Description of problem:
Service rh-varnish5-varnish can be started, but when simple page from httpd server is requested, varnish crashes and client get empty reply.

Version-Release number of selected component (if applicable):
rh-varnish5-varnish-5.2.1-1.el7

How reproducible:
always

Steps to Reproduce:
1. configure httpd to listen on 8080
2. create file in httpd rootdir
3. start httpd and rh-varnish5-varnish
4. request page through varnish: curl -v http://127.0.0.1:6081/hello.html
5. check journal for segfault

Actual results:
segfault, empty reply

Expected results:
page downloaded


Additional info:
log from journal:

led 19 05:40:34 qeos-35.lab.eng.rdu2.redhat.com abrt-hook-ccpp[27047]: Can't open 'core.26710' at '/var/opt/rh/rh-varnish5/lib/rh-varnish5-varnish/qeos-35.lab.eng.rdu2.redhat.com': Permission denied
led 19 05:40:34 qeos-35.lab.eng.rdu2.redhat.com abrt-hook-ccpp[27047]: Process 26710 (varnishd) of user 997 killed by SIGABRT - dumping core
led 19 05:40:34 qeos-35.lab.eng.rdu2.redhat.com abrt-hook-ccpp[27047]: Failed to create core_backtrace: waitpid failed: No child processes
led 19 05:40:34 qeos-35.lab.eng.rdu2.redhat.com varnishd[26700]: Child (26710) died signal=6 (core dumped)
led 19 05:40:34 qeos-35.lab.eng.rdu2.redhat.com varnishd[26700]: Child (26710) Panic at: Fri, 19 Jan 2018 10:40:34 GMT
    Wrong turn at mgt/mgt_child.c:287:
    Signal 11 (Segmentation fault) received at 0x7f0b6a83a480 si_code 2
    version = varnish-5.2.1 revision 67e562482, vrt api = 6.1
    ident = Linux,3.10.0-829.el7.x86_64,x86_64,-junix,-smalloc,-smalloc,-hcritbit,epoll
    now = 3704.397120 (mono), 1516358434.382164 (real)
    Backtrace:
      0x55c134937b14: /opt/rh/rh-varnish5/root/usr/sbin/varnishd(+0x4bb14) [0x55c134937b14]
      0x55c134983825: /opt/rh/rh-varnish5/root/usr/sbin/varnishd(VAS_Fail+0x45) [0x55c134983825]
      0x55c134966ec7: /opt/rh/rh-varnish5/root/usr/sbin/varnishd(+0x7aec7) [0x55c134966ec7]
      0x7f0b7503d630: /lib64/libpthread.so.0(+0xf630) [0x7f0b7503d630]
      0x7f0b75b98622: /lib64/libpcre.so.1(+0x26622) [0x7f0b75b98622]
      0x7f0b75bb68b9: /lib64/libpcre.so.1(+0x448b9) [0x7f0b75bb68b9]
      0x7f0b75b9722f: /lib64/libpcre.so.1(pcre_exec+0xeef) [0x7f0b75b9722f]
      0x55c1349892f9: /opt/rh/rh-varnish5/root/usr/sbin/varnishd(VRE_exec+0x89) [0x55c1349892f9]
      0x55c13494c21c: /opt/rh/rh-varnish5/root/usr/sbin/varnishd(VRT_re_match+0x7c) [0x55c13494c21c]
      0x7f0b68e0ef6c: vcl_boot.1516358304.628094912/vgc.so(VGC_function_vcl_backend_response+0x11c) [0x7f0b68e0ef6c]
    thread = (cache-worker)
    thr.req = (nil) {
    },
    thr.busyobj = 0x7f0b66c09fe0 {
      ws = 0x7f0b66c0a060 {
        id = \"bo\",
        {s, f, r, e} = {0x7f0b66c0bf20, +688, (nil), +57496},
      },
      retries = 0, failed = 0, flags = {do_stream},
      http_conn = 0x7f0b66c0bfd8 {
        fd = 27 (@0x7f0b6bd587f4),
        doclose = NULL,
        ws = 0x7f0b66c0a060 {
          [Already dumped, see above]
        },
        {rxbuf_b, rxbuf_e} = {0x7f0b66c0c038, 0x7f0b66c0c0fe},
        {pipeline_b, pipeline_e} = {0x7f0b66c0c0fe, 0x7f0b66c0c1ce},
        content_length = 208,
        body_status = length,
        first_byte_timeout = 60.000000,
        between_bytes_timeout = 60.000000,
      },
      director_req = 0x7f0b748841f8 {
        vcl_name = default,
        type = backend {
          display_name = boot.default,
          ipv4 = 127.0.0.1,
          port = 8080,
          hosthdr = 127.0.0.1,
          health = healthy,
          admin_health = probe, changed = 1516358304.901029,
          n_conn = 1,
        },
      },
      director_resp = director_req,
      http[bereq] = 0x7f0b66c0a630 {
        ws = 0x7f0b66c0a060 {
          [Already dumped, see above]
        },
        hdrs {
          \"GET\",
          \"/hello.html\",
          \"HTTP/1.1\",
          \"User-Agent: curl/7.29.0\",
          \"Host: 127.0.0.1:6081\",
          \"Accept: */*\",
          \"X-Forwarded-For: 127.0.0.1\",
          \"Accept-Encoding: gzip\",
          \"X-Varnish: 32771\",
        },
      },
      http[beresp] = 0x7f0b66c0aaa8 {
        ws = 0x7f0b66c0a060 {
          [Already dumped, see above]
        },
        hdrs {
          \"HTTP/1.1\",
          \"404\",
          \"Not Found\",
          \"Date: Fri, 19 Jan 2018 10:40:34 GMT\",
          \"Server: Apache/2.4.6 (Red Hat Enterprise Linux) OpenSSL/1.0.2k-fips\",
          \"Content-Length: 208\",
          \"Content-Type: text/html; charset=iso-8859-1\",
        },
      },
      objcore[fetch] = 0x7f0b66c79d00 {
        refcnt = 2,
        flags = {busy},
        exp_flags = {},
        boc = 0x7f0b66c7db00 {
          refcnt = 2,
          state = req_done,
          vary = (nil),
          stevedore_priv = (nil),
        },
        exp = {1516358434.382109, 120.000000, 10.000000, 0.000000},
        objhead = 0x7f0b6bd58780,
        stevedore = (nil),
      },
      vcl = {
        name = \"boot\",
        busy = 3,
        discard = 0,
        state = auto,
        temp = warm,
        conf = {
          srcname = {
            \"/etc/opt/rh/rh-varnish5/varnish/default.vcl\",
            \"Builtin\",
          },
        },
      },
      vmods = {
      },
    },