general/7460: segmentation fault on starting

[Shotaro Kamio <ka...@vuni.ne.jp>]

>Number:         7460
>Category:       general
>Synopsis:       segmentation fault on starting
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Mon Mar 26 00:30:00 PST 2001
>Closed-Date:
>Last-Modified:
>Originator:     kamio@vuni.ne.jp
>Release:        1.3.19
>Organization:
apache
>Environment:
Linux i486 gcc RedHat 6.0
>Description:
I built from source and start by "apachectl start".
but httpd crashed "segmentation fault".
there is no error message. so I was confused.

I run gdb. then, I found a bug.
backtrace is below

% gdb httpd core
GNU gdb 4.17.0.11 with Linux support
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GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
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This GDB was configured as "i386-redhat-linux"...
Core was generated by `./httpd'.
Program terminated with signal 11, Segmentation fault.
Reading symbols from /lib/libm.so.6...done.
Reading symbols from /lib/libcrypt.so.1...done.
Reading symbols from /lib/libc.so.6...bt
done.
Reading symbols from /lib/ld-linux.so.2...done.
Reading symbols from /lib/libnss_files.so.2...done.
Reading symbols from /lib/libnss_nisplus.so.2...done.
Reading symbols from /lib/libnsl.so.1...done.
Reading symbols from /lib/libnss_nis.so.2...done.
Reading symbols from /lib/libnss_dns.so.2...done.
Reading symbols from /lib/libresolv.so.2...done.
#0  0x807f543 in ap_get_local_host (a=0x80c697c) at util.c:2051
2051                if (p->h_addr_list[0]) {
(gdb) bt
#0  0x807f543 in ap_get_local_host (a=0x80c697c) at util.c:2051
#1  0x807b6ea in ap_fini_vhost_config (p=0x80c697c, main_s=0x80c69a4) at http_vhost.c:548
#2  0x8068f72 in ap_read_config (p=0x80c697c, ptemp=0x80ca99c, 
    confname=0x80bf3c0 "conf/httpd.conf") at http_config.c:1595
#3  0x8073009 in main (argc=1, argv=0xbffffbe4) at http_main.c:4986
#4  0x40078cb3 in __libc_start_main (main=0x8072d7c <main>, argc=1, argv=0xbffffbe4, 
    init=0x8049b6c <_init>, fini=0x80a770c <_fini>, rtld_fini=0x4000a350 <_dl_fini>, 
    stack_end=0xbffffbdc) at ../sysdeps/generic/libc-start.c:78
(gdb) list
2046        {
2047            str[sizeof(str) - 1] = '\0';
2048            if ((!(p = gethostbyname(str))) 
2049                || (!(server_hostname = find_fqdn(a, p)))) {
2050                /* Recovery - return the default servername by IP: */
2051                if (p->h_addr_list[0]) {
2052                    ap_snprintf(str, sizeof(str), "%pA", p->h_addr_list[0]);
2053                    server_hostname = ap_pstrdup(a, str);
2054                    /* We will drop through to report the IP-named server */
2055                }
(gdb)  print p
$1 = (struct hostent *) 0x0
(gdb)
>How-To-Repeat:
caused by wrong configuration of host name

% hostname
Unknown

set hostname correctly, no problem.
>Fix:
in this case, apache should report error:"wrong hostname" or any other.
>Release-Note:
>Audit-Trail:
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