Received: (qmail 16088 invoked by uid 2012); 10 Dec 1997 18:21:11 -0000
Message-Id: <19971210182111.16087.qmail@hyperreal.org>
Date: 10 Dec 1997 18:21:11 -0000
From: M.D.Parker <mdpc@netcom.com>
Reply-To: mdpc@netcom.com
To: apbugs@hyperreal.org
Subject: suexec.c -- Does not report exec failure reasons
X-Send-Pr-Version: 3.2

>Number:         1543
>Category:       suexec
>Synopsis:       suexec.c -- Does not report exec failure reasons
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    apache
>State:          closed
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Wed Dec 10 10:30:01 PST 1997
>Last-Modified:  Wed Jan 21 14:26:03 PST 1998
>Originator:     mdpc@netcom.com
>Organization:
>Release:        1.3b3
>Environment:
UNIX based -- various vendors
>Description:
This is an issue that I discovered in analysis of the "unable to exec" message
from suexec for a file did not have permission bits set appropriately.  User
error, but hard to easily spot from the simple catchall error message.  The
specific scenario follows:

If you are running apache 1.3 without using the suexec wrapper, there is a 
check in mod_cgi.c to verify if the requested file is executable.  If not, an
entry is made in the error log with an appropriate statement.  This test is 
explicitly bypassed in mod_cgi.c and with GOOD reason.

However, in suexec.c a problem in the executable bits setting can only be
determined after an exec error.  Also, I understand why this is.  However, only
the exec failure is reported without any reason.  I suggest changing this so that
the error code (errno) is at least output with the exec error message so that
server administrator has some hope of attempting to correct the problem
easily.
>How-To-Repeat:
easily....
>Fix:
the suggested fix is in the description but no code.  Sorry :-%2
>Audit-Trail:

From: Marc Slemko <marcs@znep.com>
To: "M.D.Parker" <mdpc@netcom.com>
Cc: apbugs@hyperreal.org
Subject: Re: suexec/1543: suexec.c -- Does not report exec failure reasons
Date: Wed, 10 Dec 1997 20:29:44 -0700 (MST)

 On 10 Dec 1997, M.D.Parker wrote:
 > However, in suexec.c a problem in the executable bits setting can only be
 > determined after an exec error.  Also, I understand why this is.  However, only
 > the exec failure is reported without any reason.  I suggest changing this so that
 > the error code (errno) is at least output with the exec error message so that
 > server administrator has some hope of attempting to correct the problem
 > easily.
 
 Like this?
 
 Index: suexec.c
 ===================================================================
 RCS file: /export/home/cvs/apachen/src/support/suexec.c,v
 retrieving revision 1.29
 diff -u -r1.29 suexec.c
 --- suexec.c	1997/10/22 20:30:46	1.29
 +++ suexec.c	1997/12/11 03:26:34
 @@ -68,19 +68,21 @@
   */
  
  
 -#include "suexec.h"
 -
  #include <sys/param.h>
 -#include <stdlib.h>
 -#include <unistd.h>
 +#include <sys/stat.h>
  #include <sys/types.h>
 -#include <stdio.h>
 +
 +#include <errno.h>
 +#include <grp.h>
 +#include <pwd.h>
  #include <stdarg.h>
 +#include <stdio.h>
 +#include <stdlib.h>
  #include <string.h>
 -#include <pwd.h>
 -#include <grp.h>
  #include <time.h>
 -#include <sys/stat.h>
 +#include <unistd.h>
 +
 +#include "suexec.h"
  
  /*
   ***********************************************************************
 @@ -498,6 +500,6 @@
       *
       * Oh well, log the failure and error out.
       */
 -    log_err("exec failed (%s)\n", cmd);
 +    log_err("(%d)%s: exec failed (%s)\n", errno, strerror(errno), cmd);
      exit(255);
  }
 

From: "M. D. Parker" <mdpc@netcom.com>
To: Marc Slemko <marcs@znep.com>
Cc: apbugs@hyperreal.org
Subject: Re: suexec/1543: suexec.c -- Does not report exec failure reasons
Date: Fri, 12 Dec 97 11:41:44 PST

 Problem with the patch seems to be in the evaluation of the parameters
 pushed onto the stack before the call.  It seems that at least in my gcc
 implementation, the value of errno gets changed before being printed out,
 but the strerror() call reports the right textual error.
 
 Suggest that you change the patch as follows:
 
 .
 .
 .
 int errx;	/* error numb holder */
 .
 .
 .
         errx=errno;
     log_err("(%d)%s: exec failed (%s)\n", errx, strerror(errx), cmd);
 
 Mike
Release-Changed-From-To: 1.3-1.3b3
Release-Changed-By: Lars.Eilebrecht@unix-ag.org
Release-Changed-When: Sat Jan 10 05:33:45 PST 1998
State-Changed-From-To: open-closed
State-Changed-By: dgaudet
State-Changed-When: Wed Jan 21 14:26:03 PST 1998
State-Changed-Why:
A fix has been applied to 1.3b4-dev.

Thanks
Dean
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