[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.161173][ T25] audit: type=1800 audit(1571692697.966:25): pid=7102 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.188646][ T25] audit: type=1800 audit(1571692697.976:26): pid=7102 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.215502][ T25] audit: type=1800 audit(1571692697.976:27): pid=7102 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 '10.128.0.231' (ECDSA) to the list of known hosts. 2019/10/21 21:18:29 fuzzer started 2019/10/21 21:18:31 dialing manager at 10.128.0.105:39747 2019/10/21 21:18:31 syscalls: 2524 2019/10/21 21:18:31 code coverage: enabled 2019/10/21 21:18:31 comparison tracing: enabled 2019/10/21 21:18:31 extra coverage: extra coverage is not supported by the kernel 2019/10/21 21:18:31 setuid sandbox: enabled 2019/10/21 21:18:31 namespace sandbox: enabled 2019/10/21 21:18:31 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/21 21:18:31 fault injection: enabled 2019/10/21 21:18:31 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/21 21:18:31 net packet injection: enabled 2019/10/21 21:18:31 net device setup: enabled 2019/10/21 21:18:31 concurrency sanitizer: enabled syzkaller login: [ 47.953882][ T7259] ================================================================== [ 47.962014][ T7259] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 47.968594][ T7259] [ 47.970922][ T7259] write to 0xffff888122edd778 of 4 bytes by interrupt on cpu 0: [ 47.978561][ T7259] tcp_queue_rcv+0x180/0x380 [ 47.983127][ T7259] tcp_data_queue+0x7bb/0x20b0 [ 47.987868][ T7259] tcp_rcv_established+0x517/0xf50 [ 47.992959][ T7259] tcp_v4_do_rcv+0x381/0x4e0 [ 47.997549][ T7259] tcp_v4_rcv+0x19dc/0x1bb0 [ 48.002028][ T7259] ip_protocol_deliver_rcu+0x4d/0x420 [ 48.007383][ T7259] ip_local_deliver_finish+0x110/0x140 [ 48.012826][ T7259] ip_local_deliver+0x133/0x210 [ 48.017667][ T7259] ip_rcv_finish+0x121/0x160 [ 48.022256][ T7259] ip_rcv+0x18f/0x1a0 [ 48.026236][ T7259] __netif_receive_skb_one_core+0xa7/0xe0 [ 48.031941][ T7259] __netif_receive_skb+0x37/0xf0 [ 48.036867][ T7259] netif_receive_skb_internal+0x59/0x190 [ 48.042488][ T7259] napi_gro_receive+0x28f/0x330 [ 48.047306][ T7259] [ 48.049627][ T7259] read to 0xffff888122edd778 of 4 bytes by task 7259 on cpu 1: [ 48.057143][ T7259] tcp_poll+0x204/0x6b0 [ 48.061276][ T7259] sock_poll+0xed/0x250 [ 48.065408][ T7259] ep_item_poll.isra.0+0x90/0x190 [ 48.070409][ T7259] ep_send_events_proc+0x113/0x590 [ 48.075498][ T7259] ep_scan_ready_list.constprop.0+0x189/0x500 [ 48.081547][ T7259] ep_poll+0xe3/0x900 [ 48.085511][ T7259] do_epoll_wait+0x162/0x180 [ 48.090076][ T7259] __x64_sys_epoll_pwait+0xcd/0x180 [ 48.095255][ T7259] do_syscall_64+0xcc/0x370 [ 48.099737][ T7259] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.105610][ T7259] [ 48.107910][ T7259] Reported by Kernel Concurrency Sanitizer on: [ 48.114044][ T7259] CPU: 1 PID: 7259 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.121470][ T7259] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.131501][ T7259] ================================================================== [ 48.139552][ T7259] Kernel panic - not syncing: panic_on_warn set ... [ 48.146126][ T7259] CPU: 1 PID: 7259 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 48.153553][ T7259] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 48.163598][ T7259] Call Trace: [ 48.166870][ T7259] dump_stack+0xf5/0x159 [ 48.171105][ T7259] panic+0x210/0x640 [ 48.174997][ T7259] ? do_syscall_64+0xcc/0x370 [ 48.179654][ T7259] ? vprintk_func+0x8d/0x140 [ 48.184225][ T7259] kcsan_report.cold+0xc/0x10 [ 48.188881][ T7259] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 48.194407][ T7259] ? tcp_recvmsg+0x65b/0x1a30 [ 48.199097][ T7259] __tsan_read4+0x2c/0x30 [ 48.203420][ T7259] tcp_poll+0x204/0x6b0 [ 48.207557][ T7259] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 48.212994][ T7259] sock_poll+0xed/0x250 [ 48.217133][ T7259] ? sock_read_iter+0x1e0/0x1e0 [ 48.221960][ T7259] ep_item_poll.isra.0+0x90/0x190 [ 48.226963][ T7259] ep_send_events_proc+0x113/0x590 [ 48.232058][ T7259] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.237676][ T7259] ep_scan_ready_list.constprop.0+0x189/0x500 [ 48.243773][ T7259] ? ep_loop_check_proc+0x2f0/0x2f0 [ 48.248952][ T7259] ep_poll+0xe3/0x900 [ 48.252912][ T7259] ? __fget+0xb8/0x1d0 [ 48.256974][ T7259] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.262580][ T7259] ? __fget_light+0xaf/0x190 [ 48.267163][ T7259] do_epoll_wait+0x162/0x180 [ 48.271735][ T7259] __x64_sys_epoll_pwait+0xcd/0x180 [ 48.277009][ T7259] do_syscall_64+0xcc/0x370 [ 48.281498][ T7259] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.287365][ T7259] RIP: 0033:0x45b300 [ 48.291238][ T7259] Code: 0f 05 89 44 24 20 c3 cc cc cc 8b 7c 24 08 48 8b 74 24 10 8b 54 24 18 44 8b 54 24 1c 49 c7 c0 00 00 00 00 b8 19 01 00 00 0f 05 <89> 44 24 20 c3 cc cc cc cc cc cc cc cc cc cc cc 8b 7c 24 08 48 c7 [ 48.310828][ T7259] RSP: 002b:000000c420147860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 48.319232][ T7259] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045b300 [ 48.327196][ T7259] RDX: 0000000000000080 RSI: 000000c4201478a0 RDI: 0000000000000004 [ 48.335243][ T7259] RBP: 000000c420147ea0 R08: 0000000000000000 R09: 0000000000000000 [ 48.343250][ T7259] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000010 [ 48.351204][ T7259] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.360455][ T7259] Kernel Offset: disabled [ 48.364781][ T7259] Rebooting in 86400 seconds..