X-Git-Url: https://granicus.if.org/sourcecode?a=blobdiff_plain;f=support%2Fsuexec.c;h=0b2491e28b394985edb6e3db98598f044b985472;hb=633a12126d456489ccccfd0bdbc2bffb57e30083;hp=34d37346e9f70e473cea17835d66584e9ff9f606;hpb=d5fe728b25b8030a7afc93f6d166ce851788640f;p=apache

diff --git a/support/suexec.c b/support/suexec.c
index 34d37346e9..0b2491e28b 100644
--- a/support/suexec.c
+++ b/support/suexec.c
@@ -1,55 +1,17 @@
-/* ====================================================================
- * The Apache Software License, Version 1.1
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
  *
- * Copyright (c) 2000-2001 The Apache Software Foundation.  All rights
- * reserved.
+ *     http://www.apache.org/licenses/LICENSE-2.0
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in
- *    the documentation and/or other materials provided with the
- *    distribution.
- *
- * 3. The end-user documentation included with the redistribution,
- *    if any, must include the following acknowledgment:
- *       "This product includes software developed by the
- *        Apache Software Foundation (http://www.apache.org/)."
- *    Alternately, this acknowledgment may appear in the software itself,
- *    if and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "Apache" and "Apache Software Foundation" must
- *    not be used to endorse or promote products derived from this
- *    software without prior written permission. For written
- *    permission, please contact apache@apache.org.
- *
- * 5. Products derived from this software may not be called "Apache",
- *    nor may "Apache" appear in their name, without prior written
- *    permission of the Apache Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- * ====================================================================
- *
- * This software consists of voluntary contributions made by many
- * individuals on behalf of the Apache Software Foundation.  For more
- * information on the Apache Software Foundation, please see
- * <http://www.apache.org/>.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
  */
 
 /*
@@ -58,8 +20,8 @@
  ***********************************************************************
  *
  * NOTE! : DO NOT edit this code!!!  Unless you know what you are doing,
- *         editing this code might open up your system in unexpected 
- *         ways to would-be crackers.  Every precaution has been taken 
+ *         editing this code might open up your system in unexpected
+ *         ways to would-be crackers.  Every precaution has been taken
  *         to make this code as safe as possible; alter it at your own
  *         risk.
  *
@@ -68,7 +30,10 @@
  *
  */
 
+#include "apr.h"
 #include "ap_config.h"
+#include "suexec.h"
+
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -81,8 +46,9 @@
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
-
-#include "suexec.h"
+#if APR_HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
 
 #ifdef HAVE_PWD_H
 #include <pwd.h>
@@ -92,24 +58,6 @@
 #include <grp.h>
 #endif
 
-/*
- ***********************************************************************
- * There is no initgroups() in QNX, so I believe this is safe :-)
- * Use cc -osuexec -3 -O -mf -DQNX suexec.c to compile.
- *
- * May 17, 1997.
- * Igor N. Kovalenko -- infoh@mail.wplus.net
- ***********************************************************************
- */
-
-#if defined(NEED_INITGROUPS)
-int initgroups(const char *name, gid_t basegid)
-{
-/* QNX and MPE do not appear to support supplementary groups. */
-    return 0;
-}
-#endif
-
 #if defined(PATH_MAX)
 #define AP_MAXPATH PATH_MAX
 #elif defined(MAXPATHLEN)
@@ -123,71 +71,100 @@ int initgroups(const char *name, gid_t basegid)
 extern char **environ;
 static FILE *log = NULL;
 
-char *safe_env_lst[] =
+static const char *const safe_env_lst[] =
 {
-    "AUTH_TYPE",
-    "CONTENT_LENGTH",
-    "CONTENT_TYPE",
-    "DATE_GMT",
-    "DATE_LOCAL",
-    "DOCUMENT_NAME",
-    "DOCUMENT_PATH_INFO",
-    "DOCUMENT_ROOT",
-    "DOCUMENT_URI",
-    "FILEPATH_INFO",
-    "GATEWAY_INTERFACE",
-    "LAST_MODIFIED",
-    "PATH_INFO",
-    "PATH_TRANSLATED",
-    "QUERY_STRING",
-    "QUERY_STRING_UNESCAPED",
-    "REMOTE_ADDR",
-    "REMOTE_HOST",
-    "REMOTE_IDENT",
-    "REMOTE_PORT",
-    "REMOTE_USER",
-    "REDIRECT_QUERY_STRING",
-    "REDIRECT_STATUS",
-    "REDIRECT_URL",
-    "REQUEST_METHOD",
-    "REQUEST_URI",
-    "SCRIPT_FILENAME",
-    "SCRIPT_NAME",
-    "SCRIPT_URI",
-    "SCRIPT_URL",
-    "SERVER_ADMIN",
-    "SERVER_NAME",
-    "SERVER_ADDR",
-    "SERVER_PORT",
-    "SERVER_PROTOCOL",
-    "SERVER_SOFTWARE",
-    "UNIQUE_ID",
-    "USER_NAME",
-    "TZ",
+    /* variable name starts with */
+    "HTTP_",
+    "SSL_",
+
+    /* variable name is */
+    "AUTH_TYPE=",
+    "CONTENT_LENGTH=",
+    "CONTENT_TYPE=",
+    "CONTEXT_DOCUMENT_ROOT=",
+    "CONTEXT_PREFIX=",
+    "DATE_GMT=",
+    "DATE_LOCAL=",
+    "DOCUMENT_ARGS=",
+    "DOCUMENT_NAME=",
+    "DOCUMENT_PATH_INFO=",
+    "DOCUMENT_ROOT=",
+    "DOCUMENT_URI=",
+    "GATEWAY_INTERFACE=",
+    "HTTPS=",
+    "LAST_MODIFIED=",
+    "PATH_INFO=",
+    "PATH_TRANSLATED=",
+    "QUERY_STRING=",
+    "QUERY_STRING_UNESCAPED=",
+    "REMOTE_ADDR=",
+    "REMOTE_HOST=",
+    "REMOTE_IDENT=",
+    "REMOTE_PORT=",
+    "REMOTE_USER=",
+    "REDIRECT_ERROR_NOTES=",
+    "REDIRECT_HANDLER=",
+    "REDIRECT_QUERY_STRING=",
+    "REDIRECT_REMOTE_USER=",
+    "REDIRECT_SCRIPT_FILENAME=",
+    "REDIRECT_STATUS=",
+    "REDIRECT_URL=",
+    "REQUEST_METHOD=",
+    "REQUEST_URI=",
+    "REQUEST_SCHEME=",
+    "SCRIPT_FILENAME=",
+    "SCRIPT_NAME=",
+    "SCRIPT_URI=",
+    "SCRIPT_URL=",
+    "SERVER_ADMIN=",
+    "SERVER_NAME=",
+    "SERVER_ADDR=",
+    "SERVER_PORT=",
+    "SERVER_PROTOCOL=",
+    "SERVER_SIGNATURE=",
+    "SERVER_SOFTWARE=",
+    "UNIQUE_ID=",
+    "USER_NAME=",
+    "TZ=",
     NULL
 };
 
+static void log_err(const char *fmt,...) 
+    __attribute__((format(printf,1,2)));
+static void log_no_err(const char *fmt,...)  
+    __attribute__((format(printf,1,2)));
+static void err_output(int is_error, const char *fmt, va_list ap) 
+    __attribute__((format(printf,2,0)));
 
-static void err_output(const char *fmt, va_list ap)
+static void err_output(int is_error, const char *fmt, va_list ap)
 {
 #ifdef AP_LOG_EXEC
     time_t timevar;
     struct tm *lt;
 
     if (!log) {
-	if ((log = fopen(AP_LOG_EXEC, "a")) == NULL) {
-	    fprintf(stderr, "failed to open log file\n");
-	    perror("fopen");
-	    exit(1);
-	}
+#if defined(_LARGEFILE64_SOURCE) && HAVE_FOPEN64
+        if ((log = fopen64(AP_LOG_EXEC, "a")) == NULL) {
+#else
+        if ((log = fopen(AP_LOG_EXEC, "a")) == NULL) {
+#endif
+            fprintf(stderr, "suexec failure: could not open log file\n");
+            perror("fopen");
+            exit(1);
+        }
+    }
+
+    if (is_error) {
+        fprintf(stderr, "suexec policy violation: see suexec log for more "
+                        "details\n");
     }
 
     time(&timevar);
     lt = localtime(&timevar);
 
     fprintf(log, "[%d-%.2d-%.2d %.2d:%.2d:%.2d]: ",
-	    lt->tm_year + 1900, lt->tm_mon + 1, lt->tm_mday,
-	    lt->tm_hour, lt->tm_min, lt->tm_sec);
+            lt->tm_year + 1900, lt->tm_mon + 1, lt->tm_mday,
+            lt->tm_hour, lt->tm_min, lt->tm_sec);
 
     vfprintf(log, fmt, ap);
 
@@ -202,7 +179,19 @@ static void log_err(const char *fmt,...)
     va_list ap;
 
     va_start(ap, fmt);
-    err_output(fmt, ap);
+    err_output(1, fmt, ap); /* 1 == is_error */
+    va_end(ap);
+#endif /* AP_LOG_EXEC */
+    return;
+}
+
+static void log_no_err(const char *fmt,...)
+{
+#ifdef AP_LOG_EXEC
+    va_list ap;
+
+    va_start(ap, fmt);
+    err_output(0, fmt, ap); /* 0 == !is_error */
     va_end(ap);
 #endif /* AP_LOG_EXEC */
     return;
@@ -216,31 +205,39 @@ static void clean_env(void)
     int cidx = 0;
     int idx;
 
+    /* While cleaning the environment, the environment should be clean.
+     * (e.g. malloc() may get the name of a file for writing debugging info.
+     * Bad news if MALLOC_DEBUG_FILE is set to /etc/passwd.  Sprintf() may be
+     * susceptible to bad locale settings....)
+     * (from PR 2790)
+     */
+    char **envp = environ;
+    char *empty_ptr = NULL;
+
+    environ = &empty_ptr; /* VERY safe environment */
 
     if ((cleanenv = (char **) calloc(AP_ENVBUF, sizeof(char *))) == NULL) {
         log_err("failed to malloc memory for environment\n");
-	exit(120);
+        exit(123);
     }
 
     sprintf(pathbuf, "PATH=%s", AP_SAFE_PATH);
     cleanenv[cidx] = strdup(pathbuf);
+    if (cleanenv[cidx] == NULL) {
+        log_err("failed to malloc memory for environment\n");
+        exit(124);
+    }
     cidx++;
 
-    for (ep = environ; *ep && cidx < AP_ENVBUF-1; ep++) {
-	if (!strncmp(*ep, "HTTP_", 5)) {
-	    cleanenv[cidx] = *ep;
-	    cidx++;
-	}
-	else {
-	    for (idx = 0; safe_env_lst[idx]; idx++) {
-		if (!strncmp(*ep, safe_env_lst[idx],
-			     strlen(safe_env_lst[idx]))) {
-		    cleanenv[cidx] = *ep;
-		    cidx++;
-		    break;
-		}
-	    }
-	}
+    for (ep = envp; *ep && cidx < AP_ENVBUF-1; ep++) {
+        for (idx = 0; safe_env_lst[idx]; idx++) {
+            if (!strncmp(*ep, safe_env_lst[idx],
+                         strlen(safe_env_lst[idx]))) {
+                cleanenv[cidx] = *ep;
+                cidx++;
+                break;
+            }
+        }
     }
 
     cleanenv[cidx] = NULL;
@@ -250,32 +247,35 @@ static void clean_env(void)
 
 int main(int argc, char *argv[])
 {
-    int userdir = 0;		/* ~userdir flag             */
-    uid_t uid;			/* user information          */
-    gid_t gid;			/* target group placeholder  */
-    char *target_uname;		/* target user name          */
-    char *target_gname;		/* target group name         */
-    char *target_homedir;	/* target home directory     */
-    char *actual_uname;		/* actual user name          */
-    char *actual_gname;		/* actual group name         */
-    char *prog;			/* name of this program      */
-    char *cmd;			/* command to be executed    */
-    char cwd[AP_MAXPATH];	/* current working directory */
-    char dwd[AP_MAXPATH];	/* docroot working directory */
-    struct passwd *pw;		/* password entry holder     */
-    struct group *gr;		/* group entry holder        */
-    struct stat dir_info;	/* directory info holder     */
-    struct stat prg_info;	/* program info holder       */
-
-    prog = argv[0];
+    int userdir = 0;        /* ~userdir flag             */
+    uid_t uid;              /* user information          */
+    gid_t gid;              /* target group placeholder  */
+    char *target_uname;     /* target user name          */
+    char *target_gname;     /* target group name         */
+    char *target_homedir;   /* target home directory     */
+    char *actual_uname;     /* actual user name          */
+    char *actual_gname;     /* actual group name         */
+    char *cmd;              /* command to be executed    */
+    char cwd[AP_MAXPATH];   /* current working directory */
+    char dwd[AP_MAXPATH];   /* docroot working directory */
+    struct passwd *pw;      /* password entry holder     */
+    struct group *gr;       /* group entry holder        */
+    struct stat dir_info;   /* directory info holder     */
+    struct stat prg_info;   /* program info holder       */
+
+    /*
+     * Start with a "clean" environment
+     */
+    clean_env();
+
     /*
      * Check existence/validity of the UID of the user
      * running this program.  Error out if invalid.
      */
     uid = getuid();
     if ((pw = getpwuid(uid)) == NULL) {
-	log_err("crit: invalid uid: (%ld)\n", uid);
-	exit(102);
+        log_err("crit: invalid uid: (%lu)\n", (unsigned long)uid);
+        exit(102);
     }
     /*
      * See if this is a 'how were you compiled' request, and
@@ -322,8 +322,8 @@ int main(int argc, char *argv[])
      * all of them to variables.  Otherwise, error out.
      */
     if (argc < 4) {
-	log_err("too few arguments\n");
-	exit(101);
+        log_err("too few arguments\n");
+        exit(101);
     }
     target_uname = argv[1];
     target_gname = argv[2];
@@ -338,12 +338,12 @@ int main(int argc, char *argv[])
     /* User name comparisons are case insensitive on BS2000/OSD */
     if (strcasecmp(AP_HTTPD_USER, pw->pw_name)) {
         log_err("user mismatch (%s instead of %s)\n", pw->pw_name, AP_HTTPD_USER);
-	exit(103);
+        exit(103);
     }
 #else  /*_OSD_POSIX*/
     if (strcmp(AP_HTTPD_USER, pw->pw_name)) {
         log_err("user mismatch (%s instead of %s)\n", pw->pw_name, AP_HTTPD_USER);
-	exit(103);
+        exit(103);
     }
 #endif /*_OSD_POSIX*/
 
@@ -354,9 +354,9 @@ int main(int argc, char *argv[])
      * found, error out.  Naughty naughty crackers.
      */
     if ((cmd[0] == '/') || (!strncmp(cmd, "../", 3))
-	|| (strstr(cmd, "/../") != NULL)) {
+        || (strstr(cmd, "/../") != NULL)) {
         log_err("invalid command (%s)\n", cmd);
-	exit(104);
+        exit(104);
     }
 
     /*
@@ -365,8 +365,8 @@ int main(int argc, char *argv[])
      * target username.
      */
     if (!strncmp("~", target_uname, 1)) {
-	target_uname++;
-	userdir = 1;
+        target_uname++;
+        userdir = 1;
     }
 
     /*
@@ -374,13 +374,13 @@ int main(int argc, char *argv[])
      */
     if (strspn(target_uname, "1234567890") != strlen(target_uname)) {
         if ((pw = getpwnam(target_uname)) == NULL) {
-    	    log_err("invalid target user name: (%s)\n", target_uname);
-    	    exit(105);
+            log_err("invalid target user name: (%s)\n", target_uname);
+            exit(105);
         }
     }
     else {
         if ((pw = getpwuid(atoi(target_uname))) == NULL) {
-            log_err("invalud target user id: (%s)\n", target_uname);
+            log_err("invalid target user id: (%s)\n", target_uname);
             exit(121);
         }
     }
@@ -389,16 +389,21 @@ int main(int argc, char *argv[])
      * Error out if the target group name is invalid.
      */
     if (strspn(target_gname, "1234567890") != strlen(target_gname)) {
-	if ((gr = getgrnam(target_gname)) == NULL) {
-	    log_err("invalid target group name: (%s)\n", target_gname);
-	    exit(106);
-	}
-	gid = gr->gr_gid;
-	actual_gname = strdup(gr->gr_name);
+        if ((gr = getgrnam(target_gname)) == NULL) {
+            log_err("invalid target group name: (%s)\n", target_gname);
+            exit(106);
+        }
     }
     else {
-	gid = atoi(target_gname);
-	actual_gname = strdup(target_gname);
+        if ((gr = getgrgid(atoi(target_gname))) == NULL) {
+            log_err("invalid target group id: (%s)\n", target_gname);
+            exit(106);
+        }
+    }
+    gid = gr->gr_gid;
+    if ((actual_gname = strdup(gr->gr_name)) == NULL) {
+        log_err("failed to alloc memory\n");
+        exit(125);
     }
 
 #ifdef _OSD_POSIX
@@ -406,25 +411,25 @@ int main(int argc, char *argv[])
      * Initialize BS2000 user environment
      */
     {
-	pid_t pid;
-	int status;
-
-	switch (pid = ufork(target_uname))
-	{
-	case -1:	/* Error */
-	    log_err("failed to setup bs2000 environment for user %s: %s\n",
-		    target_uname, strerror(errno));
-	    exit(150);
-	case 0:	/* Child */
-	    break;
-	default:	/* Father */
-	    while (pid != waitpid(pid, &status, 0))
-		;
-	    /* @@@ FIXME: should we deal with STOP signals as well? */
-	    if (WIFSIGNALED(status))
-		kill (getpid(), WTERMSIG(status));
-	    exit(WEXITSTATUS(status));
-	}
+        pid_t pid;
+        int status;
+
+        switch (pid = ufork(target_uname)) {
+        case -1:    /* Error */
+            log_err("failed to setup bs2000 environment for user %s: %s\n",
+                    target_uname, strerror(errno));
+            exit(150);
+        case 0:     /* Child */
+            break;
+        default:    /* Father */
+            while (pid != waitpid(pid, &status, 0))
+                ;
+            /* @@@ FIXME: should we deal with STOP signals as well? */
+            if (WIFSIGNALED(status)) {
+                kill (getpid(), WTERMSIG(status));
+            }
+            exit(WEXITSTATUS(status));
+        }
     }
 #endif /*_OSD_POSIX*/
 
@@ -434,23 +439,27 @@ int main(int argc, char *argv[])
     uid = pw->pw_uid;
     actual_uname = strdup(pw->pw_name);
     target_homedir = strdup(pw->pw_dir);
+    if (actual_uname == NULL || target_homedir == NULL) {
+        log_err("failed to alloc memory\n");
+        exit(126);
+    }
 
     /*
-     * Log the transaction here to be sure we have an open log 
+     * Log the transaction here to be sure we have an open log
      * before we setuid().
      */
-    log_err("uid: (%s/%s) gid: (%s/%s) cmd: %s\n",
-	    target_uname, actual_uname,
-	    target_gname, actual_gname,
-	    cmd);
+    log_no_err("uid: (%s/%s) gid: (%s/%s) cmd: %s\n",
+               target_uname, actual_uname,
+               target_gname, actual_gname,
+               cmd);
 
     /*
      * Error out if attempt is made to execute as root or as
      * a UID less than AP_UID_MIN.  Tsk tsk.
      */
     if ((uid == 0) || (uid < AP_UID_MIN)) {
-	log_err("cannot run as forbidden uid (%d/%s)\n", uid, cmd);
-	exit(107);
+        log_err("cannot run as forbidden uid (%lu/%s)\n", (unsigned long)uid, cmd);
+        exit(107);
     }
 
     /*
@@ -458,8 +467,8 @@ int main(int argc, char *argv[])
      * or as a GID less than AP_GID_MIN.  Tsk tsk.
      */
     if ((gid == 0) || (gid < AP_GID_MIN)) {
-	log_err("cannot run as forbidden gid (%d/%s)\n", gid, cmd);
-	exit(108);
+        log_err("cannot run as forbidden gid (%lu/%s)\n", (unsigned long)gid, cmd);
+        exit(108);
     }
 
     /*
@@ -469,16 +478,16 @@ int main(int argc, char *argv[])
      * and setgid() to the target group. If unsuccessful, error out.
      */
     if (((setgid(gid)) != 0) || (initgroups(actual_uname, gid) != 0)) {
-	log_err("failed to setgid (%ld: %s)\n", gid, cmd);
-	exit(109);
+        log_err("failed to setgid (%lu: %s)\n", (unsigned long)gid, cmd);
+        exit(109);
     }
 
     /*
      * setuid() to the target user.  Error out on fail.
      */
     if ((setuid(uid)) != 0) {
-	log_err("failed to setuid (%ld: %s)\n", uid, cmd);
-	exit(110);
+        log_err("failed to setuid (%lu: %s)\n", (unsigned long)uid, cmd);
+        exit(110);
     }
 
     /*
@@ -490,71 +499,71 @@ int main(int argc, char *argv[])
      * directories.  Yuck.
      */
     if (getcwd(cwd, AP_MAXPATH) == NULL) {
-	log_err("cannot get current working directory\n");
-	exit(111);
+        log_err("cannot get current working directory\n");
+        exit(111);
     }
 
     if (userdir) {
-	if (((chdir(target_homedir)) != 0) ||
-	    ((chdir(AP_USERDIR_SUFFIX)) != 0) ||
-	    ((getcwd(dwd, AP_MAXPATH)) == NULL) ||
-	    ((chdir(cwd)) != 0)) {
-	    log_err("cannot get docroot information (%s)\n", target_homedir);
-	    exit(112);
-	}
+        if (((chdir(target_homedir)) != 0) ||
+            ((chdir(AP_USERDIR_SUFFIX)) != 0) ||
+            ((getcwd(dwd, AP_MAXPATH)) == NULL) ||
+            ((chdir(cwd)) != 0)) {
+            log_err("cannot get docroot information (%s)\n", target_homedir);
+            exit(112);
+        }
     }
     else {
-	if (((chdir(AP_DOC_ROOT)) != 0) ||
-	    ((getcwd(dwd, AP_MAXPATH)) == NULL) ||
-	    ((chdir(cwd)) != 0)) {
-	    log_err("cannot get docroot information (%s)\n", AP_DOC_ROOT);
-	    exit(113);
-	}
+        if (((chdir(AP_DOC_ROOT)) != 0) ||
+            ((getcwd(dwd, AP_MAXPATH)) == NULL) ||
+            ((chdir(cwd)) != 0)) {
+            log_err("cannot get docroot information (%s)\n", AP_DOC_ROOT);
+            exit(113);
+        }
     }
 
     if ((strncmp(cwd, dwd, strlen(dwd))) != 0) {
-	log_err("command not in docroot (%s/%s)\n", cwd, cmd);
-	exit(114);
+        log_err("command not in docroot (%s/%s)\n", cwd, cmd);
+        exit(114);
     }
 
     /*
      * Stat the cwd and verify it is a directory, or error out.
      */
     if (((lstat(cwd, &dir_info)) != 0) || !(S_ISDIR(dir_info.st_mode))) {
-	log_err("cannot stat directory: (%s)\n", cwd);
-	exit(115);
+        log_err("cannot stat directory: (%s)\n", cwd);
+        exit(115);
     }
 
     /*
      * Error out if cwd is writable by others.
      */
     if ((dir_info.st_mode & S_IWOTH) || (dir_info.st_mode & S_IWGRP)) {
-	log_err("directory is writable by others: (%s)\n", cwd);
-	exit(116);
+        log_err("directory is writable by others: (%s)\n", cwd);
+        exit(116);
     }
 
     /*
      * Error out if we cannot stat the program.
      */
     if (((lstat(cmd, &prg_info)) != 0) || (S_ISLNK(prg_info.st_mode))) {
-	log_err("cannot stat program: (%s)\n", cmd);
-	exit(117);
+        log_err("cannot stat program: (%s)\n", cmd);
+        exit(117);
     }
 
     /*
      * Error out if the program is writable by others.
      */
     if ((prg_info.st_mode & S_IWOTH) || (prg_info.st_mode & S_IWGRP)) {
-	log_err("file is writable by others: (%s/%s)\n", cwd, cmd);
-	exit(118);
+        log_err("file is writable by others: (%s/%s)\n", cwd, cmd);
+        exit(118);
     }
 
     /*
      * Error out if the file is setuid or setgid.
      */
     if ((prg_info.st_mode & S_ISUID) || (prg_info.st_mode & S_ISGID)) {
-	log_err("file is either setuid or setgid: (%s/%s)\n", cwd, cmd);
-	exit(119);
+        log_err("file is either setuid or setgid: (%s/%s)\n", cwd, cmd);
+        exit(119);
     }
 
     /*
@@ -562,15 +571,15 @@ int main(int argc, char *argv[])
      * the name/group of the cwd or the program.
      */
     if ((uid != dir_info.st_uid) ||
-	(gid != dir_info.st_gid) ||
-	(uid != prg_info.st_uid) ||
-	(gid != prg_info.st_gid)) {
-	log_err("target uid/gid (%ld/%ld) mismatch "
-		"with directory (%ld/%ld) or program (%ld/%ld)\n",
-		uid, gid,
-		dir_info.st_uid, dir_info.st_gid,
-		prg_info.st_uid, prg_info.st_gid);
-	exit(120);
+        (gid != dir_info.st_gid) ||
+        (uid != prg_info.st_uid) ||
+        (gid != prg_info.st_gid)) {
+        log_err("target uid/gid (%lu/%lu) mismatch "
+                "with directory (%lu/%lu) or program (%lu/%lu)\n",
+                (unsigned long)uid, (unsigned long)gid,
+                (unsigned long)dir_info.st_uid, (unsigned long)dir_info.st_gid,
+                (unsigned long)prg_info.st_uid, (unsigned long)prg_info.st_gid);
+        exit(120);
     }
     /*
      * Error out if the program is not executable for the user.
@@ -578,8 +587,8 @@ int main(int argc, char *argv[])
      * "[error] Premature end of script headers: ..."
      */
     if (!(prg_info.st_mode & S_IXUSR)) {
-	log_err("file has no execute permission: (%s/%s)\n", cwd, cmd);
-	exit(121);
+        log_err("file has no execute permission: (%s/%s)\n", cwd, cmd);
+        exit(121);
     }
 
 #ifdef AP_SUEXEC_UMASK
@@ -592,20 +601,28 @@ int main(int argc, char *argv[])
     }
     umask(AP_SUEXEC_UMASK);
 #endif /* AP_SUEXEC_UMASK */
-    clean_env();
 
-    /* 
-     * Be sure to close the log file so the CGI can't
-     * mess with it.  If the exec fails, it will be reopened 
-     * automatically when log_err is called.  Note that the log
-     * might not actually be open if AP_LOG_EXEC isn't defined.
-     * However, the "log" cell isn't ifdef'd so let's be defensive
-     * and assume someone might have done something with it
-     * outside an ifdef'd AP_LOG_EXEC block.
-     */
+    /* Be sure to close the log file so the CGI can't mess with it. */
     if (log != NULL) {
-	fclose(log);
-	log = NULL;
+#if APR_HAVE_FCNTL_H
+        /*
+         * ask fcntl(2) to set the FD_CLOEXEC flag on the log file,
+         * so it'll be automagically closed if the exec() call succeeds.
+         */
+        fflush(log);
+        setbuf(log, NULL);
+        if ((fcntl(fileno(log), F_SETFD, FD_CLOEXEC) == -1)) {
+            log_err("error: can't set close-on-exec flag");
+            exit(122);
+        }
+#else
+        /*
+         * In this case, exec() errors won't be logged because we have already
+         * dropped privileges and won't be able to reopen the log file.
+         */
+        fclose(log);
+        log = NULL;
+#endif
     }
 
     /*
@@ -614,9 +631,9 @@ int main(int argc, char *argv[])
 #ifdef NEED_HASHBANG_EMUL
     /* We need the #! emulation when we want to execute scripts */
     {
-	extern char **environ;
+        extern char **environ;
 
-	ap_execve(cmd, &argv[3], environ);
+        ap_execve(cmd, &argv[3], environ);
     }
 #else /*NEED_HASHBANG_EMUL*/
     execv(cmd, &argv[3]);
@@ -630,7 +647,6 @@ int main(int argc, char *argv[])
      *
      * Oh well, log the failure and error out.
      */
-    log_err("(%d)%s: exec failed (%s)\n", errno, 
-            strerror(errno), cmd);
+    log_err("(%d)%s: exec failed (%s)\n", errno, strerror(errno), cmd);
     exit(255);
 }