From 3696fc1ba79d9b34660c44150be5e93ecf87dd9e Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Fri, 17 Oct 2014 12:59:32 +0200
Subject: [PATCH] curl_easy_duphandle: CURLOPT_COPYPOSTFIELDS read out of
bounds
When duplicating a handle, the data to post was duplicated using
strdup() when it could be binary and contain zeroes and it was not even
zero terminated! This caused read out of bounds crashes/segfaults.
Since the lib/strdup.c file no longer is easily shared with the curl
tool with this change, it now uses its own version instead.
Bug: http://curl.haxx.se/docs/adv_20141105.html
CVE: CVE-2014-3707
Reported-By: Symeon Paraschoudis
---
lib/formdata.c | 52 +++++++++-------------------------------------------
lib/strdup.c | 32 +++++++++++++++++++++++++++-----
lib/strdup.h | 3 ++-
lib/url.c | 22 +++++++++++++++++-----
lib/urldata.h | 11 +++++++++--
src/Makefile.inc | 4 ++--
src/tool_setup.h | 5 ++---
src/tool_strdup.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
src/tool_strdup.h | 30 ++++++++++++++++++++++++++++++
9 files changed, 145 insertions(+), 61 deletions(-)
create mode 100644 src/tool_strdup.c
create mode 100644 src/tool_strdup.h
diff --git a/lib/formdata.c b/lib/formdata.c
index 1abfbc4..73d3b6d 100644
--- a/lib/formdata.c
+++ b/lib/formdata.c
@@ -34,10 +34,11 @@
#include "formdata.h"
#include "sslgen.h"
#include "strequal.h"
#include "curl_memory.h"
#include "sendf.h"
+#include "strdup.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
/* The last #include file should be: */
@@ -208,50 +209,10 @@ static const char *ContentTypeForFilename(const char *filename,
return contenttype;
}
/***************************************************************************
*
- * memdup()
- *
- * Copies the 'source' data to a newly allocated buffer buffer (that is
- * returned). Uses buffer_length if not null, else uses strlen to determine
- * the length of the buffer to be copied
- *
- * Returns the new pointer or NULL on failure.
- *
- ***************************************************************************/
-static char *memdup(const char *src, size_t buffer_length)
-{
- size_t length;
- bool add = FALSE;
- char *buffer;
-
- if(buffer_length)
- length = buffer_length;
- else if(src) {
- length = strlen(src);
- add = TRUE;
- }
- else
- /* no length and a NULL src pointer! */
- return strdup("");
-
- buffer = malloc(length+add);
- if(!buffer)
- return NULL; /* fail */
-
- memcpy(buffer, src, length);
-
- /* if length unknown do null termination */
- if(add)
- buffer[length] = '\0';
-
- return buffer;
-}
-
-/***************************************************************************
- *
* FormAdd()
*
* Stores a formpost parameter and builds the appropriate linked list.
*
* Has two principal functionalities: using files and byte arrays as
@@ -676,24 +637,29 @@ CURLFORMcode FormAdd(struct curl_httppost **httppost,
}
if(!(form->flags & HTTPPOST_PTRNAME) &&
(form == first_form) ) {
/* Note that there's small risk that form->name is NULL here if the
app passed in a bad combo, so we better check for that first. */
- if(form->name)
+ if(form->name) {
/* copy name (without strdup; possibly contains null characters) */
- form->name = memdup(form->name, form->namelength);
+ form->name = Curl_memdup(form->name, form->namelength?
+ form->namelength:
+ strlen(form->name)+1);
+ }
if(!form->name) {
return_value = CURL_FORMADD_MEMORY;
break;
}
form->name_alloc = TRUE;
}
if(!(form->flags & (HTTPPOST_FILENAME | HTTPPOST_READFILE |
HTTPPOST_PTRCONTENTS | HTTPPOST_PTRBUFFER |
HTTPPOST_CALLBACK)) ) {
/* copy value (without strdup; possibly contains null characters) */
- form->value = memdup(form->value, form->contentslength);
+ form->value = Curl_memdup(form->value, form->contentslength?
+ form->contentslength:
+ strlen(form->value)+1);
if(!form->value) {
return_value = CURL_FORMADD_MEMORY;
break;
}
form->value_alloc = TRUE;
diff --git a/lib/strdup.c b/lib/strdup.c
index 3b776b1..4b5bd40 100644
--- a/lib/strdup.c
+++ b/lib/strdup.c
@@ -3,11 +3,11 @@
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
- * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
@@ -17,16 +17,16 @@
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
-/*
- * This file is 'mem-include-scan' clean. See test 1132.
- */
#include "curl_setup.h"
-
#include "strdup.h"
+#include "curl_memory.h"
+
+/* The last #include file should be: */
+#include "memdebug.h"
#ifndef HAVE_STRDUP
char *curlx_strdup(const char *str)
{
size_t len;
@@ -48,5 +48,27 @@ char *curlx_strdup(const char *str)
return newstr;
}
#endif
+
+/***************************************************************************
+ *
+ * Curl_memdup(source, length)
+ *
+ * Copies the 'source' data to a newly allocated buffer (that is
+ * returned). Copies 'length' bytes.
+ *
+ * Returns the new pointer or NULL on failure.
+ *
+ ***************************************************************************/
+char *Curl_memdup(const char *src, size_t length)
+{
+ char *buffer = malloc(length);
+ if(!buffer)
+ return NULL; /* fail */
+
+ memcpy(buffer, src, length);
+
+ /* if length unknown do null termination */
+ return buffer;
+}
diff --git a/lib/strdup.h b/lib/strdup.h
index 49af911..23a71f8 100644
--- a/lib/strdup.h
+++ b/lib/strdup.h
@@ -5,11 +5,11 @@
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
- * Copyright (C) 1998 - 2010, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
@@ -24,7 +24,8 @@
#include "curl_setup.h"
#ifndef HAVE_STRDUP
extern char *curlx_strdup(const char *str);
#endif
+char *Curl_memdup(const char *src, size_t buffer_length);
#endif /* HEADER_CURL_STRDUP_H */
diff --git a/lib/url.c b/lib/url.c
index 4974a1a..40d4fed 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -123,10 +123,11 @@ int curl_win32_idn_to_ascii(const char *in, char **out);
#include "bundles.h"
#include "conncache.h"
#include "multihandle.h"
#include "pipeline.h"
#include "dotdot.h"
+#include "strdup.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
#include "curl_memory.h"
@@ -268,12 +269,13 @@ static const struct Curl_handler Curl_handler_dummy = {
void Curl_freeset(struct SessionHandle *data)
{
/* Free all dynamic strings stored in the data->set substructure. */
enum dupstring i;
- for(i=(enum dupstring)0; i < STRING_LAST; i++)
+ for(i=(enum dupstring)0; i < STRING_LAST; i++) {
Curl_safefree(data->set.str[i]);
+ }
if(data->change.referer_alloc) {
Curl_safefree(data->change.referer);
data->change.referer_alloc = FALSE;
}
@@ -354,18 +356,28 @@ CURLcode Curl_dupset(struct SessionHandle *dst, struct SessionHandle *src)
/* clear all string pointers first */
memset(dst->set.str, 0, STRING_LAST * sizeof(char *));
/* duplicate all strings */
- for(i=(enum dupstring)0; i< STRING_LAST; i++) {
+ for(i=(enum dupstring)0; i< STRING_LASTZEROTERMINATED; i++) {
r = setstropt(&dst->set.str[i], src->set.str[i]);
if(r != CURLE_OK)
- break;
+ return r;
}
- /* If a failure occurred, freeing has to be performed externally. */
- return r;
+ /* duplicate memory areas pointed to */
+ i = STRING_COPYPOSTFIELDS;
+ if(src->set.postfieldsize && src->set.str[i]) {
+ /* postfieldsize is curl_off_t, Curl_memdup() takes a size_t ... */
+ dst->set.str[i] = Curl_memdup(src->set.str[i], src->set.postfieldsize);
+ if(!dst->set.str[i])
+ return CURLE_OUT_OF_MEMORY;
+ /* point to the new copy */
+ dst->set.postfields = dst->set.str[i];
+ }
+
+ return CURLE_OK;
}
/*
* This is the internal function curl_easy_cleanup() calls. This should
* cleanup and free all resources associated with this sessionhandle.
diff --git a/lib/urldata.h b/lib/urldata.h
index 5a65c4a..62a2b80 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1370,11 +1370,10 @@ enum dupstring {
STRING_KEY_PASSWD, /* plain text private key password */
STRING_KEY_TYPE, /* format for private key (default: PEM) */
STRING_KRB_LEVEL, /* krb security level */
STRING_NETRC_FILE, /* if not NULL, use this instead of trying to find
$HOME/.netrc */
- STRING_COPYPOSTFIELDS, /* if POST, set the fields' values here */
STRING_PROXY, /* proxy to use */
STRING_SET_RANGE, /* range, if used */
STRING_SET_REFERER, /* custom string for the HTTP referer field */
STRING_SET_URL, /* what original URL to work on */
STRING_SSL_CAPATH, /* CA directory name (doesn't work on windows) */
@@ -1413,11 +1412,19 @@ enum dupstring {
STRING_TLSAUTH_PASSWORD, /* TLS auth <password> */
#endif
STRING_BEARER, /* <bearer>, if used */
- /* -- end of strings -- */
+ /* -- end of zero-terminated strings -- */
+
+ STRING_LASTZEROTERMINATED,
+
+ /* -- below this are pointers to binary data that cannot be strdup'ed.
+ Each such pointer must be added manually to Curl_dupset() --- */
+
+ STRING_COPYPOSTFIELDS, /* if POST, set the fields' values here */
+
STRING_LAST /* not used, just an end-of-list marker */
};
struct UserDefined {
FILE *err; /* the stderr user data goes here */
diff --git a/src/Makefile.inc b/src/Makefile.inc
index 64d55ec..401a635 100644
--- a/src/Makefile.inc
+++ b/src/Makefile.inc
@@ -9,11 +9,10 @@
# libcurl has sources that provide functions named curlx_* that aren't part of
# the official API, but we re-use the code here to avoid duplication.
CURLX_ONES = \
../lib/strtoofft.c \
- ../lib/strdup.c \
../lib/rawstr.c \
../lib/nonblock.c
CURL_CFILES = \
tool_binmode.c \
@@ -53,10 +51,11 @@ CURL_CFILES = \
tool_operate.c \
tool_operhlp.c \
tool_panykey.c \
tool_paramhlp.c \
tool_parsecfg.c \
+ tool_strdup.c \
tool_setopt.c \
tool_sleep.c \
tool_urlglob.c \
tool_util.c \
tool_vms.c \
@@ -97,10 +96,11 @@ CURL_HFILES = \
tool_parsecfg.h \
tool_sdecls.h \
tool_setopt.h \
tool_setup.h \
tool_sleep.h \
+ tool_strdup.h \
tool_urlglob.h \
tool_util.h \
tool_version.h \
tool_vms.h \
tool_writeenv.h \
diff --git a/src/tool_setup.h b/src/tool_setup.h
index c94686f..3d7c158 100644
--- a/src/tool_setup.h
+++ b/src/tool_setup.h
@@ -5,11 +5,11 @@
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
- * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at http://curl.haxx.se/docs/copyright.html.
*
@@ -65,11 +65,10 @@
/* define what to use for unprintable characters */
# define UNPRINTABLE_CHAR '.'
#endif
#ifndef HAVE_STRDUP
-# include "strdup.h"
-# define strdup(ptr) curlx_strdup(ptr)
+# include "tool_strdup.h"
#endif
#endif /* HEADER_CURL_TOOL_SETUP_H */
diff --git a/src/tool_strdup.c b/src/tool_strdup.c
new file mode 100644
index 0000000..d661a82
--- /dev/null
+++ b/src/tool_strdup.c
@@ -0,0 +1,47 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+#include "strdup.h"
+
+#ifndef HAVE_STRDUP
+char *strdup(const char *str)
+{
+ size_t len;
+ char *newstr;
+
+ if(!str)
+ return (char *)NULL;
+
+ len = strlen(str);
+
+ if(len >= ((size_t)-1) / sizeof(char))
+ return (char *)NULL;
+
+ newstr = malloc((len+1)*sizeof(char));
+ if(!newstr)
+ return (char *)NULL;
+
+ memcpy(newstr,str,(len+1)*sizeof(char));
+
+ return newstr;
+
+}
+#endif
diff --git a/src/tool_strdup.h b/src/tool_strdup.h
new file mode 100644
index 0000000..83c8102
--- /dev/null
+++ b/src/tool_strdup.h
@@ -0,0 +1,30 @@
+#ifndef HEADER_TOOL_STRDUP_H
+#define HEADER_TOOL_STRDUP_H
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+#include "tool_setup.h"
+
+#ifndef HAVE_STRDUP
+extern char *strdup(const char *str);
+#endif
+
+#endif /* HEADER_TOOL_STRDUP_H */
--
2.1.1
