[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 36.648415][ T26] audit: type=1800 audit(1571774171.426:25): pid=7057 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 36.702188][ T26] audit: type=1800 audit(1571774171.426:26): pid=7057 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 36.722638][ T26] audit: type=1800 audit(1571774171.426:27): pid=7057 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 '10.128.0.182' (ECDSA) to the list of known hosts. 2019/10/22 19:56:19 fuzzer started 2019/10/22 19:56:21 dialing manager at 10.128.0.105:33369 2019/10/22 19:56:21 syscalls: 2524 2019/10/22 19:56:21 code coverage: enabled 2019/10/22 19:56:21 comparison tracing: enabled 2019/10/22 19:56:21 extra coverage: extra coverage is not supported by the kernel 2019/10/22 19:56:21 setuid sandbox: enabled 2019/10/22 19:56:21 namespace sandbox: enabled 2019/10/22 19:56:21 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 19:56:21 fault injection: enabled 2019/10/22 19:56:21 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 19:56:21 net packet injection: enabled 2019/10/22 19:56:21 net device setup: enabled 2019/10/22 19:56:21 concurrency sanitizer: enabled syzkaller login: [ 47.754408][ T7222] ================================================================== [ 47.762579][ T7222] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 47.769154][ T7222] [ 47.771465][ T7222] write to 0xffff888124d0b7b8 of 4 bytes by interrupt on cpu 0: [ 47.779073][ T7222] tcp_queue_rcv+0xe9/0x380 [ 47.783553][ T7222] tcp_rcv_established+0xbf1/0xf50 [ 47.788742][ T7222] tcp_v4_do_rcv+0x381/0x4e0 [ 47.793327][ T7222] tcp_v4_rcv+0x19dc/0x1bb0 [ 47.797816][ T7222] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.803167][ T7222] ip_local_deliver_finish+0x110/0x140 [ 47.808603][ T7222] ip_local_deliver+0x133/0x210 [ 47.813431][ T7222] ip_rcv_finish+0x121/0x160 [ 47.817997][ T7222] ip_rcv+0x18f/0x1a0 [ 47.821972][ T7222] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.827762][ T7222] __netif_receive_skb+0x37/0xf0 [ 47.832766][ T7222] netif_receive_skb_internal+0x59/0x190 [ 47.838425][ T7222] napi_gro_receive+0x28f/0x330 [ 47.843258][ T7222] receive_buf+0x284/0x30b0 [ 47.847738][ T7222] [ 47.850054][ T7222] read to 0xffff888124d0b7b8 of 4 bytes by task 7222 on cpu 1: [ 47.857583][ T7222] tcp_poll+0x204/0x6b0 [ 47.861730][ T7222] sock_poll+0xed/0x250 [ 47.865871][ T7222] ep_item_poll.isra.0+0x90/0x190 [ 47.870895][ T7222] ep_send_events_proc+0x113/0x590 [ 47.876091][ T7222] ep_scan_ready_list.constprop.0+0x189/0x500 [ 47.882144][ T7222] ep_poll+0xe3/0x900 [ 47.886103][ T7222] do_epoll_wait+0x162/0x180 [ 47.890760][ T7222] __x64_sys_epoll_pwait+0xcd/0x180 [ 47.896207][ T7222] do_syscall_64+0xcc/0x370 [ 47.900862][ T7222] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.906820][ T7222] [ 47.909132][ T7222] Reported by Kernel Concurrency Sanitizer on: [ 47.915280][ T7222] CPU: 1 PID: 7222 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.922707][ T7222] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.932853][ T7222] ================================================================== [ 47.940905][ T7222] Kernel panic - not syncing: panic_on_warn set ... [ 47.947473][ T7222] CPU: 1 PID: 7222 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.954937][ T7222] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.965318][ T7222] Call Trace: [ 47.968654][ T7222] dump_stack+0xf5/0x159 [ 47.973032][ T7222] panic+0x210/0x640 [ 47.976937][ T7222] ? do_syscall_64+0xcc/0x370 [ 47.981621][ T7222] ? vprintk_func+0x8d/0x140 [ 47.986288][ T7222] kcsan_report.cold+0xc/0x10 [ 47.990970][ T7222] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.996586][ T7222] ? tcp_recvmsg+0x65b/0x1a30 [ 48.001243][ T7222] __tsan_read4+0x2c/0x30 [ 48.005572][ T7222] tcp_poll+0x204/0x6b0 [ 48.009711][ T7222] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 48.015158][ T7222] sock_poll+0xed/0x250 [ 48.019314][ T7222] ? sock_read_iter+0x1e0/0x1e0 [ 48.024432][ T7222] ep_item_poll.isra.0+0x90/0x190 [ 48.029449][ T7222] ep_send_events_proc+0x113/0x590 [ 48.034544][ T7222] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.040169][ T7222] ep_scan_ready_list.constprop.0+0x189/0x500 [ 48.046310][ T7222] ? ep_loop_check_proc+0x2f0/0x2f0 [ 48.051503][ T7222] ep_poll+0xe3/0x900 [ 48.055477][ T7222] ? __fget+0xb8/0x1d0 [ 48.060222][ T7222] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 48.065906][ T7222] ? __fget_light+0xaf/0x190 [ 48.070676][ T7222] do_epoll_wait+0x162/0x180 [ 48.075249][ T7222] __x64_sys_epoll_pwait+0xcd/0x180 [ 48.080537][ T7222] do_syscall_64+0xcc/0x370 [ 48.085109][ T7222] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 48.090980][ T7222] RIP: 0033:0x45b300 [ 48.094859][ T7222] 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 [ 48.114615][ T7222] RSP: 002b:000000c4203b5860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 48.123017][ T7222] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 48.131055][ T7222] RDX: 0000000000000080 RSI: 000000c4203b58a0 RDI: 0000000000000004 [ 48.139019][ T7222] RBP: 000000c4203b5ea0 R08: 0000000000000000 R09: 0000000000000000 [ 48.147057][ T7222] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000004 [ 48.155007][ T7222] R13: ffffffffffffffff R14: 0000000000000002 R15: ffffffffffffffff [ 48.164493][ T7222] Kernel Offset: disabled [ 48.168850][ T7222] Rebooting in 86400 seconds..