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authorAlan Coopersmith <alan.coopersmith@oracle.com>2013-03-02 13:18:48 -0800
committerUlrich Sibiller <uli42@gmx.de>2016-10-12 09:34:38 +0200
commit25172302a39c4e0c90dffbdcfa88b99ac442a2f9 (patch)
treec52ae736bbfb3e8c9891a8f8eb58c65267e37001 /nx-X11
parent8468165ae6ec55c715721c6e1991f67902b30564 (diff)
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integer overflows in TransFileName() [CVE-2013-1981 9/13]
When trying to process file paths the tokens %H, %L, & %S are expanded to $HOME, the standard compose file path & the xlocaledir path. If enough of these tokens are repeated and values like $HOME are set to very large values, the calculation of the total string size required to hold the expanded path can overflow, resulting in allocating a smaller string than the amount of data we'll write to it. Simply restrict all of these values, and the total path size to PATH_MAX, because really, that's all you should need for a filename path. Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com> Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com> Reviewed-by: Matthieu Herrb <matthieu.herrb@laas.fr> Signed-off-by: Julien Cristau <jcristau@debian.org> Backported-to-NX-by: Ulrich Sibiller <uli42@gmx.de>
Diffstat (limited to 'nx-X11')
-rw-r--r--nx-X11/lib/X11/imLcPrs.c45
1 files changed, 34 insertions, 11 deletions
diff --git a/nx-X11/lib/X11/imLcPrs.c b/nx-X11/lib/X11/imLcPrs.c
index 5b9a2844e..f02e93bbb 100644
--- a/nx-X11/lib/X11/imLcPrs.c
+++ b/nx-X11/lib/X11/imLcPrs.c
@@ -42,6 +42,7 @@ OR PERFORMANCE OF THIS SOFTWARE.
#include <sys/stat.h>
#include <stdio.h>
#include <limits.h>
+#include "pathmax.h"
#define XLC_BUFSIZE 256
@@ -305,9 +306,9 @@ static char*
TransFileName(Xim im, char *name)
{
char *home = NULL, *lcCompose = NULL;
- char dir[XLC_BUFSIZE];
- char *i = name, *ret, *j;
- int l = 0;
+ char dir[XLC_BUFSIZE] = "";
+ char *i = name, *ret = NULL, *j;
+ size_t l = 0;
while (*i) {
if (*i == '%') {
@@ -317,30 +318,51 @@ TransFileName(Xim im, char *name)
l++;
break;
case 'H':
- home = getenv("HOME");
- if (home)
- l += strlen(home);
+ if (home == NULL)
+ home = getenv("HOME");
+ if (home) {
+ size_t Hsize = strlen(home);
+ if (Hsize > PATH_MAX)
+ /* your home directory length is ridiculous */
+ goto end;
+ l += Hsize;
+ }
break;
case 'L':
if (lcCompose == NULL)
lcCompose = _XlcFileName(im->core.lcd, COMPOSE_FILE);
- if (lcCompose)
- l += strlen(lcCompose);
+ if (lcCompose) {
+ size_t Lsize = strlen(lcCompose);
+ if (Lsize > PATH_MAX)
+ /* your compose pathname length is ridiculous */
+ goto end;
+ l += Lsize;
+ }
break;
case 'S':
- xlocaledir(dir, XLC_BUFSIZE);
- l += strlen(dir);
+ if (dir[0] == '\0')
+ xlocaledir(dir, XLC_BUFSIZE);
+ if (dir[0]) {
+ size_t Ssize = strlen(dir);
+ if (Ssize > PATH_MAX)
+ /* your locale directory path length is ridiculous */
+ goto end;
+ l += Ssize;
+ }
break;
}
} else {
l++;
}
i++;
+ if (l > PATH_MAX)
+ /* your expanded path length is ridiculous */
+ goto end;
}
j = ret = Xmalloc(l+1);
if (ret == NULL)
- return ret;
+ goto end;
i = name;
while (*i) {
if (*i == '%') {
@@ -372,6 +394,7 @@ TransFileName(Xim im, char *name)
}
}
*j = '\0';
+end:
Xfree(lcCompose);
return ret;
}