[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.968445][ T25] audit: type=1800 audit(1572632981.379:25): pid=7015 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.995758][ T25] audit: type=1800 audit(1572632981.389:26): pid=7015 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.022780][ T25] audit: type=1800 audit(1572632981.389:27): pid=7015 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 '10.128.15.204' (ECDSA) to the list of known hosts. 2019/11/01 18:29:53 fuzzer started 2019/11/01 18:29:55 dialing manager at 10.128.0.105:41349 2019/11/01 18:29:55 syscalls: 2540 2019/11/01 18:29:55 code coverage: enabled 2019/11/01 18:29:55 comparison tracing: enabled 2019/11/01 18:29:55 extra coverage: extra coverage is not supported by the kernel 2019/11/01 18:29:55 setuid sandbox: enabled 2019/11/01 18:29:55 namespace sandbox: enabled 2019/11/01 18:29:55 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/01 18:29:55 fault injection: enabled 2019/11/01 18:29:55 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/01 18:29:55 net packet injection: enabled 2019/11/01 18:29:55 net device setup: enabled 2019/11/01 18:29:55 concurrency sanitizer: enabled 2019/11/01 18:29:55 adding functions to KCSAN blacklist: 'pid_update_inode' 'tomoyo_supervisor' '__hrtimer_run_queues' 'tick_do_update_jiffies64' 'ep_poll' syzkaller login: [ 49.232214][ T7165] ================================================================== [ 49.240346][ T7165] BUG: KCSAN: data-race in tcp_add_backlog / tcp_recvmsg [ 49.247344][ T7165] [ 49.249653][ T7165] write to 0xffff888126a0a9f8 of 8 bytes by interrupt on cpu 1: [ 49.257262][ T7165] tcp_add_backlog+0x45a/0xcc0 [ 49.262005][ T7165] tcp_v4_rcv+0x1a60/0x1bb0 [ 49.266485][ T7165] ip_protocol_deliver_rcu+0x4d/0x420 [ 49.271832][ T7165] ip_local_deliver_finish+0x110/0x140 [ 49.277263][ T7165] ip_local_deliver+0x133/0x210 [ 49.282088][ T7165] ip_rcv_finish+0x121/0x160 [ 49.286686][ T7165] ip_rcv+0x18f/0x1a0 [ 49.290647][ T7165] __netif_receive_skb_one_core+0xa7/0xe0 [ 49.296345][ T7165] __netif_receive_skb+0x37/0xf0 [ 49.301259][ T7165] netif_receive_skb_internal+0x59/0x190 [ 49.306865][ T7165] napi_gro_receive+0x28f/0x330 [ 49.311702][ T7165] receive_buf+0x284/0x30b0 [ 49.316184][ T7165] virtnet_poll+0x436/0x7d0 [ 49.320664][ T7165] net_rx_action+0x3ae/0xa90 [ 49.325221][ T7165] [ 49.327526][ T7165] read to 0xffff888126a0a9f8 of 8 bytes by task 7165 on cpu 0: [ 49.335055][ T7165] tcp_recvmsg+0x470/0x1a30 [ 49.339538][ T7165] inet_recvmsg+0xbb/0x250 [ 49.343934][ T7165] sock_recvmsg+0x92/0xb0 [ 49.348250][ T7165] sock_read_iter+0x15f/0x1e0 [ 49.352905][ T7165] new_sync_read+0x389/0x4f0 [ 49.357480][ T7165] __vfs_read+0xb1/0xc0 [ 49.361614][ T7165] vfs_read+0x143/0x2c0 [ 49.365750][ T7165] ksys_read+0xd5/0x1b0 [ 49.370838][ T7165] __x64_sys_read+0x4c/0x60 [ 49.375318][ T7165] do_syscall_64+0xcc/0x370 [ 49.379799][ T7165] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.385672][ T7165] [ 49.387977][ T7165] Reported by Kernel Concurrency Sanitizer on: [ 49.394108][ T7165] CPU: 0 PID: 7165 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.401537][ T7165] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.411577][ T7165] ================================================================== [ 49.419613][ T7165] Kernel panic - not syncing: panic_on_warn set ... [ 49.426203][ T7165] CPU: 0 PID: 7165 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 49.433640][ T7165] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 49.443667][ T7165] Call Trace: [ 49.446954][ T7165] dump_stack+0xf5/0x159 [ 49.451197][ T7165] panic+0x210/0x640 [ 49.455070][ T7165] ? __x64_sys_read+0x4c/0x60 [ 49.459726][ T7165] ? vprintk_func+0x8d/0x140 [ 49.464301][ T7165] kcsan_report.cold+0xc/0x10 [ 49.469022][ T7165] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 49.474569][ T7165] __tsan_read8+0x2c/0x30 [ 49.478891][ T7165] tcp_recvmsg+0x470/0x1a30 [ 49.483383][ T7165] inet_recvmsg+0xbb/0x250 [ 49.487776][ T7165] ? __tsan_read8+0x2c/0x30 [ 49.492255][ T7165] ? inet_sendpage+0x100/0x100 [ 49.497002][ T7165] sock_recvmsg+0x92/0xb0 [ 49.501310][ T7165] sock_read_iter+0x15f/0x1e0 [ 49.505970][ T7165] new_sync_read+0x389/0x4f0 [ 49.510542][ T7165] __vfs_read+0xb1/0xc0 [ 49.514712][ T7165] vfs_read+0x143/0x2c0 [ 49.518857][ T7165] ksys_read+0xd5/0x1b0 [ 49.523001][ T7165] __x64_sys_read+0x4c/0x60 [ 49.527492][ T7165] do_syscall_64+0xcc/0x370 [ 49.531973][ T7165] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 49.537849][ T7165] RIP: 0033:0x47c530 [ 49.541743][ T7165] 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 [ 49.561327][ T7165] RSP: 002b:000000c4202cd810 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 [ 49.569718][ T7165] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047c530 [ 49.577670][ T7165] RDX: 0000000000001000 RSI: 000000c420186000 RDI: 0000000000000003 [ 49.585642][ T7165] RBP: 000000c4202cd868 R08: 0000000000000000 R09: 0000000000000000 [ 49.593610][ T7165] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000040 [ 49.601824][ T7165] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 49.611009][ T7165] Kernel Offset: disabled [ 49.615330][ T7165] Rebooting in 86400 seconds..