[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.399495][ T25] audit: type=1800 audit(1571767911.458:25): pid=7036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.444172][ T25] audit: type=1800 audit(1571767911.458:26): pid=7036 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.467628][ T25] audit: type=1800 audit(1571767911.458:27): pid=7036 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 '10.128.10.37' (ECDSA) to the list of known hosts. 2019/10/22 18:12:02 fuzzer started 2019/10/22 18:12:03 dialing manager at 10.128.0.105:33369 2019/10/22 18:12:03 syscalls: 2524 2019/10/22 18:12:03 code coverage: enabled 2019/10/22 18:12:03 comparison tracing: enabled 2019/10/22 18:12:03 extra coverage: extra coverage is not supported by the kernel 2019/10/22 18:12:03 setuid sandbox: enabled 2019/10/22 18:12:03 namespace sandbox: enabled 2019/10/22 18:12:03 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 18:12:03 fault injection: enabled 2019/10/22 18:12:03 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 18:12:03 net packet injection: enabled 2019/10/22 18:12:03 net device setup: enabled 2019/10/22 18:12:03 concurrency sanitizer: enabled syzkaller login: [ 46.981458][ T7199] ================================================================== [ 46.989594][ T7199] BUG: KCSAN: data-race in tcp_add_backlog / tcp_grow_window.isra.0 [ 46.997670][ T7199] [ 46.999980][ T7199] write to 0xffff8881264f932c of 4 bytes by interrupt on cpu 0: [ 47.007593][ T7199] tcp_add_backlog+0x4a0/0xcc0 [ 47.012342][ T7199] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.016855][ T7199] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.022201][ T7199] ip_local_deliver_finish+0x110/0x140 [ 47.027634][ T7199] ip_local_deliver+0x133/0x210 [ 47.032467][ T7199] ip_rcv_finish+0x121/0x160 [ 47.037026][ T7199] ip_rcv+0x18f/0x1a0 [ 47.040993][ T7199] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.046684][ T7199] __netif_receive_skb+0x37/0xf0 [ 47.051596][ T7199] netif_receive_skb_internal+0x59/0x190 [ 47.057200][ T7199] napi_gro_receive+0x28f/0x330 [ 47.062027][ T7199] receive_buf+0x284/0x30b0 [ 47.066505][ T7199] virtnet_poll+0x436/0x7d0 [ 47.070990][ T7199] net_rx_action+0x3ae/0xa90 [ 47.075548][ T7199] [ 47.077864][ T7199] read to 0xffff8881264f932c of 4 bytes by task 7199 on cpu 1: [ 47.085381][ T7199] tcp_grow_window.isra.0+0x6b/0x480 [ 47.090639][ T7199] tcp_event_data_recv+0x68f/0x990 [ 47.095731][ T7199] tcp_rcv_established+0xbfe/0xf50 [ 47.100827][ T7199] tcp_v4_do_rcv+0x381/0x4e0 [ 47.105439][ T7199] __release_sock+0x135/0x1e0 [ 47.110093][ T7199] release_sock+0x61/0x160 [ 47.114494][ T7199] tcp_recvmsg+0x63b/0x1a30 [ 47.119023][ T7199] inet_recvmsg+0xbb/0x250 [ 47.123445][ T7199] sock_recvmsg+0x92/0xb0 [ 47.127761][ T7199] sock_read_iter+0x15f/0x1e0 [ 47.132417][ T7199] new_sync_read+0x389/0x4f0 [ 47.136983][ T7199] __vfs_read+0xb1/0xc0 [ 47.141115][ T7199] vfs_read+0x143/0x2c0 [ 47.145243][ T7199] [ 47.147545][ T7199] Reported by Kernel Concurrency Sanitizer on: [ 47.153675][ T7199] CPU: 1 PID: 7199 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.161098][ T7199] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.171128][ T7199] ================================================================== [ 47.179171][ T7199] Kernel panic - not syncing: panic_on_warn set ... [ 47.185733][ T7199] CPU: 1 PID: 7199 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.193156][ T7199] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.203971][ T7199] Call Trace: [ 47.207250][ T7199] dump_stack+0xf5/0x159 [ 47.211521][ T7199] panic+0x210/0x640 [ 47.215398][ T7199] ? sock_recvmsg+0x92/0xb0 [ 47.219883][ T7199] ? vprintk_func+0x8d/0x140 [ 47.224458][ T7199] kcsan_report.cold+0xc/0x10 [ 47.229115][ T7199] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.234642][ T7199] __tsan_read4+0x2c/0x30 [ 47.238962][ T7199] tcp_grow_window.isra.0+0x6b/0x480 [ 47.244228][ T7199] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.249851][ T7199] tcp_event_data_recv+0x68f/0x990 [ 47.254951][ T7199] tcp_rcv_established+0xbfe/0xf50 [ 47.260043][ T7199] ? ipv4_dst_check+0xc6/0xf0 [ 47.264753][ T7199] tcp_v4_do_rcv+0x381/0x4e0 [ 47.269327][ T7199] __release_sock+0x135/0x1e0 [ 47.274447][ T7199] release_sock+0x61/0x160 [ 47.278843][ T7199] tcp_recvmsg+0x63b/0x1a30 [ 47.283334][ T7199] inet_recvmsg+0xbb/0x250 [ 47.287754][ T7199] ? __tsan_read8+0x2c/0x30 [ 47.292235][ T7199] ? inet_sendpage+0x100/0x100 [ 47.296993][ T7199] sock_recvmsg+0x92/0xb0 [ 47.301303][ T7199] sock_read_iter+0x15f/0x1e0 [ 47.305963][ T7199] new_sync_read+0x389/0x4f0 [ 47.310537][ T7199] __vfs_read+0xb1/0xc0 [ 47.314674][ T7199] vfs_read+0x143/0x2c0 [ 47.318909][ T7199] ksys_read+0xd5/0x1b0 [ 47.323056][ T7199] __x64_sys_read+0x4c/0x60 [ 47.327553][ T7199] do_syscall_64+0xcc/0x370 [ 47.332038][ T7199] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.337904][ T7199] RIP: 0033:0x47c530 [ 47.341783][ T7199] 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 [ 47.361365][ T7199] RSP: 002b:000000c4202c57d8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 47.369785][ T7199] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 47.377732][ T7199] RDX: 0000000000001000 RSI: 000000c4200a2000 RDI: 0000000000000003 [ 47.385680][ T7199] RBP: 000000c4202c5830 R08: 0000000000000000 R09: 0000000000000000 [ 47.393634][ T7199] R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000020 [ 47.401579][ T7199] R13: ffffffffffffffff R14: 0000000000000010 R15: ffffffffffffffff [ 47.410879][ T7199] Kernel Offset: disabled [ 47.415199][ T7199] Rebooting in 86400 seconds..