source: trunk/server/common/patches/httpd-suexec-scripts.patch @ 1565

Last change on this file since 1565 was 1474, checked in by ezyang, 14 years ago
Specify uid 102 is signup, and remove dead SELinux code.
File size: 8.9 KB
RevLine 
[1]1# scripts.mit.edu httpd suexec patch
[823]2# Copyright (C) 2006, 2007, 2008  Jeff Arnold <jbarnold@mit.edu>,
3#                                 Joe Presbrey <presbrey@mit.edu>,
4#                                 Anders Kaseorg <andersk@mit.edu>,
5#                                 Geoffrey Thomas <geofft@mit.edu>
[1]6#
7# This program is free software; you can redistribute it and/or
8# modify it under the terms of the GNU General Public License
9# as published by the Free Software Foundation; either version 2
10# of the License, or (at your option) any later version.
11#
12# This program is distributed in the hope that it will be useful,
13# but WITHOUT ANY WARRANTY; without even the implied warranty of
14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15# GNU General Public License for more details.
16#
17# You should have received a copy of the GNU General Public License
18# along with this program; if not, write to the Free Software
19# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
20#
21# See /COPYRIGHT in this repository for more information.
22#
[103]23--- httpd-2.2.2/support/Makefile.in.old 2005-07-06 19:15:34.000000000 -0400
24+++ httpd-2.2.2/support/Makefile.in     2007-01-20 17:12:51.000000000 -0500
25@@ -60,7 +60,7 @@
26
27 suexec_OBJECTS = suexec.lo
28 suexec: $(suexec_OBJECTS)
29-       $(LINK) $(suexec_OBJECTS)
30+       $(LINK) -lselinux $(suexec_OBJECTS)
31
32 htcacheclean_OBJECTS = htcacheclean.lo
33 htcacheclean: $(htcacheclean_OBJECTS)
[823]34--- httpd-2.2.2/configure.in.old        2007-07-17 10:48:25.000000000 -0400
35+++ httpd-2.2.2/configure.in    2008-08-29 08:15:41.000000000 -0400
36@@ -559,6 +559,10 @@
37 APACHE_HELP_STRING(--with-suexec-userdir,User subdirectory),[
38   AC_DEFINE_UNQUOTED(AP_USERDIR_SUFFIX, "$withval", [User subdirectory] ) ] )
39 
40+AC_ARG_WITH(suexec-trusteddir,
41+APACHE_HELP_STRING(--with-suexec-trusteddir,Trusted SuExec directory),[
42+  AC_DEFINE_UNQUOTED(AP_TRUSTED_DIRECTORY, "$withval", [Trusted SuExec directory] ) ] )
43+
44 AC_ARG_WITH(suexec-docroot,
45 APACHE_HELP_STRING(--with-suexec-docroot,SuExec root directory),[
46   AC_DEFINE_UNQUOTED(AP_DOC_ROOT, "$withval", [SuExec root directory] ) ] )
[1259]47--- httpd-2.2.11/support/suexec.c.old   2008-11-30 10:47:31.000000000 -0500
48+++ httpd-2.2.11/support/suexec.c       2009-06-08 09:02:17.000000000 -0400
[842]49@@ -30,6 +30,9 @@
[298]50  *
51  */
52 
53+#define STATIC_CAT_PATH "/usr/local/bin/static-cat"
[842]54+#define PHP_PATH "/usr/bin/php-cgi"
[298]55+
56 #include "apr.h"
57 #include "ap_config.h"
58 #include "suexec.h"
[1259]59@@ -46,6 +49,7 @@
[103]60 #include <stdio.h>
61 #include <stdarg.h>
62 #include <stdlib.h>
63+#include <selinux/selinux.h>
64 
65 #ifdef HAVE_PWD_H
66 #include <pwd.h>
[1259]67@@ -95,6 +99,7 @@
[1]68 {
69     /* variable name starts with */
70     "HTTP_",
71+    "HTTPS_",
72     "SSL_",
73 
74     /* variable name is */
[1464]75@@ -245,9 +250,69 @@
[298]76     environ = cleanenv;
77 }
78 
79+static const char *static_extensions[] = {
80+    "html",
81+    "css",
82+    "gif",
83+    "jpg",
84+    "png",
85+    "htm",
86+    "jpeg",
87+    "js",
88+    "ico",
89+    "xml",
90+    "xsl",
91+    "tiff",
92+    "tif",
93+    "tgz",
94+    "tar",
95+    "jar",
96+    "zip",
97+    "pdf",
98+    "ps",
99+    "doc",
100+    "xls",
101+    "ppt",
102+    "swf",
103+    "mp3",
104+    "mov",
105+    "wmv",
106+    "mpg",
107+    "mpeg",
108+    "avi",
109+    "il",
[315]110+    "xhtml",
[618]111+    "svg",
[944]112+    "xaml",
113+    "xap",
[1464]114+    "wav",
115+    "mid",
116+    "midi",
[298]117+    NULL
118+};
119+
120+static int is_static_extension(const char *file)
121+{
122+    const char *extension = strrchr(file, '.');
123+    const char **p;
124+    if (extension == NULL) return 0;
125+    for (p = static_extensions; *p; ++p) {
[1464]126+        if (strcasecmp(extension + 1, *p) == 0) return 1;
[298]127+    }
128+    return 0;
129+}
130+
[842]131+static int is_php_extension(const char *file)
132+{
133+    const char *extension = strrchr(file, '.');
134+    if (extension == NULL) return 0;
135+    return strcmp(extension + 1, "php") == 0;
136+}
137+
[298]138 int main(int argc, char *argv[])
139 {
140     int userdir = 0;        /* ~userdir flag             */
[823]141+    int trusteddir = 0;     /* TRUSTED_DIRECTORY flag    */
142     uid_t uid;              /* user information          */
143     gid_t gid;              /* target group placeholder  */
144     char *target_uname;     /* target user name          */
[1169]145@@ -268,6 +331,7 @@
146      * Start with a "clean" environment
147      */
148     clean_env();
149+    setenv("JAVA_TOOL_OPTIONS", "-Xmx128M", 1); /* scripts.mit.edu local hack */
[1259]150 
[1169]151     prog = argv[0];
152     /*
[1259]153@@ -350,6 +414,20 @@
[823]154 #endif /*_OSD_POSIX*/
155 
156     /*
157+     * First check if this is an absolute path to the directory
158+     * of trusted executables. These are supposed to be security
159+     * audited to check parameters and validity on their own...
160+     */
161+    if (strstr(cmd, AP_TRUSTED_DIRECTORY) == cmd) {
162+        if (strstr(cmd, "/../") != NULL) {
163+            log_err("invalid command (%s)\n", cmd);
164+            exit(104);
165+        }
166+        trusteddir = 1;
167+        goto TRUSTED_DIRECTORY;
168+    }
169+
170+    /*
171      * Check for a leading '/' (absolute path) in the command to be executed,
172      * or attempts to back up out of the current directory,
173      * to protect against attacks.  If any are
[1259]174@@ -371,6 +449,7 @@
[823]175         userdir = 1;
176     }
177 
178+TRUSTED_DIRECTORY:
179     /*
180      * Error out if the target username is invalid.
181      */
[1259]182@@ -452,7 +531,7 @@
[103]183      * Error out if attempt is made to execute as root or as
184      * a UID less than AP_UID_MIN.  Tsk tsk.
185      */
186-    if ((uid == 0) || (uid < AP_UID_MIN)) {
[1474]187+    if ((uid == 0) || (uid < AP_UID_MIN && uid != 102)) { /* uid 102 = signup  */
[103]188         log_err("cannot run as forbidden uid (%d/%s)\n", uid, cmd);
189         exit(107);
190     }
[1474]191@@ -484,6 +563,7 @@
[103]192         log_err("failed to setuid (%ld: %s)\n", uid, cmd);
193         exit(110);
194     }
[908]195+    setenv("HOME", target_homedir, 1);
[103]196 
197     /*
198      * Get the current working directory, as well as the proper
[1259]199@@ -506,6 +600,21 @@
[823]200             log_err("cannot get docroot information (%s)\n", target_homedir);
201             exit(112);
[1]202         }
[823]203+        size_t expected_len = strlen(target_homedir)+1+strlen(AP_USERDIR_SUFFIX)+1;
204+        char *expected = malloc(expected_len);
205+        snprintf(expected, expected_len, "%s/%s", target_homedir, AP_USERDIR_SUFFIX);
206+        if (strncmp(cwd, expected, expected_len-1) != 0) {
207+            log_err("error: file's directory not a subdirectory of user's home directory (%s, %s)\n", cwd, expected);
208+            exit(114);
209+        }
210+    }
211+    else if (trusteddir) {
212+        if (((chdir(AP_TRUSTED_DIRECTORY)) != 0) ||
213+            ((getcwd(dwd, AP_MAXPATH)) == NULL) |
214+            ((chdir(cwd)) != 0)) {
215+            log_err("cannot get docroot information (%s)\n", AP_TRUSTED_DIRECTORY);
216+            exit(112);
217+        }
[1]218     }
[823]219     else {
220         if (((chdir(AP_DOC_ROOT)) != 0) ||
[1259]221@@ -532,15 +641,17 @@
[1]222     /*
223      * Error out if cwd is writable by others.
224      */
225+#if 0
226     if ((dir_info.st_mode & S_IWOTH) || (dir_info.st_mode & S_IWGRP)) {
227         log_err("directory is writable by others: (%s)\n", cwd);
228         exit(116);
229     }
230+#endif
231 
232     /*
233      * Error out if we cannot stat the program.
234      */
235-    if (((lstat(cmd, &prg_info)) != 0) || (S_ISLNK(prg_info.st_mode))) {
236+    if (((lstat(cmd, &prg_info)) != 0) /*|| (S_ISLNK(prg_info.st_mode))*/) {
237         log_err("cannot stat program: (%s)\n", cmd);
238         exit(117);
239     }
[1259]240@@ -548,10 +659,12 @@
[1]241     /*
242      * Error out if the program is writable by others.
243      */
244+#if 0
245     if ((prg_info.st_mode & S_IWOTH) || (prg_info.st_mode & S_IWGRP)) {
246         log_err("file is writable by others: (%s/%s)\n", cwd, cmd);
247         exit(118);
248     }
249+#endif
250 
251     /*
252      * Error out if the file is setuid or setgid.
[1259]253@@ -565,6 +678,7 @@
[1]254      * Error out if the target name/group is different from
255      * the name/group of the cwd or the program.
256      */
257+#if 0
258     if ((uid != dir_info.st_uid) ||
259         (gid != dir_info.st_gid) ||
260         (uid != prg_info.st_uid) ||
[1355]261@@ -576,12 +690,14 @@
[1]262                 prg_info.st_uid, prg_info.st_gid);
263         exit(120);
264     }
265+#endif
266     /*
267      * Error out if the program is not executable for the user.
268      * Otherwise, she won't find any error in the logs except for
[842]269      * "[error] Premature end of script headers: ..."
270      */
271-    if (!(prg_info.st_mode & S_IXUSR)) {
272+    if (!is_static_extension(cmd) && !is_php_extension(cmd) &&
[873]273+        !(prg_info.st_mode & S_IXUSR)) {
[842]274         log_err("file has no execute permission: (%s/%s)\n", cwd, cmd);
[873]275         exit(121);
[842]276     }
[1355]277@@ -614,6 +730,20 @@
278     /*
279      * Execute the command, replacing our image with its own.
280      */
[298]281+    if (is_static_extension(cmd)) {
282+        argv[2] = STATIC_CAT_PATH;
283+        execv(STATIC_CAT_PATH, &argv[2]);
[1259]284+        log_err("(%d)%s: static_cat exec failed (%s)\n", errno, strerror(errno), argv[2]);
285+        exit(255);
[298]286+    }
[842]287+    if (is_php_extension(cmd)) {
288+        setenv("PHPRC", ".", 1);
289+        argv[1] = PHP_PATH;
290+        argv[2] = "-f";
291+        execv(PHP_PATH, &argv[1]);
[1354]292+        log_err("(%d)%s: php exec failed (%s)\n", errno, strerror(errno), argv[1]);
[1259]293+        exit(255);
[842]294+    }
[1355]295 #ifdef NEED_HASHBANG_EMUL
296     /* We need the #! emulation when we want to execute scripts */
297     {
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