[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 40.913070][ T26] audit: type=1800 audit(1571760911.573:25): pid=6987 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 40.970358][ T26] audit: type=1800 audit(1571760911.573:26): pid=6987 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 40.993568][ T26] audit: type=1800 audit(1571760911.583:27): pid=6987 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 '10.128.1.40' (ECDSA) to the list of known hosts. 2019/10/22 16:15:23 fuzzer started 2019/10/22 16:15:24 dialing manager at 10.128.0.105:33369 2019/10/22 16:15:24 syscalls: 2524 2019/10/22 16:15:24 code coverage: enabled 2019/10/22 16:15:24 comparison tracing: enabled 2019/10/22 16:15:24 extra coverage: extra coverage is not supported by the kernel 2019/10/22 16:15:24 setuid sandbox: enabled 2019/10/22 16:15:24 namespace sandbox: enabled 2019/10/22 16:15:24 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 16:15:24 fault injection: enabled 2019/10/22 16:15:24 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 16:15:24 net packet injection: enabled 2019/10/22 16:15:24 net device setup: enabled 2019/10/22 16:15:24 concurrency sanitizer: enabled syzkaller login: [ 53.866856][ T7149] ================================================================== [ 53.874991][ T7149] BUG: KCSAN: data-race in __tcp_select_window / tcp_add_backlog [ 53.882694][ T7149] [ 53.885034][ T7149] write to 0xffff88811eab212c of 4 bytes by interrupt on cpu 1: [ 53.892766][ T7149] tcp_add_backlog+0x4a0/0xcc0 [ 53.897521][ T7149] tcp_v4_rcv+0x1a60/0x1bb0 [ 53.902011][ T7149] ip_protocol_deliver_rcu+0x4d/0x420 [ 53.907364][ T7149] ip_local_deliver_finish+0x110/0x140 [ 53.912801][ T7149] ip_local_deliver+0x133/0x210 [ 53.917630][ T7149] ip_rcv_finish+0x121/0x160 [ 53.922194][ T7149] ip_rcv+0x18f/0x1a0 [ 53.926152][ T7149] __netif_receive_skb_one_core+0xa7/0xe0 [ 53.931845][ T7149] __netif_receive_skb+0x37/0xf0 [ 53.936768][ T7149] netif_receive_skb_internal+0x59/0x190 [ 53.942375][ T7149] napi_gro_receive+0x28f/0x330 [ 53.947202][ T7149] receive_buf+0x284/0x30b0 [ 53.951692][ T7149] virtnet_poll+0x436/0x7d0 [ 53.956183][ T7149] net_rx_action+0x3ae/0xa90 [ 53.960752][ T7149] [ 53.963080][ T7149] read to 0xffff88811eab212c of 4 bytes by task 7149 on cpu 0: [ 53.971040][ T7149] __tcp_select_window+0x6b/0x4d0 [ 53.976038][ T7149] __tcp_transmit_skb+0x700/0x1d60 [ 53.981139][ T7149] __tcp_send_ack+0x246/0x300 [ 53.985790][ T7149] tcp_send_ack+0x34/0x40 [ 53.990098][ T7149] tcp_cleanup_rbuf+0x130/0x360 [ 53.994925][ T7149] tcp_recvmsg+0x633/0x1a30 [ 53.999406][ T7149] inet_recvmsg+0xbb/0x250 [ 54.003798][ T7149] sock_recvmsg+0x92/0xb0 [ 54.008122][ T7149] sock_read_iter+0x15f/0x1e0 [ 54.012773][ T7149] new_sync_read+0x389/0x4f0 [ 54.017340][ T7149] __vfs_read+0xb1/0xc0 [ 54.021470][ T7149] vfs_read+0x143/0x2c0 [ 54.025616][ T7149] ksys_read+0xd5/0x1b0 [ 54.029738][ T7149] [ 54.032052][ T7149] Reported by Kernel Concurrency Sanitizer on: [ 54.038193][ T7149] CPU: 0 PID: 7149 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 54.045620][ T7149] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.055757][ T7149] ================================================================== [ 54.063795][ T7149] Kernel panic - not syncing: panic_on_warn set ... [ 54.070975][ T7149] CPU: 0 PID: 7149 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 54.079367][ T7149] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 54.089395][ T7149] Call Trace: [ 54.092663][ T7149] dump_stack+0xf5/0x159 [ 54.096895][ T7149] panic+0x210/0x640 [ 54.100769][ T7149] ? sock_read_iter+0x15f/0x1e0 [ 54.105609][ T7149] ? vprintk_func+0x8d/0x140 [ 54.110191][ T7149] kcsan_report.cold+0xc/0x10 [ 54.114851][ T7149] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 54.120372][ T7149] __tsan_read4+0x2c/0x30 [ 54.124693][ T7149] __tcp_select_window+0x6b/0x4d0 [ 54.129698][ T7149] __tcp_transmit_skb+0x700/0x1d60 [ 54.134793][ T7149] __tcp_send_ack+0x246/0x300 [ 54.139535][ T7149] tcp_send_ack+0x34/0x40 [ 54.143856][ T7149] tcp_cleanup_rbuf+0x130/0x360 [ 54.148686][ T7149] tcp_recvmsg+0x633/0x1a30 [ 54.153457][ T7149] inet_recvmsg+0xbb/0x250 [ 54.157953][ T7149] ? __tsan_read8+0x2c/0x30 [ 54.162448][ T7149] ? inet_sendpage+0x100/0x100 [ 54.167462][ T7149] sock_recvmsg+0x92/0xb0 [ 54.171771][ T7149] sock_read_iter+0x15f/0x1e0 [ 54.176427][ T7149] new_sync_read+0x389/0x4f0 [ 54.181003][ T7149] __vfs_read+0xb1/0xc0 [ 54.185138][ T7149] vfs_read+0x143/0x2c0 [ 54.189273][ T7149] ksys_read+0xd5/0x1b0 [ 54.193547][ T7149] __x64_sys_read+0x4c/0x60 [ 54.198032][ T7149] do_syscall_64+0xcc/0x370 [ 54.202515][ T7149] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 54.208393][ T7149] RIP: 0033:0x47c530 [ 54.212267][ T7149] 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 [ 54.232378][ T7149] RSP: 002b:000000c4204f1810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 54.240764][ T7149] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 54.248816][ T7149] RDX: 0000000000001000 RSI: 000000c4203ca000 RDI: 0000000000000003 [ 54.256764][ T7149] RBP: 000000c4204f1868 R08: 0000000000000000 R09: 0000000000000000 [ 54.264730][ T7149] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008 [ 54.272677][ T7149] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 54.281847][ T7149] Kernel Offset: disabled [ 54.286253][ T7149] Rebooting in 86400 seconds..