[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 37.761210][ T25] audit: type=1800 audit(1570192019.638:25): pid=7157 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 37.801644][ T25] audit: type=1800 audit(1570192019.648:26): pid=7157 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 37.821701][ T25] audit: type=1800 audit(1570192019.648:27): pid=7157 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 '10.128.0.13' (ECDSA) to the list of known hosts. 2019/10/04 12:27:19 fuzzer started 2019/10/04 12:27:21 dialing manager at 10.128.0.105:38119 2019/10/04 12:27:22 syscalls: 2523 2019/10/04 12:27:22 code coverage: enabled 2019/10/04 12:27:22 comparison tracing: enabled 2019/10/04 12:27:22 extra coverage: extra coverage is not supported by the kernel 2019/10/04 12:27:22 setuid sandbox: enabled 2019/10/04 12:27:22 namespace sandbox: enabled 2019/10/04 12:27:22 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/04 12:27:22 fault injection: enabled 2019/10/04 12:27:22 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/04 12:27:22 net packet injection: enabled 2019/10/04 12:27:22 net device setup: enabled 2019/10/04 12:27:22 concurrency sanitizer: enabled syzkaller login: [ 60.388919][ T7324] ================================================================== [ 60.397152][ T7324] BUG: KCSAN: data-race in __tcp_select_window+0x6b/0x4d0 and tcp_add_backlog+0x4a0/0xcc0 [ 60.407030][ T7324] [ 60.409350][ T7324] write to 0xffff888121a1d32c of 4 bytes by interrupt on cpu 0: [ 60.416960][ T7324] tcp_add_backlog+0x4a0/0xcc0 [ 60.421702][ T7324] tcp_v4_rcv+0x1aba/0x1bf0 [ 60.426194][ T7324] ip_protocol_deliver_rcu+0x51/0x470 [ 60.431542][ T7324] ip_local_deliver_finish+0x110/0x140 [ 60.436977][ T7324] ip_local_deliver+0x133/0x210 [ 60.441837][ T7324] ip_rcv_finish+0x121/0x160 [ 60.446400][ T7324] ip_rcv+0x18f/0x1a0 [ 60.450358][ T7324] __netif_receive_skb_one_core+0xa7/0xe0 [ 60.456055][ T7324] __netif_receive_skb+0x37/0xf0 [ 60.460977][ T7324] netif_receive_skb_internal+0x59/0x190 [ 60.466592][ T7324] napi_gro_receive+0x28f/0x330 [ 60.471427][ T7324] receive_buf+0x284/0x30b0 [ 60.475905][ T7324] virtnet_poll+0x436/0x7d0 [ 60.480395][ T7324] net_rx_action+0x3ae/0xa50 [ 60.484973][ T7324] [ 60.487285][ T7324] read to 0xffff888121a1d32c of 4 bytes by task 7324 on cpu 1: [ 60.494807][ T7324] __tcp_select_window+0x6b/0x4d0 [ 60.499806][ T7324] __tcp_transmit_skb+0x679/0x1cd0 [ 60.504904][ T7324] __tcp_send_ack+0x246/0x300 [ 60.509558][ T7324] tcp_send_ack+0x34/0x40 [ 60.513861][ T7324] tcp_cleanup_rbuf+0x130/0x360 [ 60.518695][ T7324] tcp_recvmsg+0x633/0x1a30 [ 60.523171][ T7324] inet_recvmsg+0xbb/0x250 [ 60.527562][ T7324] sock_recvmsg+0x92/0xb0 [ 60.531876][ T7324] sock_read_iter+0x15f/0x1e0 [ 60.536530][ T7324] new_sync_read+0x389/0x4f0 [ 60.541095][ T7324] __vfs_read+0xb1/0xc0 [ 60.545225][ T7324] vfs_read+0x143/0x2c0 [ 60.549391][ T7324] ksys_read+0xd5/0x1b0 [ 60.553519][ T7324] [ 60.555822][ T7324] Reported by Kernel Concurrency Sanitizer on: [ 60.561956][ T7324] CPU: 1 PID: 7324 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 60.569037][ T7324] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.579070][ T7324] ================================================================== [ 60.587115][ T7324] Kernel panic - not syncing: panic_on_warn set ... [ 60.593678][ T7324] CPU: 1 PID: 7324 Comm: syz-fuzzer Not tainted 5.3.0+ #0 [ 60.601107][ T7324] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 60.611132][ T7324] Call Trace: [ 60.614413][ T7324] dump_stack+0xf5/0x159 [ 60.618633][ T7324] panic+0x209/0x639 [ 60.622506][ T7324] ? vprintk_func+0x8d/0x140 [ 60.627076][ T7324] kcsan_report.cold+0x57/0xeb [ 60.631832][ T7324] __kcsan_setup_watchpoint+0x342/0x500 [ 60.637363][ T7324] __tsan_read4+0x2c/0x30 [ 60.641672][ T7324] __tcp_select_window+0x6b/0x4d0 [ 60.646686][ T7324] __tcp_transmit_skb+0x679/0x1cd0 [ 60.651791][ T7324] __tcp_send_ack+0x246/0x300 [ 60.656475][ T7324] tcp_send_ack+0x34/0x40 [ 60.660780][ T7324] tcp_cleanup_rbuf+0x130/0x360 [ 60.665605][ T7324] tcp_recvmsg+0x633/0x1a30 [ 60.670092][ T7324] inet_recvmsg+0xbb/0x250 [ 60.674494][ T7324] ? __tsan_read8+0x2c/0x30 [ 60.678984][ T7324] ? inet_sendpage+0x100/0x100 [ 60.683725][ T7324] sock_recvmsg+0x92/0xb0 [ 60.688037][ T7324] sock_read_iter+0x15f/0x1e0 [ 60.692695][ T7324] new_sync_read+0x389/0x4f0 [ 60.697269][ T7324] __vfs_read+0xb1/0xc0 [ 60.701408][ T7324] vfs_read+0x143/0x2c0 [ 60.705541][ T7324] ksys_read+0xd5/0x1b0 [ 60.709675][ T7324] __x64_sys_read+0x4c/0x60 [ 60.714158][ T7324] do_syscall_64+0xcf/0x2f0 [ 60.718644][ T7324] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 60.724518][ T7324] RIP: 0033:0x47c530 [ 60.728394][ T7324] 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 [ 60.748063][ T7324] RSP: 002b:000000c4204f57d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 60.756449][ T7324] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 60.764394][ T7324] RDX: 0000000000001000 RSI: 000000c420306000 RDI: 0000000000000003 [ 60.772339][ T7324] RBP: 000000c4204f5830 R08: 0000000000000000 R09: 0000000000000000 [ 60.780286][ T7324] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000003 [ 60.788233][ T7324] R13: 000000c4200206a8 R14: 0000000000000002 R15: ffffffffffffffff [ 60.797536][ T7324] Kernel Offset: disabled [ 60.801862][ T7324] Rebooting in 86400 seconds..