[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.936998][ T25] audit: type=1800 audit(1571763829.965:25): pid=7140 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.975963][ T25] audit: type=1800 audit(1571763829.965:26): pid=7140 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.996918][ T25] audit: type=1800 audit(1571763829.975:27): pid=7140 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 '10.128.1.56' (ECDSA) to the list of known hosts. 2019/10/22 17:04:00 fuzzer started 2019/10/22 17:04:01 dialing manager at 10.128.0.105:33369 2019/10/22 17:04:01 syscalls: 2524 2019/10/22 17:04:01 code coverage: enabled 2019/10/22 17:04:01 comparison tracing: enabled 2019/10/22 17:04:01 extra coverage: extra coverage is not supported by the kernel 2019/10/22 17:04:01 setuid sandbox: enabled 2019/10/22 17:04:01 namespace sandbox: enabled 2019/10/22 17:04:01 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 17:04:01 fault injection: enabled 2019/10/22 17:04:01 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 17:04:01 net packet injection: enabled 2019/10/22 17:04:01 net device setup: enabled 2019/10/22 17:04:01 concurrency sanitizer: enabled syzkaller login: [ 48.109860][ T7296] ================================================================== [ 48.118020][ T7296] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 48.126005][ T7296] [ 48.128338][ T7296] write to 0xffff88812683812c of 4 bytes by interrupt on cpu 0: [ 48.136390][ T7296] tcp_add_backlog+0x4a0/0xcc0 [ 48.141620][ T7296] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.146115][ T7296] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.151484][ T7296] ip_local_deliver_finish+0x110/0x140 [ 48.156946][ T7296] ip_local_deliver+0x133/0x210 [ 48.161784][ T7296] ip_rcv_finish+0x121/0x160 [ 48.166570][ T7296] ip_rcv+0x18f/0x1a0 [ 48.170801][ T7296] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.176943][ T7296] __netif_receive_skb+0x37/0xf0 [ 48.182010][ T7296] netif_receive_skb_internal+0x59/0x190 [ 48.187790][ T7296] napi_gro_receive+0x28f/0x330 [ 48.192775][ T7296] receive_buf+0x284/0x30b0 [ 48.197617][ T7296] virtnet_poll+0x436/0x7d0 [ 48.202575][ T7296] net_rx_action+0x3ae/0xa90 [ 48.207330][ T7296] [ 48.209813][ T7296] read to 0xffff88812683812c of 4 bytes by task 7296 on cpu 1: [ 48.218128][ T7296] __tcp_select_window+0x6b/0x4d0 [ 48.223791][ T7296] __tcp_transmit_skb+0x700/0x1d60 [ 48.229289][ T7296] __tcp_send_ack+0x246/0x300 [ 48.234472][ T7296] tcp_send_ack+0x34/0x40 [ 48.239171][ T7296] tcp_cleanup_rbuf+0x130/0x360 [ 48.244796][ T7296] tcp_recvmsg+0x633/0x1a30 [ 48.250689][ T7296] inet_recvmsg+0xbb/0x250 [ 48.255409][ T7296] sock_recvmsg+0x92/0xb0 [ 48.260214][ T7296] sock_read_iter+0x15f/0x1e0 [ 48.265227][ T7296] new_sync_read+0x389/0x4f0 [ 48.270065][ T7296] __vfs_read+0xb1/0xc0 [ 48.274433][ T7296] vfs_read+0x143/0x2c0 [ 48.278580][ T7296] ksys_read+0xd5/0x1b0 [ 48.282889][ T7296] [ 48.285406][ T7296] Reported by Kernel Concurrency Sanitizer on: [ 48.292173][ T7296] CPU: 1 PID: 7296 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.299765][ T7296] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.310480][ T7296] ================================================================== [ 48.319696][ T7296] Kernel panic - not syncing: panic_on_warn set ... [ 48.328073][ T7296] CPU: 1 PID: 7296 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.336077][ T7296] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.346701][ T7296] Call Trace: [ 48.349999][ T7296] dump_stack+0xf5/0x159 [ 48.354488][ T7296] panic+0x210/0x640 [ 48.358728][ T7296] ? sock_read_iter+0x15f/0x1e0 [ 48.363977][ T7296] ? vprintk_func+0x8d/0x140 [ 48.368838][ T7296] kcsan_report.cold+0xc/0x10 [ 48.373665][ T7296] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.379522][ T7296] __tsan_read4+0x2c/0x30 [ 48.384215][ T7296] __tcp_select_window+0x6b/0x4d0 [ 48.389473][ T7296] __tcp_transmit_skb+0x700/0x1d60 [ 48.395119][ T7296] __tcp_send_ack+0x246/0x300 [ 48.399801][ T7296] tcp_send_ack+0x34/0x40 [ 48.404163][ T7296] tcp_cleanup_rbuf+0x130/0x360 [ 48.409014][ T7296] tcp_recvmsg+0x633/0x1a30 [ 48.413931][ T7296] inet_recvmsg+0xbb/0x250 [ 48.418436][ T7296] ? __tsan_read8+0x2c/0x30 [ 48.423419][ T7296] ? inet_sendpage+0x100/0x100 [ 48.428448][ T7296] sock_recvmsg+0x92/0xb0 [ 48.433017][ T7296] sock_read_iter+0x15f/0x1e0 [ 48.437829][ T7296] new_sync_read+0x389/0x4f0 [ 48.442943][ T7296] __vfs_read+0xb1/0xc0 [ 48.447365][ T7296] vfs_read+0x143/0x2c0 [ 48.451688][ T7296] ksys_read+0xd5/0x1b0 [ 48.456114][ T7296] __x64_sys_read+0x4c/0x60 [ 48.460940][ T7296] do_syscall_64+0xcc/0x370 [ 48.465442][ T7296] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.471333][ T7296] RIP: 0033:0x47c530 [ 48.475307][ T7296] 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 [ 48.495451][ T7296] RSP: 002b:000000c4203937d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.504510][ T7296] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.512715][ T7296] RDX: 0000000000001000 RSI: 000000c4203d0000 RDI: 0000000000000003 [ 48.521255][ T7296] RBP: 000000c420393830 R08: 0000000000000000 R09: 0000000000000000 [ 48.529766][ T7296] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000008 [ 48.538006][ T7296] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 48.548285][ T7296] Kernel Offset: disabled [ 48.554342][ T7296] Rebooting in 86400 seconds..