[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.140914][ T25] audit: type=1800 audit(1571782958.229:25): pid=7101 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.160663][ T25] audit: type=1800 audit(1571782958.229:26): pid=7101 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.180576][ T25] audit: type=1800 audit(1571782958.229:27): pid=7101 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 '10.128.1.58' (ECDSA) to the list of known hosts. 2019/10/22 22:22:49 fuzzer started 2019/10/22 22:22:51 dialing manager at 10.128.0.105:33369 2019/10/22 22:22:51 syscalls: 2524 2019/10/22 22:22:51 code coverage: enabled 2019/10/22 22:22:51 comparison tracing: enabled 2019/10/22 22:22:51 extra coverage: extra coverage is not supported by the kernel 2019/10/22 22:22:51 setuid sandbox: enabled 2019/10/22 22:22:51 namespace sandbox: enabled 2019/10/22 22:22:51 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 22:22:51 fault injection: enabled 2019/10/22 22:22:51 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 22:22:51 net packet injection: enabled 2019/10/22 22:22:51 net device setup: enabled 2019/10/22 22:22:51 concurrency sanitizer: enabled syzkaller login: [ 49.820794][ T7257] ================================================================== [ 49.828968][ T7257] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 49.836002][ T7257] [ 49.838321][ T7257] write to 0xffff888122ec92f8 of 8 bytes by interrupt on cpu 0: [ 49.845929][ T7257] tcp_add_backlog+0x45a/0xcc0 [ 49.850668][ T7257] tcp_v4_rcv+0x1a60/0x1bb0 [ 49.855159][ T7257] ip_protocol_deliver_rcu+0x4d/0x420 [ 49.860658][ T7257] ip_local_deliver_finish+0x110/0x140 [ 49.866113][ T7257] ip_local_deliver+0x133/0x210 [ 49.870940][ T7257] ip_rcv_finish+0x121/0x160 [ 49.875602][ T7257] ip_rcv+0x18f/0x1a0 [ 49.879573][ T7257] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.885277][ T7257] __netif_receive_skb+0x37/0xf0 [ 49.890194][ T7257] netif_receive_skb_internal+0x59/0x190 [ 49.895806][ T7257] napi_gro_receive+0x28f/0x330 [ 49.900633][ T7257] receive_buf+0x284/0x30b0 [ 49.905124][ T7257] virtnet_poll+0x436/0x7d0 [ 49.909615][ T7257] net_rx_action+0x3ae/0xa90 [ 49.914173][ T7257] [ 49.916484][ T7257] read to 0xffff888122ec92f8 of 8 bytes by task 7257 on cpu 1: [ 49.924012][ T7257] tcp_recvmsg+0x470/0x1a30 [ 49.928490][ T7257] inet_recvmsg+0xbb/0x250 [ 49.932884][ T7257] sock_recvmsg+0x92/0xb0 [ 49.937203][ T7257] sock_read_iter+0x15f/0x1e0 [ 49.941882][ T7257] new_sync_read+0x389/0x4f0 [ 49.946456][ T7257] __vfs_read+0xb1/0xc0 [ 49.950592][ T7257] vfs_read+0x143/0x2c0 [ 49.954726][ T7257] ksys_read+0xd5/0x1b0 [ 49.958862][ T7257] __x64_sys_read+0x4c/0x60 [ 49.963360][ T7257] do_syscall_64+0xcc/0x370 [ 49.967841][ T7257] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.973714][ T7257] [ 49.976978][ T7257] Reported by Kernel Concurrency Sanitizer on: [ 49.983176][ T7257] CPU: 1 PID: 7257 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.990609][ T7257] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.000689][ T7257] ================================================================== [ 50.008729][ T7257] Kernel panic - not syncing: panic_on_warn set ... [ 50.015293][ T7257] CPU: 1 PID: 7257 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 50.022719][ T7257] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 50.032747][ T7257] Call Trace: [ 50.036019][ T7257] dump_stack+0xf5/0x159 [ 50.040412][ T7257] panic+0x210/0x640 [ 50.044286][ T7257] ? __x64_sys_read+0x4c/0x60 [ 50.048938][ T7257] ? vprintk_func+0x8d/0x140 [ 50.053507][ T7257] kcsan_report.cold+0xc/0x10 [ 50.058162][ T7257] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 50.063695][ T7257] __tsan_read8+0x2c/0x30 [ 50.068004][ T7257] tcp_recvmsg+0x470/0x1a30 [ 50.072491][ T7257] inet_recvmsg+0xbb/0x250 [ 50.076884][ T7257] ? __tsan_read8+0x2c/0x30 [ 50.081372][ T7257] ? inet_sendpage+0x100/0x100 [ 50.086127][ T7257] sock_recvmsg+0x92/0xb0 [ 50.090434][ T7257] sock_read_iter+0x15f/0x1e0 [ 50.095098][ T7257] new_sync_read+0x389/0x4f0 [ 50.099670][ T7257] __vfs_read+0xb1/0xc0 [ 50.103802][ T7257] vfs_read+0x143/0x2c0 [ 50.107950][ T7257] ksys_read+0xd5/0x1b0 [ 50.112088][ T7257] __x64_sys_read+0x4c/0x60 [ 50.116572][ T7257] do_syscall_64+0xcc/0x370 [ 50.121052][ T7257] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 50.126934][ T7257] RIP: 0033:0x47c530 [ 50.130808][ T7257] 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 [ 50.150386][ T7257] RSP: 002b:000000c4202cd810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 50.158779][ T7257] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 50.166731][ T7257] RDX: 0000000000001000 RSI: 000000c4203ce000 RDI: 0000000000000003 [ 50.174681][ T7257] RBP: 000000c4202cd868 R08: 0000000000000000 R09: 0000000000000000 [ 50.182634][ T7257] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000200 [ 50.190585][ T7257] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 50.199973][ T7257] Kernel Offset: disabled [ 50.204296][ T7257] Rebooting in 86400 seconds..