[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 42.382446][ T25] audit: type=1800 audit(1571738830.730:25): pid=7076 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2447 res=0 [ 42.426443][ T25] audit: type=1800 audit(1571738830.730:26): pid=7076 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2490 res=0 [ 42.463952][ T25] audit: type=1800 audit(1571738830.730:27): pid=7076 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 '10.128.0.249' (ECDSA) to the list of known hosts. 2019/10/22 10:07:19 fuzzer started 2019/10/22 10:07:20 dialing manager at 10.128.0.105:37053 2019/10/22 10:07:20 syscalls: 2524 2019/10/22 10:07:20 code coverage: enabled 2019/10/22 10:07:20 comparison tracing: enabled 2019/10/22 10:07:20 extra coverage: extra coverage is not supported by the kernel 2019/10/22 10:07:20 setuid sandbox: enabled 2019/10/22 10:07:20 namespace sandbox: enabled 2019/10/22 10:07:20 Android sandbox: /sys/fs/selinux/policy does not exist 2019/10/22 10:07:20 fault injection: enabled 2019/10/22 10:07:20 leak checking: CONFIG_DEBUG_KMEMLEAK is not enabled 2019/10/22 10:07:20 net packet injection: enabled 2019/10/22 10:07:20 net device setup: enabled 2019/10/22 10:07:20 concurrency sanitizer: enabled syzkaller login: [ 52.652685][ T7241] ================================================================== [ 52.660968][ T7241] BUG: KCSAN: data-race in tcp_poll / tcp_queue_rcv [ 52.667547][ T7241] [ 52.669870][ T7241] write to 0xffff88811ff1aeb8 of 4 bytes by interrupt on cpu 1: [ 52.677681][ T7241] tcp_queue_rcv+0xe9/0x380 [ 52.682258][ T7241] tcp_rcv_established+0xbf1/0xf50 [ 52.687362][ T7241] tcp_v4_do_rcv+0x381/0x4e0 [ 52.691937][ T7241] tcp_v4_rcv+0x19dc/0x1bb0 [ 52.696422][ T7241] ip_protocol_deliver_rcu+0x4d/0x420 [ 52.701777][ T7241] ip_local_deliver_finish+0x110/0x140 [ 52.707219][ T7241] ip_local_deliver+0x133/0x210 [ 52.712049][ T7241] ip_rcv_finish+0x121/0x160 [ 52.716619][ T7241] ip_rcv+0x18f/0x1a0 [ 52.720584][ T7241] __netif_receive_skb_one_core+0xa7/0xe0 [ 52.726342][ T7241] __netif_receive_skb+0x37/0xf0 [ 52.731264][ T7241] netif_receive_skb_internal+0x59/0x190 [ 52.736878][ T7241] napi_gro_receive+0x28f/0x330 [ 52.741713][ T7241] receive_buf+0x284/0x30b0 [ 52.746192][ T7241] [ 52.748507][ T7241] read to 0xffff88811ff1aeb8 of 4 bytes by task 7241 on cpu 0: [ 52.756034][ T7241] tcp_poll+0x204/0x6b0 [ 52.760174][ T7241] sock_poll+0xed/0x250 [ 52.764318][ T7241] ep_item_poll.isra.0+0x90/0x190 [ 52.769415][ T7241] ep_send_events_proc+0x113/0x590 [ 52.774579][ T7241] ep_scan_ready_list.constprop.0+0x189/0x500 [ 52.780630][ T7241] ep_poll+0xe3/0x900 [ 52.784681][ T7241] do_epoll_wait+0x162/0x180 [ 52.789255][ T7241] __x64_sys_epoll_pwait+0xcd/0x180 [ 52.794437][ T7241] do_syscall_64+0xcc/0x370 [ 52.798921][ T7241] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.804792][ T7241] [ 52.807159][ T7241] Reported by Kernel Concurrency Sanitizer on: [ 52.813306][ T7241] CPU: 0 PID: 7241 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.820749][ T7241] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.831036][ T7241] ================================================================== [ 52.839096][ T7241] Kernel panic - not syncing: panic_on_warn set ... [ 52.845679][ T7241] CPU: 0 PID: 7241 Comm: syz-fuzzer Not tainted 5.4.0-rc3+ #0 [ 52.853246][ T7241] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.863351][ T7241] Call Trace: [ 52.866637][ T7241] dump_stack+0xf5/0x159 [ 52.870884][ T7241] panic+0x210/0x640 [ 52.874807][ T7241] ? do_syscall_64+0xcc/0x370 [ 52.879470][ T7241] ? vprintk_func+0x8d/0x140 [ 52.884113][ T7241] kcsan_report.cold+0xc/0x10 [ 52.888778][ T7241] __kcsan_setup_watchpoint+0x32e/0x4a0 [ 52.894312][ T7241] __tsan_read4+0x2c/0x30 [ 52.898629][ T7241] tcp_poll+0x204/0x6b0 [ 52.902774][ T7241] ? tcp_alloc_md5sig_pool+0x320/0x320 [ 52.908218][ T7241] sock_poll+0xed/0x250 [ 52.912450][ T7241] ? sock_read_iter+0x1e0/0x1e0 [ 52.917288][ T7241] ep_item_poll.isra.0+0x90/0x190 [ 52.922430][ T7241] ep_send_events_proc+0x113/0x590 [ 52.927529][ T7241] ? __schedule+0x319/0x640 [ 52.932021][ T7241] ? __kcsan_setup_watchpoint+0x6b/0x4a0 [ 52.937642][ T7241] ep_scan_ready_list.constprop.0+0x189/0x500 [ 52.943694][ T7241] ? ep_loop_check_proc+0x2f0/0x2f0 [ 52.949020][ T7241] ep_poll+0xe3/0x900 [ 52.952992][ T7241] ? wake_up_q+0x70/0x70 [ 52.957223][ T7241] do_epoll_wait+0x162/0x180 [ 52.961805][ T7241] __x64_sys_epoll_pwait+0xcd/0x180 [ 52.967033][ T7241] do_syscall_64+0xcc/0x370 [ 52.971612][ T7241] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 52.977486][ T7241] RIP: 0033:0x45b300 [ 52.981371][ T7241] 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 [ 53.000958][ T7241] RSP: 002b:000000c4202d7860 EFLAGS: 00000246 ORIG_RAX: 0000000000000119 [ 53.009384][ T7241] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 000000000045b300 [ 53.017482][ T7241] RDX: 0000000000000080 RSI: 000000c4202d78a0 RDI: 0000000000000004 [ 53.025453][ T7241] RBP: 000000c4202d7ea0 R08: 0000000000000000 R09: 0000000000000000 [ 53.033476][ T7241] R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000000004 [ 53.041431][ T7241] R13: ffffffffffffffff R14: 0000000000000004 R15: ffffffffffffffff [ 53.050906][ T7241] Kernel Offset: disabled [ 53.055239][ T7241] Rebooting in 86400 seconds..