[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 33.997758][ T25] audit: type=1800 audit(1572046847.263:25): pid=7079 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.024925][ T25] audit: type=1800 audit(1572046847.263:26): pid=7079 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.055213][ T25] audit: type=1800 audit(1572046847.263:27): pid=7079 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 '10.128.1.34' (ECDSA) to the list of known hosts. 2019/10/25 23:40:58 fuzzer started 2019/10/25 23:40:59 dialing manager at 10.128.0.105:32811 2019/10/25 23:40:59 syscalls: 2533 2019/10/25 23:40:59 code coverage: enabled 2019/10/25 23:40:59 comparison tracing: enabled 2019/10/25 23:40:59 extra coverage: extra coverage is not supported by the kernel 2019/10/25 23:40:59 setuid sandbox: enabled 2019/10/25 23:40:59 namespace sandbox: enabled 2019/10/25 23:40:59 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/25 23:40:59 fault injection: enabled 2019/10/25 23:40:59 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/25 23:40:59 net packet injection: enabled 2019/10/25 23:40:59 net device setup: enabled 2019/10/25 23:40:59 concurrency sanitizer: enabled 2019/10/25 23:41:00 adding functions to KCSAN blacklist: '__hrtimer_run_queues' 'pid_update_inode' 'common_perm_cond' 'echo_char' 'ktime_get_real_seconds' 'tomoyo_supervisor' syzkaller login: [ 47.961753][ T7252] ================================================================== [ 47.969873][ T7252] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 47.977561][ T7252] [ 47.980001][ T7252] write to 0xffff8881240332ec of 4 bytes by interrupt on cpu 0: [ 47.987628][ T7252] tcp_add_backlog+0xb91/0xcc0 [ 47.992376][ T7252] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.996855][ T7252] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.002294][ T7252] ip_local_deliver_finish+0x110/0x140 [ 48.007726][ T7252] ip_local_deliver+0x133/0x210 [ 48.012548][ T7252] ip_rcv_finish+0x121/0x160 [ 48.017119][ T7252] ip_rcv+0x18f/0x1a0 [ 48.021076][ T7252] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.027030][ T7252] __netif_receive_skb+0x37/0xf0 [ 48.032055][ T7252] netif_receive_skb_internal+0x59/0x190 [ 48.037675][ T7252] napi_gro_receive+0x28f/0x330 [ 48.042514][ T7252] receive_buf+0x284/0x30b0 [ 48.046991][ T7252] virtnet_poll+0x436/0x7d0 [ 48.051469][ T7252] net_rx_action+0x3ae/0xa90 [ 48.056039][ T7252] [ 48.058346][ T7252] read to 0xffff8881240332ec of 4 bytes by task 7252 on cpu 1: [ 48.065873][ T7252] __tcp_select_window+0x6b/0x4d0 [ 48.070874][ T7252] __tcp_transmit_skb+0x700/0x1d60 [ 48.075965][ T7252] __tcp_send_ack+0x246/0x300 [ 48.080623][ T7252] tcp_send_ack+0x34/0x40 [ 48.084945][ T7252] tcp_cleanup_rbuf+0x130/0x360 [ 48.089773][ T7252] tcp_recvmsg+0x633/0x1a30 [ 48.094346][ T7252] inet_recvmsg+0xbb/0x250 [ 48.098756][ T7252] sock_recvmsg+0x92/0xb0 [ 48.103072][ T7252] sock_read_iter+0x15f/0x1e0 [ 48.107730][ T7252] new_sync_read+0x389/0x4f0 [ 48.112296][ T7252] __vfs_read+0xb1/0xc0 [ 48.116424][ T7252] vfs_read+0x143/0x2c0 [ 48.120554][ T7252] ksys_read+0xd5/0x1b0 [ 48.124678][ T7252] [ 48.126977][ T7252] Reported by Kernel Concurrency Sanitizer on: [ 48.133108][ T7252] CPU: 1 PID: 7252 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.140533][ T7252] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.150562][ T7252] ================================================================== [ 48.158599][ T7252] Kernel panic - not syncing: panic_on_warn set ... [ 48.165160][ T7252] CPU: 1 PID: 7252 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.172596][ T7252] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.182623][ T7252] Call Trace: [ 48.185890][ T7252] dump_stack+0xf5/0x159 [ 48.190113][ T7252] panic+0x210/0x640 [ 48.193988][ T7252] ? sock_read_iter+0x15f/0x1e0 [ 48.198816][ T7252] ? vprintk_func+0x8d/0x140 [ 48.203384][ T7252] kcsan_report.cold+0xc/0x10 [ 48.208038][ T7252] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.213560][ T7252] __tsan_read4+0x2c/0x30 [ 48.217864][ T7252] __tcp_select_window+0x6b/0x4d0 [ 48.222866][ T7252] __tcp_transmit_skb+0x700/0x1d60 [ 48.227959][ T7252] __tcp_send_ack+0x246/0x300 [ 48.232628][ T7252] tcp_send_ack+0x34/0x40 [ 48.236939][ T7252] tcp_cleanup_rbuf+0x130/0x360 [ 48.241766][ T7252] tcp_recvmsg+0x633/0x1a30 [ 48.246284][ T7252] inet_recvmsg+0xbb/0x250 [ 48.250689][ T7252] ? __tsan_read8+0x2c/0x30 [ 48.255174][ T7252] ? inet_sendpage+0x100/0x100 [ 48.259926][ T7252] sock_recvmsg+0x92/0xb0 [ 48.264247][ T7252] sock_read_iter+0x15f/0x1e0 [ 48.268905][ T7252] new_sync_read+0x389/0x4f0 [ 48.273476][ T7252] __vfs_read+0xb1/0xc0 [ 48.277610][ T7252] vfs_read+0x143/0x2c0 [ 48.281744][ T7252] ksys_read+0xd5/0x1b0 [ 48.285878][ T7252] __x64_sys_read+0x4c/0x60 [ 48.290544][ T7252] do_syscall_64+0xcc/0x370 [ 48.295033][ T7252] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.300903][ T7252] RIP: 0033:0x47c530 [ 48.304866][ T7252] 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 [ 48.324467][ T7252] RSP: 002b:000000c4202f17d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.332854][ T7252] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.340801][ T7252] RDX: 0000000000001000 RSI: 000000c4203a2000 RDI: 0000000000000003 [ 48.348756][ T7252] RBP: 000000c4202f1830 R08: 0000000000000000 R09: 0000000000000000 [ 48.356701][ T7252] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000010 [ 48.364648][ T7252] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 48.373940][ T7252] Kernel Offset: disabled [ 48.378266][ T7252] Rebooting in 86400 seconds..