[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.518572][ T25] audit: type=1800 audit(1570192895.347:25): pid=7009 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.538523][ T25] audit: type=1800 audit(1570192895.347:26): pid=7009 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.560051][ T25] audit: type=1800 audit(1570192895.347:27): pid=7009 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 '10.128.0.226' (ECDSA) to the list of known hosts. 2019/10/04 12:41:45 fuzzer started 2019/10/04 12:41:46 dialing manager at 10.128.0.105:38119 2019/10/04 12:41:46 syscalls: 2523 2019/10/04 12:41:46 code coverage: enabled 2019/10/04 12:41:46 comparison tracing: enabled 2019/10/04 12:41:46 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:41:46 setuid sandbox: enabled 2019/10/04 12:41:46 namespace sandbox: enabled 2019/10/04 12:41:46 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:41:46 fault injection: enabled 2019/10/04 12:41:46 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:41:46 net packet injection: enabled 2019/10/04 12:41:46 net device setup: enabled 2019/10/04 12:41:46 concurrency sanitizer: enabled syzkaller login: [ 46.849591][ T7163] ================================================================== [ 46.857931][ T7163] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 46.867799][ T7163] [ 46.870117][ T7163] write to 0xffff8881253892ec of 4 bytes by interrupt on cpu 0: [ 46.877721][ T7163] tcp_add_backlog+0x4a0/0xcc0 [ 46.882457][ T7163] tcp_v4_rcv+0x1aba/0x1bf0 [ 46.886937][ T7163] ip_protocol_deliver_rcu+0x51/0x470 [ 46.892283][ T7163] ip_local_deliver_finish+0x110/0x140 [ 46.897710][ T7163] ip_local_deliver+0x133/0x210 [ 46.902529][ T7163] ip_rcv_finish+0x121/0x160 [ 46.907087][ T7163] ip_rcv+0x18f/0x1a0 [ 46.911047][ T7163] __netif_receive_skb_one_core+0xa7/0xe0 [ 46.916739][ T7163] __netif_receive_skb+0x37/0xf0 [ 46.921645][ T7163] netif_receive_skb_internal+0x59/0x190 [ 46.927247][ T7163] napi_gro_receive+0x28f/0x330 [ 46.932069][ T7163] receive_buf+0x284/0x30b0 [ 46.936545][ T7163] virtnet_poll+0x436/0x7d0 [ 46.941017][ T7163] net_rx_action+0x3ae/0xa50 [ 46.945641][ T7163] [ 46.947947][ T7163] read to 0xffff8881253892ec of 4 bytes by task 7163 on cpu 1: [ 46.955463][ T7163] __tcp_select_window+0x6b/0x4d0 [ 46.960460][ T7163] __tcp_transmit_skb+0x679/0x1cd0 [ 46.965544][ T7163] __tcp_send_ack+0x246/0x300 [ 46.970205][ T7163] tcp_send_ack+0x34/0x40 [ 46.974503][ T7163] tcp_cleanup_rbuf+0x130/0x360 [ 46.979340][ T7163] tcp_recvmsg+0x633/0x1a30 [ 46.983815][ T7163] inet_recvmsg+0xbb/0x250 [ 46.988219][ T7163] sock_recvmsg+0x92/0xb0 [ 46.992519][ T7163] sock_read_iter+0x15f/0x1e0 [ 46.997167][ T7163] new_sync_read+0x389/0x4f0 [ 47.001731][ T7163] __vfs_read+0xb1/0xc0 [ 47.005856][ T7163] vfs_read+0x143/0x2c0 [ 47.009983][ T7163] ksys_read+0xd5/0x1b0 [ 47.014102][ T7163] [ 47.016430][ T7163] Reported by Kernel Concurrency Sanitizer on: [ 47.022566][ T7163] CPU: 1 PID: 7163 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.029641][ T7163] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.039668][ T7163] ================================================================== [ 47.047697][ T7163] Kernel panic - not syncing: panic_on_warn set ... [ 47.054253][ T7163] CPU: 1 PID: 7163 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 47.061329][ T7163] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.071351][ T7163] Call Trace: [ 47.074632][ T7163] dump_stack+0xf5/0x159 [ 47.078848][ T7163] panic+0x209/0x639 [ 47.082720][ T7163] ? vprintk_func+0x8d/0x140 [ 47.087287][ T7163] kcsan_report.cold+0x57/0xeb [ 47.092024][ T7163] __kcsan_setup_watchpoint+0x342/0x500 [ 47.097542][ T7163] __tsan_read4+0x2c/0x30 [ 47.101846][ T7163] __tcp_select_window+0x6b/0x4d0 [ 47.106846][ T7163] __tcp_transmit_skb+0x679/0x1cd0 [ 47.111939][ T7163] __tcp_send_ack+0x246/0x300 [ 47.116590][ T7163] tcp_send_ack+0x34/0x40 [ 47.120895][ T7163] tcp_cleanup_rbuf+0x130/0x360 [ 47.125721][ T7163] tcp_recvmsg+0x633/0x1a30 [ 47.130248][ T7163] inet_recvmsg+0xbb/0x250 [ 47.134671][ T7163] ? __tsan_read8+0x2c/0x30 [ 47.139151][ T7163] ? inet_sendpage+0x100/0x100 [ 47.143918][ T7163] sock_recvmsg+0x92/0xb0 [ 47.148221][ T7163] sock_read_iter+0x15f/0x1e0 [ 47.152897][ T7163] new_sync_read+0x389/0x4f0 [ 47.157465][ T7163] __vfs_read+0xb1/0xc0 [ 47.161597][ T7163] vfs_read+0x143/0x2c0 [ 47.165750][ T7163] ksys_read+0xd5/0x1b0 [ 47.169881][ T7163] __x64_sys_read+0x4c/0x60 [ 47.174374][ T7163] do_syscall_64+0xcf/0x2f0 [ 47.178855][ T7163] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.184722][ T7163] RIP: 0033:0x47c530 [ 47.188590][ T7163] 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 [ 47.208179][ T7163] RSP: 002b:000000c4203af810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 47.216564][ T7163] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.224511][ T7163] RDX: 0000000000001000 RSI: 000000c42030e000 RDI: 0000000000000003 [ 47.232455][ T7163] RBP: 000000c4203af868 R08: 0000000000000000 R09: 0000000000000000 [ 47.240486][ T7163] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000009 [ 47.248429][ T7163] R13: 000000c4200233e0 R14: 0000000000000004 R15: ffffffffffffffff [ 47.257683][ T7163] Kernel Offset: disabled [ 47.262006][ T7163] Rebooting in 86400 seconds..