[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 35.155150][ T25] audit: type=1800 audit(1571706251.951:25): pid=6995 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 35.196452][ T25] audit: type=1800 audit(1571706251.951:26): pid=6995 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 35.218480][ T25] audit: type=1800 audit(1571706251.961:27): pid=6995 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 '10.128.0.63' (ECDSA) to the list of known hosts. 2019/10/22 01:04:22 fuzzer started 2019/10/22 01:04:23 dialing manager at 10.128.0.105:37053 2019/10/22 01:04:23 syscalls: 2524 2019/10/22 01:04:23 code coverage: enabled 2019/10/22 01:04:23 comparison tracing: enabled 2019/10/22 01:04:23 extra coverage: extra coverage is not supported by the kernel 2019/10/22 01:04:23 setuid sandbox: enabled 2019/10/22 01:04:23 namespace sandbox: enabled 2019/10/22 01:04:23 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 01:04:23 fault injection: enabled 2019/10/22 01:04:23 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 01:04:23 net packet injection: enabled 2019/10/22 01:04:23 net device setup: enabled 2019/10/22 01:04:23 concurrency sanitizer: enabled syzkaller login: [ 47.257023][ T7157] ================================================================== [ 47.265167][ T7157] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 47.271781][ T7157] [ 47.274100][ T7157] write to 0xffff888123a537b8 of 4 bytes by interrupt on cpu 0: [ 47.281713][ T7157] tcp_queue_rcv+0xe9/0x380 [ 47.286217][ T7157] tcp_rcv_established+0xbf1/0xf50 [ 47.291319][ T7157] tcp_v4_do_rcv+0x381/0x4e0 [ 47.295888][ T7157] tcp_v4_rcv+0x19dc/0x1bb0 [ 47.300385][ T7157] ip_protocol_deliver_rcu+0x4d/0x420 [ 47.305732][ T7157] ip_local_deliver_finish+0x110/0x140 [ 47.311182][ T7157] ip_local_deliver+0x133/0x210 [ 47.316010][ T7157] ip_rcv_finish+0x121/0x160 [ 47.320590][ T7157] ip_rcv+0x18f/0x1a0 [ 47.324565][ T7157] __netif_receive_skb_one_core+0xa7/0xe0 [ 47.330261][ T7157] __netif_receive_skb+0x37/0xf0 [ 47.335263][ T7157] netif_receive_skb_internal+0x59/0x190 [ 47.340873][ T7157] napi_gro_receive+0x28f/0x330 [ 47.345712][ T7157] receive_buf+0x284/0x30b0 [ 47.350189][ T7157] [ 47.352498][ T7157] read to 0xffff888123a537b8 of 4 bytes by task 7157 on cpu 1: [ 47.360015][ T7157] tcp_poll+0x204/0x6b0 [ 47.364149][ T7157] sock_poll+0xed/0x250 [ 47.368311][ T7157] ep_item_poll.isra.0+0x90/0x190 [ 47.373318][ T7157] ep_send_events_proc+0x113/0x590 [ 47.378409][ T7157] ep_scan_ready_list.constprop.0+0x189/0x500 [ 47.384467][ T7157] ep_poll+0xe3/0x900 [ 47.388437][ T7157] do_epoll_wait+0x162/0x180 [ 47.393031][ T7157] __x64_sys_epoll_pwait+0xcd/0x180 [ 47.398223][ T7157] do_syscall_64+0xcc/0x370 [ 47.402702][ T7157] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.408562][ T7157] [ 47.410865][ T7157] Reported by Kernel Concurrency Sanitizer on: [ 47.416996][ T7157] CPU: 1 PID: 7157 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.424424][ T7157] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.434464][ T7157] ================================================================== [ 47.442527][ T7157] Kernel panic - not syncing: panic_on_warn set ... [ 47.449103][ T7157] CPU: 1 PID: 7157 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 47.456529][ T7157] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 47.466563][ T7157] Call Trace: [ 47.469835][ T7157] dump_stack+0xf5/0x159 [ 47.474058][ T7157] panic+0x210/0x640 [ 47.477933][ T7157] ? do_syscall_64+0xcc/0x370 [ 47.482585][ T7157] ? vprintk_func+0x8d/0x140 [ 47.487150][ T7157] kcsan_report.cold+0xc/0x10 [ 47.491805][ T7157] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 47.497331][ T7157] __tsan_read4+0x2c/0x30 [ 47.501639][ T7157] tcp_poll+0x204/0x6b0 [ 47.505774][ T7157] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 47.511212][ T7157] sock_poll+0xed/0x250 [ 47.515347][ T7157] ? sock_read_iter+0x1e0/0x1e0 [ 47.520180][ T7157] ep_item_poll.isra.0+0x90/0x190 [ 47.525188][ T7157] ep_send_events_proc+0x113/0x590 [ 47.530276][ T7157] ? __schedule+0x319/0x640 [ 47.534756][ T7157] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 47.540418][ T7157] ep_scan_ready_list.constprop.0+0x189/0x500 [ 47.546463][ T7157] ? ep_loop_check_proc+0x2f0/0x2f0 [ 47.551639][ T7157] ep_poll+0xe3/0x900 [ 47.555612][ T7157] ? wake_up_q+0x70/0x70 [ 47.559842][ T7157] do_epoll_wait+0x162/0x180 [ 47.564420][ T7157] __x64_sys_epoll_pwait+0xcd/0x180 [ 47.569597][ T7157] do_syscall_64+0xcc/0x370 [ 47.574077][ T7157] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 47.579943][ T7157] RIP: 0033:0x45b300 [ 47.583858][ T7157] 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 [ 47.603441][ T7157] RSP: 002b:000000c42014f860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 47.611827][ T7157] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 47.619774][ T7157] RDX: 0000000000000080 RSI: 000000c42014f8a0 RDI: 0000000000000004 [ 47.627726][ T7157] RBP: 000000c42014fea0 R08: 0000000000000000 R09: 0000000000000000 [ 47.635675][ T7157] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000080 [ 47.643633][ T7157] R13: ffffffffffffffff R14: 0000000000000008 R15: ffffffffffffffff [ 47.652772][ T7157] Kernel Offset: disabled [ 47.657102][ T7157] Rebooting in 86400 seconds..