[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.934826][ T23] audit: type=1800 audit(1571741691.971:25): pid=7092 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.971140][ T23] audit: type=1800 audit(1571741691.971:26): pid=7092 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.000623][ T23] audit: type=1800 audit(1571741691.971:27): pid=7092 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 '10.128.0.132' (ECDSA) to the list of known hosts. 2019/10/22 10:55:02 fuzzer started 2019/10/22 10:55:04 dialing manager at 10.128.0.105:37053 2019/10/22 10:55:04 syscalls: 2524 2019/10/22 10:55:04 code coverage: enabled 2019/10/22 10:55:04 comparison tracing: enabled 2019/10/22 10:55:04 extra coverage: extra coverage is not supported by the kernel 2019/10/22 10:55:04 setuid sandbox: enabled 2019/10/22 10:55:04 namespace sandbox: enabled 2019/10/22 10:55:04 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 10:55:04 fault injection: enabled 2019/10/22 10:55:04 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 10:55:04 net packet injection: enabled 2019/10/22 10:55:04 net device setup: enabled 2019/10/22 10:55:04 concurrency sanitizer: enabled syzkaller login: [ 47.903619][ T7246] ================================================================== [ 47.911752][ T7246] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 47.918752][ T7246] [ 47.921072][ T7246] write to 0xffff88812646b2f8 of 8 bytes by interrupt on cpu 1: [ 47.928688][ T7246] tcp_add_backlog+0x45a/0xcc0 [ 47.933462][ T7246] tcp_v4_rcv+0x1a60/0x1bb0 [ 47.937939][ T7246] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.943283][ T7246] ip_local_deliver_finish+0x110/0x140 [ 47.948717][ T7246] ip_local_deliver+0x133/0x210 [ 47.953540][ T7246] ip_rcv_finish+0x121/0x160 [ 47.958105][ T7246] ip_rcv+0x18f/0x1a0 [ 47.962062][ T7246] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.967754][ T7246] __netif_receive_skb+0x37/0xf0 [ 47.972667][ T7246] netif_receive_skb_internal+0x59/0x190 [ 47.978310][ T7246] napi_gro_receive+0x28f/0x330 [ 47.983133][ T7246] receive_buf+0x284/0x30b0 [ 47.987609][ T7246] virtnet_poll+0x436/0x7d0 [ 47.992084][ T7246] net_rx_action+0x3ae/0xa90 [ 47.996642][ T7246] [ 47.998960][ T7246] read to 0xffff88812646b2f8 of 8 bytes by task 7246 on cpu 0: [ 48.006474][ T7246] tcp_recvmsg+0x470/0x1a30 [ 48.010951][ T7246] inet_recvmsg+0xbb/0x250 [ 48.015340][ T7246] sock_recvmsg+0x92/0xb0 [ 48.019644][ T7246] sock_read_iter+0x15f/0x1e0 [ 48.024300][ T7246] new_sync_read+0x389/0x4f0 [ 48.028874][ T7246] __vfs_read+0xb1/0xc0 [ 48.033007][ T7246] vfs_read+0x143/0x2c0 [ 48.037134][ T7246] ksys_read+0xd5/0x1b0 [ 48.041265][ T7246] __x64_sys_read+0x4c/0x60 [ 48.045746][ T7246] do_syscall_64+0xcc/0x370 [ 48.050222][ T7246] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.056083][ T7246] [ 48.058387][ T7246] Reported by Kernel Concurrency Sanitizer on: [ 48.064513][ T7246] CPU: 0 PID: 7246 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.071949][ T7246] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.081976][ T7246] ================================================================== [ 48.090016][ T7246] Kernel panic - not syncing: panic_on_warn set ... [ 48.096595][ T7246] CPU: 0 PID: 7246 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.104028][ T7246] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.114078][ T7246] Call Trace: [ 48.117359][ T7246] dump_stack+0xf5/0x159 [ 48.121580][ T7246] panic+0x210/0x640 [ 48.125454][ T7246] ? __x64_sys_read+0x4c/0x60 [ 48.130110][ T7246] ? vprintk_func+0x8d/0x140 [ 48.134689][ T7246] kcsan_report.cold+0xc/0x10 [ 48.139356][ T7246] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.144882][ T7246] __tsan_read8+0x2c/0x30 [ 48.149194][ T7246] tcp_recvmsg+0x470/0x1a30 [ 48.153684][ T7246] inet_recvmsg+0xbb/0x250 [ 48.158089][ T7246] ? __tsan_read8+0x2c/0x30 [ 48.162578][ T7246] ? inet_sendpage+0x100/0x100 [ 48.167324][ T7246] sock_recvmsg+0x92/0xb0 [ 48.171678][ T7246] sock_read_iter+0x15f/0x1e0 [ 48.176381][ T7246] new_sync_read+0x389/0x4f0 [ 48.180953][ T7246] __vfs_read+0xb1/0xc0 [ 48.185089][ T7246] vfs_read+0x143/0x2c0 [ 48.189226][ T7246] ksys_read+0xd5/0x1b0 [ 48.193369][ T7246] __x64_sys_read+0x4c/0x60 [ 48.197870][ T7246] do_syscall_64+0xcc/0x370 [ 48.202387][ T7246] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.208251][ T7246] RIP: 0033:0x47c530 [ 48.212122][ T7246] 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 [ 48.231709][ T7246] RSP: 002b:000000c4203ab810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 48.240184][ T7246] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 48.248145][ T7246] RDX: 0000000000001000 RSI: 000000c42015a000 RDI: 0000000000000003 [ 48.256109][ T7246] RBP: 000000c4203ab868 R08: 0000000000000000 R09: 0000000000000000 [ 48.264059][ T7246] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 [ 48.272014][ T7246] R13: 000000c42007ec80 R14: 0000000000000002 R15: ffffffffffffffff [ 48.281214][ T7246] Kernel Offset: disabled [ 48.285533][ T7246] Rebooting in 86400 seconds..