From 45a125c1d6aaa2352c5ec04eecba322930e6d169 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.
Bug: http://curl.haxx.se/docs/adv_20141105.html
CVE: CVE-2014-3707
Reported-By: Symeon Paraschoudis
Upstream-commit: b3875606925536f82fc61f3114ac42f29eaf6945
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
lib/formdata.c | 50 ++++++++------------------------------------------
lib/strdup.c | 29 ++++++++++++++++++++++++++---
lib/strdup.h | 1 +
lib/url.c | 19 +++++++++++++++----
lib/urldata.h | 11 +++++++++--
src/Makefile.in | 3 +--
src/Makefile.inc | 1 -
7 files changed, 60 insertions(+), 54 deletions(-)
diff --git a/lib/formdata.c b/lib/formdata.c
index 3260928..050f538 100644
--- a/lib/formdata.c
+++ b/lib/formdata.c
@@ -39,6 +39,7 @@
#include "strequal.h"
#include "curl_memory.h"
#include "sendf.h"
+#include "strdup.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
@@ -216,46 +217,6 @@ static const char * ContentTypeForFilename (const char *filename,
/***************************************************************************
*
- * 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.
@@ -684,7 +645,10 @@ CURLFORMcode FormAdd(struct curl_httppost **httppost,
app passed in a bad combo, so we better check for that first. */
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;
@@ -695,7 +659,9 @@ CURLFORMcode FormAdd(struct curl_httppost **httppost,
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;
diff --git a/lib/strdup.c b/lib/strdup.c
index 3b776b1..14f370f 100644
--- a/lib/strdup.c
+++ b/lib/strdup.c
@@ -19,12 +19,13 @@
* 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)
@@ -50,3 +51,25 @@ char *curlx_strdup(const char *str)
}
#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..36cc430 100644
--- a/lib/strdup.h
+++ b/lib/strdup.h
@@ -26,5 +26,6 @@
#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 b0aade1..0aa5a33 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -123,6 +123,7 @@ int curl_win32_idn_to_ascii(const char *in, char **out);
#include "bundles.h"
#include "conncache.h"
#include "multihandle.h"
+#include "strdup.h"
#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>
@@ -344,14 +345,24 @@ CURLcode Curl_dupset(struct SessionHandle * dst, struct SessionHandle * src)
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;
}
/*
diff --git a/lib/urldata.h b/lib/urldata.h
index 640cbb1..d03440b 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1337,7 +1337,6 @@ enum dupstring {
STRING_KRB_LEVEL, /* krb security level */
STRING_NETRC_FILE, /* if not NULL, use this instead of trying to find
$HOME/.netrc */
- STRING_COPYPOSTFIELDS, /* if POST, set the fields' values here */
STRING_PROXY, /* proxy to use */
STRING_SET_RANGE, /* range, if used */
STRING_SET_REFERER, /* custom string for the HTTP referer field */
@@ -1376,7 +1375,15 @@ enum dupstring {
STRING_TLSAUTH_PASSWORD, /* TLS auth <password> */
#endif
- /* -- end of strings -- */
+ /* -- end of zero-terminated strings -- */
+
+ STRING_LASTZEROTERMINATED,
+
+ /* -- below this are pointers to binary data that cannot be strdup'ed.
+ Each such pointer must be added manually to Curl_dupset() --- */
+
+ STRING_COPYPOSTFIELDS, /* if POST, set the fields' values here */
+
STRING_LAST /* not used, just an end-of-list marker */
};
diff --git a/src/Makefile.in b/src/Makefile.in
index 86e3d3a..74e8b9e 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -111,7 +111,7 @@ am__objects_1 = curl-tool_binmode.$(OBJEXT) curl-tool_bname.$(OBJEXT) \
curl-tool_urlglob.$(OBJEXT) curl-tool_util.$(OBJEXT) \
curl-tool_vms.$(OBJEXT) curl-tool_writeenv.$(OBJEXT) \
curl-tool_writeout.$(OBJEXT) curl-tool_xattr.$(OBJEXT)
-am__objects_2 = curl-strtoofft.$(OBJEXT) curl-strdup.$(OBJEXT) \
+am__objects_2 = curl-strtoofft.$(OBJEXT) \
curl-rawstr.$(OBJEXT) curl-nonblock.$(OBJEXT)
am__objects_3 =
am_curl_OBJECTS = $(am__objects_1) $(am__objects_2) $(am__objects_3)
@@ -376,7 +376,6 @@ AM_CPPFLAGS = -I$(top_builddir)/include/curl -I$(top_builddir)/include \
# 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
diff --git a/src/Makefile.inc b/src/Makefile.inc
index 3f9044d..ea81000 100644
--- a/src/Makefile.inc
+++ b/src/Makefile.inc
@@ -11,7 +11,6 @@
# 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
--
2.1.0