general/3307: Bug in alloc.c causes "Premature end of script headers"

["J.Kean Johnston" <jk...@sco.com>]

>Number:         3307
>Category:       general
>Synopsis:       Bug in alloc.c causes "Premature end of script headers"
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Wed Oct 28 09:50:00 PST 1998
>Last-Modified:
>Originator:     jkj@sco.com
>Organization:
apache
>Release:        1.3.3
>Environment:
SCO UnixWare 7 Release 7.0.1
SCO OpenServer Release 5.0.x
>Description:
Please refer to (at least) PR#3250 and 3256. They were closed incorectly
assuming the bug was in mod_perl or PHP 3.0.5. Its not. Compiling with those
things simply exposes the problem. See below for fix.
>How-To-Repeat:
Compile Apache 1.3.3 with mod_perl 1.16 and PHP 3.0.5 and try to run ANY
CGI bin program. It will fail. It has on both SCO Oses, and judging from the
previously mentioed PR's, Linux and other OSes as well.
>Fix:
in main/alloc.c, in function run_child_cleanups() you call the function
pointer c->child_cleanup() without checking the pointer first. Simply
putting in a line before that which reads:
  if (c->child_cleanup)
makes the problem go away.

In the function immediately above it, in run_cleanups(), you may want to
put in a similar check. I dont know if the pointer should ever be able to
be NULL, but putting in the safety net sure can't harm anything. If it should
be impossible for the pointer to be NULL, then perhaps putting in this fix
will hide a deeper problem. I dont know - I leave it up to people who know
Apache internals well to make that call.
>Audit-Trail:
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