[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.749298][ T25] audit: type=1800 audit(1571754115.067:25): pid=7058 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.777183][ T25] audit: type=1800 audit(1571754115.067:26): pid=7058 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.812459][ T25] audit: type=1800 audit(1571754115.067:27): pid=7058 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 '10.128.0.127' (ECDSA) to the list of known hosts. 2019/10/22 14:22:05 fuzzer started 2019/10/22 14:22:07 dialing manager at 10.128.0.105:33369 2019/10/22 14:22:07 syscalls: 2524 2019/10/22 14:22:07 code coverage: enabled 2019/10/22 14:22:07 comparison tracing: enabled 2019/10/22 14:22:07 extra coverage: extra coverage is not supported by the kernel 2019/10/22 14:22:07 setuid sandbox: enabled 2019/10/22 14:22:07 namespace sandbox: enabled 2019/10/22 14:22:07 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 14:22:07 fault injection: enabled 2019/10/22 14:22:07 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 14:22:07 net packet injection: enabled 2019/10/22 14:22:07 net device setup: enabled 2019/10/22 14:22:07 concurrency sanitizer: enabled syzkaller login: [ 48.485901][ T7225] ================================================================== [ 48.494098][ T7225] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 48.501790][ T7225] [ 48.504109][ T7225] write to 0xffff8881242932ec of 4 bytes by interrupt on cpu 0: [ 48.511718][ T7225] tcp_add_backlog+0x4a0/0xcc0 [ 48.516460][ T7225] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.520941][ T7225] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.526290][ T7225] ip_local_deliver_finish+0x110/0x140 [ 48.531724][ T7225] ip_local_deliver+0x133/0x210 [ 48.536552][ T7225] ip_rcv_finish+0x121/0x160 [ 48.548062][ T7225] ip_rcv+0x18f/0x1a0 [ 48.552037][ T7225] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.557732][ T7225] __netif_receive_skb+0x37/0xf0 [ 48.562645][ T7225] netif_receive_skb_internal+0x59/0x190 [ 48.568264][ T7225] napi_gro_receive+0x28f/0x330 [ 48.573095][ T7225] receive_buf+0x284/0x30b0 [ 48.577586][ T7225] virtnet_poll+0x436/0x7d0 [ 48.582065][ T7225] net_rx_action+0x3ae/0xa90 [ 48.586624][ T7225] [ 48.588931][ T7225] read to 0xffff8881242932ec of 4 bytes by task 7225 on cpu 1: [ 48.596448][ T7225] __tcp_select_window+0x6b/0x4d0 [ 48.601467][ T7225] __tcp_transmit_skb+0x700/0x1d60 [ 48.606555][ T7225] __tcp_send_ack+0x246/0x300 [ 48.611221][ T7225] tcp_send_ack+0x34/0x40 [ 48.615558][ T7225] tcp_cleanup_rbuf+0x130/0x360 [ 48.620386][ T7225] tcp_recvmsg+0x633/0x1a30 [ 48.624873][ T7225] inet_recvmsg+0xbb/0x250 [ 48.629283][ T7225] sock_recvmsg+0x92/0xb0 [ 48.633588][ T7225] sock_read_iter+0x15f/0x1e0 [ 48.638248][ T7225] new_sync_read+0x389/0x4f0 [ 48.642816][ T7225] __vfs_read+0xb1/0xc0 [ 48.646950][ T7225] vfs_read+0x143/0x2c0 [ 48.651083][ T7225] ksys_read+0xd5/0x1b0 [ 48.655210][ T7225] [ 48.657514][ T7225] Reported by Kernel Concurrency Sanitizer on: [ 48.663645][ T7225] CPU: 1 PID: 7225 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.671072][ T7225] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.681118][ T7225] ================================================================== [ 48.689159][ T7225] Kernel panic - not syncing: panic_on_warn set ... [ 48.695740][ T7225] CPU: 1 PID: 7225 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.703190][ T7225] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.713319][ T7225] Call Trace: [ 48.716606][ T7225] dump_stack+0xf5/0x159 [ 48.720835][ T7225] panic+0x210/0x640 [ 48.724712][ T7225] ? sock_read_iter+0x15f/0x1e0 [ 48.729561][ T7225] ? vprintk_func+0x8d/0x140 [ 48.734148][ T7225] kcsan_report.cold+0xc/0x10 [ 48.738815][ T7225] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.744342][ T7225] __tsan_read4+0x2c/0x30 [ 48.748651][ T7225] __tcp_select_window+0x6b/0x4d0 [ 48.753654][ T7225] __tcp_transmit_skb+0x700/0x1d60 [ 48.758750][ T7225] __tcp_send_ack+0x246/0x300 [ 48.763406][ T7225] tcp_send_ack+0x34/0x40 [ 48.767725][ T7225] tcp_cleanup_rbuf+0x130/0x360 [ 48.772557][ T7225] tcp_recvmsg+0x633/0x1a30 [ 48.777047][ T7225] inet_recvmsg+0xbb/0x250 [ 48.781440][ T7225] ? __tsan_read8+0x2c/0x30 [ 48.785921][ T7225] ? inet_sendpage+0x100/0x100 [ 48.790665][ T7225] sock_recvmsg+0x92/0xb0 [ 48.794999][ T7225] sock_read_iter+0x15f/0x1e0 [ 48.799657][ T7225] new_sync_read+0x389/0x4f0 [ 48.804230][ T7225] __vfs_read+0xb1/0xc0 [ 48.808364][ T7225] vfs_read+0x143/0x2c0 [ 48.812519][ T7225] ksys_read+0xd5/0x1b0 [ 48.816665][ T7225] __x64_sys_read+0x4c/0x60 [ 48.821153][ T7225] do_syscall_64+0xcc/0x370 [ 48.825637][ T7225] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.831507][ T7225] RIP: 0033:0x47c530 [ 48.835433][ T7225] 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 [ 48.855088][ T7225] RSP: 002b:000000c4202fb7d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.863483][ T7225] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.871521][ T7225] RDX: 0000000000001000 RSI: 000000c4200d6000 RDI: 0000000000000003 [ 48.879471][ T7225] RBP: 000000c4202fb830 R08: 0000000000000000 R09: 0000000000000000 [ 48.887420][ T7225] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000010 [ 48.895387][ T7225] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.904654][ T7225] Kernel Offset: disabled [ 48.909000][ T7225] Rebooting in 86400 seconds..