[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.682492][ T26] audit: type=1800 audit(1571767064.092:25): pid=7147 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.722620][ T26] audit: type=1800 audit(1571767064.092:26): pid=7147 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.750348][ T26] audit: type=1800 audit(1571767064.092:27): pid=7147 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 '10.128.1.55' (ECDSA) to the list of known hosts. 2019/10/22 17:57:53 fuzzer started 2019/10/22 17:57:55 dialing manager at 10.128.0.105:33369 2019/10/22 17:57:55 syscalls: 2524 2019/10/22 17:57:55 code coverage: enabled 2019/10/22 17:57:55 comparison tracing: enabled 2019/10/22 17:57:55 extra coverage: extra coverage is not supported by the kernel 2019/10/22 17:57:55 setuid sandbox: enabled 2019/10/22 17:57:55 namespace sandbox: enabled 2019/10/22 17:57:55 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 17:57:55 fault injection: enabled 2019/10/22 17:57:55 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 17:57:55 net packet injection: enabled 2019/10/22 17:57:55 net device setup: enabled 2019/10/22 17:57:55 concurrency sanitizer: enabled syzkaller login: [ 48.152322][ T7312] ================================================================== [ 48.160480][ T7312] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 48.168194][ T7312] [ 48.170507][ T7312] write to 0xffff8881264449ec of 4 bytes by interrupt on cpu 1: [ 48.178289][ T7312] tcp_add_backlog+0x4a0/0xcc0 [ 48.183058][ T7312] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.187541][ T7312] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.192906][ T7312] ip_local_deliver_finish+0x110/0x140 [ 48.198340][ T7312] ip_local_deliver+0x133/0x210 [ 48.203166][ T7312] ip_rcv_finish+0x121/0x160 [ 48.207729][ T7312] ip_rcv+0x18f/0x1a0 [ 48.211777][ T7312] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.217474][ T7312] __netif_receive_skb+0x37/0xf0 [ 48.222388][ T7312] netif_receive_skb_internal+0x59/0x190 [ 48.227999][ T7312] napi_gro_receive+0x28f/0x330 [ 48.232854][ T7312] receive_buf+0x284/0x30b0 [ 48.237338][ T7312] virtnet_poll+0x436/0x7d0 [ 48.241819][ T7312] net_rx_action+0x3ae/0xa90 [ 48.246378][ T7312] [ 48.248689][ T7312] read to 0xffff8881264449ec of 4 bytes by task 7312 on cpu 0: [ 48.256211][ T7312] __tcp_select_window+0x6b/0x4d0 [ 48.261237][ T7312] __tcp_transmit_skb+0x700/0x1d60 [ 48.268246][ T7312] __tcp_send_ack+0x246/0x300 [ 48.272910][ T7312] tcp_send_ack+0x34/0x40 [ 48.277229][ T7312] tcp_cleanup_rbuf+0x130/0x360 [ 48.282235][ T7312] tcp_recvmsg+0x633/0x1a30 [ 48.286716][ T7312] inet_recvmsg+0xbb/0x250 [ 48.291112][ T7312] sock_recvmsg+0x92/0xb0 [ 48.295512][ T7312] sock_read_iter+0x15f/0x1e0 [ 48.300789][ T7312] new_sync_read+0x389/0x4f0 [ 48.305358][ T7312] __vfs_read+0xb1/0xc0 [ 48.309493][ T7312] vfs_read+0x143/0x2c0 [ 48.313642][ T7312] ksys_read+0xd5/0x1b0 [ 48.317768][ T7312] [ 48.320085][ T7312] Reported by Kernel Concurrency Sanitizer on: [ 48.326321][ T7312] CPU: 0 PID: 7312 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.333762][ T7312] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.343805][ T7312] ================================================================== [ 48.351944][ T7312] Kernel panic - not syncing: panic_on_warn set ... [ 48.358509][ T7312] CPU: 0 PID: 7312 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.365937][ T7312] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.376057][ T7312] Call Trace: [ 48.381333][ T7312] dump_stack+0xf5/0x159 [ 48.385559][ T7312] panic+0x210/0x640 [ 48.389458][ T7312] ? sock_read_iter+0x15f/0x1e0 [ 48.394314][ T7312] ? vprintk_func+0x8d/0x140 [ 48.398901][ T7312] kcsan_report.cold+0xc/0x10 [ 48.403564][ T7312] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.409102][ T7312] __tsan_read4+0x2c/0x30 [ 48.413411][ T7312] __tcp_select_window+0x6b/0x4d0 [ 48.418486][ T7312] __tcp_transmit_skb+0x700/0x1d60 [ 48.423607][ T7312] __tcp_send_ack+0x246/0x300 [ 48.428288][ T7312] tcp_send_ack+0x34/0x40 [ 48.432626][ T7312] tcp_cleanup_rbuf+0x130/0x360 [ 48.437483][ T7312] tcp_recvmsg+0x633/0x1a30 [ 48.442285][ T7312] inet_recvmsg+0xbb/0x250 [ 48.446678][ T7312] ? __tsan_read8+0x2c/0x30 [ 48.451161][ T7312] ? inet_sendpage+0x100/0x100 [ 48.456264][ T7312] sock_recvmsg+0x92/0xb0 [ 48.460673][ T7312] sock_read_iter+0x15f/0x1e0 [ 48.465330][ T7312] new_sync_read+0x389/0x4f0 [ 48.469918][ T7312] __vfs_read+0xb1/0xc0 [ 48.474055][ T7312] vfs_read+0x143/0x2c0 [ 48.478205][ T7312] ksys_read+0xd5/0x1b0 [ 48.482354][ T7312] __x64_sys_read+0x4c/0x60 [ 48.486847][ T7312] do_syscall_64+0xcc/0x370 [ 48.492405][ T7312] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.498279][ T7312] RIP: 0033:0x47c530 [ 48.502168][ T7312] 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 [ 48.521893][ T7312] RSP: 002b:000000c4206247d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.530300][ T7312] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.538384][ T7312] RDX: 0000000000001000 RSI: 000000c42031a000 RDI: 0000000000000003 [ 48.546352][ T7312] RBP: 000000c420624830 R08: 0000000000000000 R09: 0000000000000000 [ 48.554307][ T7312] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000007 [ 48.562358][ T7312] R13: 000000c420083400 R14: 0000000000000004 R15: ffffffffffffffff [ 48.571873][ T7312] Kernel Offset: disabled [ 48.576228][ T7312] Rebooting in 86400 seconds..