[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.744649][ T26] audit: type=1800 audit(1571773020.052:25): pid=7149 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.771932][ T26] audit: type=1800 audit(1571773020.052:26): pid=7149 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.799178][ T26] audit: type=1800 audit(1571773020.052:27): pid=7149 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 '10.128.10.6' (ECDSA) to the list of known hosts. 2019/10/22 19:37:11 fuzzer started 2019/10/22 19:37:12 dialing manager at 10.128.0.105:33369 2019/10/22 19:37:12 syscalls: 2524 2019/10/22 19:37:12 code coverage: enabled 2019/10/22 19:37:12 comparison tracing: enabled 2019/10/22 19:37:12 extra coverage: extra coverage is not supported by the kernel 2019/10/22 19:37:12 setuid sandbox: enabled 2019/10/22 19:37:12 namespace sandbox: enabled 2019/10/22 19:37:12 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 19:37:12 fault injection: enabled 2019/10/22 19:37:12 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 19:37:12 net packet injection: enabled 2019/10/22 19:37:12 net device setup: enabled 2019/10/22 19:37:12 concurrency sanitizer: enabled syzkaller login: [ 47.972559][ T7319] ================================================================== [ 47.980726][ T7319] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 47.988824][ T7319] [ 47.991139][ T7319] write to 0xffff8881229209ec of 4 bytes by interrupt on cpu 0: [ 47.998746][ T7319] tcp_add_backlog+0x4a0/0xcc0 [ 48.003485][ T7319] tcp_v4_rcv+0x1a60/0x1bb0 [ 48.007965][ T7319] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.013323][ T7319] ip_local_deliver_finish+0x110/0x140 [ 48.019028][ T7319] ip_local_deliver+0x133/0x210 [ 48.023862][ T7319] ip_rcv_finish+0x121/0x160 [ 48.028432][ T7319] ip_rcv+0x18f/0x1a0 [ 48.032394][ T7319] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.038188][ T7319] __netif_receive_skb+0x37/0xf0 [ 48.043115][ T7319] netif_receive_skb_internal+0x59/0x190 [ 48.048723][ T7319] napi_gro_receive+0x28f/0x330 [ 48.053552][ T7319] receive_buf+0x284/0x30b0 [ 48.058031][ T7319] virtnet_poll+0x436/0x7d0 [ 48.062519][ T7319] net_rx_action+0x3ae/0xa90 [ 48.067076][ T7319] [ 48.069384][ T7319] read to 0xffff8881229209ec of 4 bytes by task 7319 on cpu 1: [ 48.076988][ T7319] tcp_grow_window.isra.0+0x6b/0x480 [ 48.082262][ T7319] tcp_event_data_recv+0x68f/0x990 [ 48.087346][ T7319] tcp_rcv_established+0xbfe/0xf50 [ 48.092433][ T7319] tcp_v4_do_rcv+0x381/0x4e0 [ 48.097007][ T7319] __release_sock+0x135/0x1e0 [ 48.101689][ T7319] release_sock+0x61/0x160 [ 48.106085][ T7319] tcp_recvmsg+0x63b/0x1a30 [ 48.110574][ T7319] inet_recvmsg+0xbb/0x250 [ 48.114977][ T7319] sock_recvmsg+0x92/0xb0 [ 48.119368][ T7319] sock_read_iter+0x15f/0x1e0 [ 48.124020][ T7319] new_sync_read+0x389/0x4f0 [ 48.128761][ T7319] __vfs_read+0xb1/0xc0 [ 48.133014][ T7319] vfs_read+0x143/0x2c0 [ 48.137275][ T7319] [ 48.139583][ T7319] Reported by Kernel Concurrency Sanitizer on: [ 48.145822][ T7319] CPU: 1 PID: 7319 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.153347][ T7319] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.163471][ T7319] ================================================================== [ 48.171775][ T7319] Kernel panic - not syncing: panic_on_warn set ... [ 48.178785][ T7319] CPU: 1 PID: 7319 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.186228][ T7319] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.196729][ T7319] Call Trace: [ 48.200035][ T7319] dump_stack+0xf5/0x159 [ 48.204450][ T7319] panic+0x210/0x640 [ 48.208434][ T7319] ? sock_recvmsg+0x92/0xb0 [ 48.213121][ T7319] ? vprintk_func+0x8d/0x140 [ 48.218074][ T7319] kcsan_report.cold+0xc/0x10 [ 48.222757][ T7319] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.228308][ T7319] __tsan_read4+0x2c/0x30 [ 48.232738][ T7319] tcp_grow_window.isra.0+0x6b/0x480 [ 48.238094][ T7319] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.243817][ T7319] tcp_event_data_recv+0x68f/0x990 [ 48.249095][ T7319] tcp_rcv_established+0xbfe/0xf50 [ 48.254366][ T7319] ? ipv4_dst_check+0xc6/0xf0 [ 48.259039][ T7319] tcp_v4_do_rcv+0x381/0x4e0 [ 48.263998][ T7319] __release_sock+0x135/0x1e0 [ 48.268663][ T7319] release_sock+0x61/0x160 [ 48.273327][ T7319] tcp_recvmsg+0x63b/0x1a30 [ 48.277935][ T7319] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.283736][ T7319] inet_recvmsg+0xbb/0x250 [ 48.288291][ T7319] ? __tsan_read8+0x2c/0x30 [ 48.292787][ T7319] ? inet_sendpage+0x100/0x100 [ 48.297711][ T7319] sock_recvmsg+0x92/0xb0 [ 48.302123][ T7319] sock_read_iter+0x15f/0x1e0 [ 48.306798][ T7319] new_sync_read+0x389/0x4f0 [ 48.311471][ T7319] __vfs_read+0xb1/0xc0 [ 48.315724][ T7319] vfs_read+0x143/0x2c0 [ 48.319877][ T7319] ksys_read+0xd5/0x1b0 [ 48.324136][ T7319] __x64_sys_read+0x4c/0x60 [ 48.328650][ T7319] do_syscall_64+0xcc/0x370 [ 48.333136][ T7319] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.339021][ T7319] RIP: 0033:0x47c530 [ 48.343010][ T7319] 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 [ 48.362866][ T7319] RSP: 002b:000000c4200517d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 48.371527][ T7319] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.379767][ T7319] RDX: 0000000000001000 RSI: 000000c420314000 RDI: 0000000000000003 [ 48.387811][ T7319] RBP: 000000c420051830 R08: 0000000000000000 R09: 0000000000000000 [ 48.395939][ T7319] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000100 [ 48.404375][ T7319] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.414226][ T7319] Kernel Offset: disabled [ 48.418562][ T7319] Rebooting in 86400 seconds..