[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 34.397249][ T25] audit: type=1800 audit(1572773204.750:25): pid=7009 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 34.435917][ T25] audit: type=1800 audit(1572773204.750:26): pid=7009 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 34.484304][ T25] audit: type=1800 audit(1572773204.750:27): pid=7009 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 '10.128.0.179' (ECDSA) to the list of known hosts. 2019/11/03 09:26:54 fuzzer started 2019/11/03 09:26:55 dialing manager at 10.128.0.105:43165 2019/11/03 09:26:55 syscalls: 2554 2019/11/03 09:26:55 code coverage: enabled 2019/11/03 09:26:55 comparison tracing: enabled 2019/11/03 09:26:55 extra coverage: extra coverage is not supported by the kernel 2019/11/03 09:26:55 setuid sandbox: enabled 2019/11/03 09:26:55 namespace sandbox: enabled 2019/11/03 09:26:55 Android sandbox: /sys/fs/selinux/policy does not exist 2019/11/03 09:26:55 fault injection: enabled 2019/11/03 09:26:55 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/11/03 09:26:55 net packet injection: enabled 2019/11/03 09:26:55 net device setup: enabled 2019/11/03 09:26:55 concurrency sanitizer: enabled 2019/11/03 09:26:57 adding functions to KCSAN blacklist: 'task_dump_owner' '__tcp_select_window' 'tcp_add_backlog' 'tomoyo_supervisor' 'tick_sched_do_timer' '__hrtimer_run_queues' syzkaller login: [ 47.225081][ T7171] ================================================================== [ 47.233215][ T7171] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 47.239774][ T7171] [ 47.242088][ T7171] write to 0xffff888126b88e78 of 4 bytes by interrupt on cpu 1: [ 47.249742][ T7171] tcp_queue_rcv+0xe9/0x380 [ 47.254223][ T7171] tcp_rcv_established+0xbf1/0xf50 [ 47.259365][ T7171] tcp_v4_do_rcv+0x381/0x4e0 [ 47.263932][ T7171] tcp_v4_rcv+0x19dc/0x1bb0 [ 47.268412][ T7171] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.273763][ T7171] ip_local_deliver_finish+0x110/0x140 [ 47.279224][ T7171] ip_local_deliver+0x133/0x210 [ 47.284053][ T7171] ip_rcv_finish+0x121/0x160 [ 47.288619][ T7171] ip_rcv+0x18f/0x1a0 [ 47.292582][ T7171] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.298281][ T7171] __netif_receive_skb+0x37/0xf0 [ 47.303196][ T7171] netif_receive_skb_internal+0x59/0x190 [ 47.308824][ T7171] napi_gro_receive+0x28f/0x330 [ 47.313662][ T7171] receive_buf+0x284/0x30b0 [ 47.318134][ T7171] [ 47.320445][ T7171] read to 0xffff888126b88e78 of 4 bytes by task 7171 on cpu 0: [ 47.327971][ T7171] tcp_poll+0x204/0x6b0 [ 47.332106][ T7171] sock_poll+0xed/0x250 [ 47.336262][ T7171] ep_item_poll.isra.0+0x90/0x190 [ 47.341266][ T7171] ep_send_events_proc+0x113/0x590 [ 47.346355][ T7171] ep_scan_ready_list.constprop.0+0x189/0x500 [ 47.352401][ T7171] ep_poll+0xe3/0x900 [ 47.356363][ T7171] do_epoll_wait+0x162/0x180 [ 47.360933][ T7171] __x64_sys_epoll_pwait+0xcd/0x180 [ 47.366110][ T7171] do_syscall_64+0xcc/0x370 [ 47.370597][ T7171] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.376560][ T7171] [ 47.378866][ T7171] Reported by Kernel Concurrency Sanitizer on: [ 47.385014][ T7171] CPU: 0 PID: 7171 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.392460][ T7171] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.402510][ T7171] ================================================================== [ 47.410549][ T7171] Kernel panic - not syncing: panic_on_warn set ... [ 47.417116][ T7171] CPU: 0 PID: 7171 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.424542][ T7171] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.434573][ T7171] Call Trace: [ 47.437849][ T7171] dump_stack+0xf5/0x159 [ 47.442069][ T7171] panic+0x210/0x640 [ 47.445947][ T7171] ? do_syscall_64+0xcc/0x370 [ 47.450612][ T7171] ? vprintk_func+0x8d/0x140 [ 47.455185][ T7171] kcsan_report.cold+0xc/0x10 [ 47.459884][ T7171] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.465410][ T7171] __tsan_read4+0x2c/0x30 [ 47.469722][ T7171] tcp_poll+0x204/0x6b0 [ 47.473865][ T7171] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 47.479320][ T7171] sock_poll+0xed/0x250 [ 47.483473][ T7171] ? sock_read_iter+0x1e0/0x1e0 [ 47.488319][ T7171] ep_item_poll.isra.0+0x90/0x190 [ 47.493324][ T7171] ep_send_events_proc+0x113/0x590 [ 47.498416][ T7171] ? __schedule+0x319/0x640 [ 47.502898][ T7171] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.508519][ T7171] ep_scan_ready_list.constprop.0+0x189/0x500 [ 47.514566][ T7171] ? ep_loop_check_proc+0x2f0/0x2f0 [ 47.519759][ T7171] ep_poll+0xe3/0x900 [ 47.523723][ T7171] ? wake_up_q+0x70/0x70 [ 47.527947][ T7171] do_epoll_wait+0x162/0x180 [ 47.532532][ T7171] __x64_sys_epoll_pwait+0xcd/0x180 [ 47.537712][ T7171] do_syscall_64+0xcc/0x370 [ 47.542195][ T7171] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.548071][ T7171] RIP: 0033:0x45b300 [ 47.552043][ T7171] 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 [ 47.571640][ T7171] RSP: 002b:000000c4202ed860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 47.580030][ T7171] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 47.587982][ T7171] RDX: 0000000000000080 RSI: 000000c4202ed8a0 RDI: 0000000000000004 [ 47.595947][ T7171] RBP: 000000c4202edea0 R08: 0000000000000000 R09: 0000000000000000 [ 47.603897][ T7171] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000080 [ 47.611845][ T7171] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 47.621369][ T7171] Kernel Offset: disabled [ 47.627190][ T7171] Rebooting in 86400 seconds..