133/0x210 [ 47.328408][ T7179] ip_rcv_finish+0x121/0x160 [ 47.332974][ T7179] ip_rcv+0x18f/0x1a0 [ 47.336935][ T7179] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.342647][ T7179] __netif_receive_skb+0x37/0xf0 [ 47.347567][ T7179] netif_receive_skb_internal+0x59/0x190 [ 47.353189][ T7179] napi_gro_receive+0x28f/0x330 [ 47.358311][ T7179] receive_buf+0x284/0x30b0 [ 47.362852][ T7179] virtnet_poll+0x436/0x7d0 [ 47.367358][ T7179] net_rx_action+0x3ae/0xa50 [ 47.371920][ T7179] [ 47.374229][ T7179] read to 0xffff88812344b2ec of 4 bytes by task 7179 on cpu 0: [ 47.381891][ T7179] tcp_grow_window.isra.0+0x6b/0x480 [ 47.387156][ T7179] tcp_event_data_recv+0x68f/0x990 [ 47.392248][ T7179] tcp_rcv_established+0xbfe/0xf50 [ 47.397401][ T7179] tcp_v4_do_rcv+0x381/0x4e0 [ 47.401970][ T7179] __release_sock+0x135/0x1e0 [ 47.406622][ T7179] release_sock+0x61/0x160 [ 47.411013][ T7179] tcp_recvmsg+0x63b/0x1a30 [ 47.416727][ T7179] inet_recvmsg+0xbb/0x250 [ 47.421132][ T7179] sock_recvmsg+0x92/0xb0 [ 47.425439][ T7179] sock_read_iter+0x15f/0x1e0 [ 47.430096][ T7179] new_sync_read+0x389/0x4f0 [ 47.434662][ T7179] __vfs_read+0xb1/0xc0 [ 47.438793][ T7179] vfs_read+0x143/0x2c0 [ 47.442917][ T7179] [ 47.445218][ T7179] Reported by Kernel Concurrency Sanitizer on: [ 47.451355][ T7179] CPU: 0 PID: 7179 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.458522][ T7179] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.468636][ T7179] ================================================================== [ 47.476669][ T7179] Kernel panic - not syncing: panic_on_warn set ... [ 47.483836][ T7179] CPU: 0 PID: 7179 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.490924][ T7179] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.500963][ T7179] Call Trace: [ 47.504234][ T7179] dump_stack+0xf5/0x159 [ 47.508472][ T7179] panic+0x209/0x639 [ 47.513305][ T7179] ? vprintk_func+0x8d/0x140 [ 47.517877][ T7179] kcsan_report.cold+0x57/0xeb [ 47.522627][ T7179] __kcsan_setup_watchpoint+0x342/0x500 [ 47.528152][ T7179] __tsan_read4+0x2c/0x30 [ 47.532468][ T7179] tcp_grow_window.isra.0+0x6b/0x480 [ 47.537733][ T7179] tcp_event_data_recv+0x68f/0x990 [ 47.542822][ T7179] tcp_rcv_established+0xbfe/0xf50 [ 47.547915][ T7179] ? ipv4_dst_check+0xc6/0xf0 [ 47.552570][ T7179] tcp_v4_do_rcv+0x381/0x4e0 [ 47.557138][ T7179] __release_sock+0x135/0x1e0 [ 47.561795][ T7179] release_sock+0x61/0x160 [ 47.566197][ T7179] tcp_recvmsg+0x63b/0x1a30 [ 47.570680][ T7179] ? __const_udelay+0x36/0x40 [ 47.575329][ T7179] ? __udelay+0x10/0x20 [ 47.579481][ T7179] inet_recvmsg+0xbb/0x250 [ 47.583887][ T7179] ? __tsan_read8+0x2c/0x30 [ 47.588546][ T7179] ? inet_sendpage+0x100/0x100 [ 47.593284][ T7179] sock_recvmsg+0x92/0xb0 [ 47.597588][ T7179] sock_read_iter+0x15f/0x1e0 [ 47.602245][ T7179] new_sync_read+0x389/0x4f0 [ 47.606826][ T7179] __vfs_read+0xb1/0xc0 [ 47.610969][ T7179] vfs_read+0x143/0x2c0 [ 47.615110][ T7179] ksys_read+0xd5/0x1b0 [ 47.619246][ T7179] __x64_sys_read+0x4c/0x60 [ 47.623736][ T7179] do_syscall_64+0xcf/0x2f0 [ 47.628218][ T7179] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.634101][ T7179] RIP: 0033:0x47c530 [ 47.637978][ T7179] 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 [ 47.657748][ T7179] RSP: 002b:000000c4204e57d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.666177][ T7179] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.674243][ T7179] RDX: 0000000000001000 RSI: 000000c4203be000 RDI: 0000000000000003 [ 47.682388][ T7179] RBP: 000000c4204e5830 R08: 0000000000000000 R09: 0000000000000000 [ 47.690437][ T7179] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 47.698400][ T7179] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 47.707780][ T7179] Kernel Offset: disabled [ 47.712104][ T7179] Rebooting in 86400 seconds..