[OE-core] [PATCH][morty 2/2] libx11: CVE-2016-7943
Sona Sarmadi
sona.sarmadi at enea.com
Mon Jan 30 11:46:23 UTC 2017
The XListFonts function in X.org libX11 before 1.6.4 might allow
remote X servers to gain privileges via vectors involving length
fields, which trigger out-of-bounds write operations.
References:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7943
https://lists.x.org/archives/xorg-announce/2016-October/002720.html
Upstream patch:
https://cgit.freedesktop.org/xorg/lib/libX11/commit/?id=8c29f1607a31dac0911e45a0dd3d74173822b3c9
Signed-off-by: Sona Sarmadi <sona.sarmadi at enea.com>
---
.../xorg-lib/libx11/CVE-2016-7943.patch | 103 +++++++++++++++++++++
meta/recipes-graphics/xorg-lib/libx11_1.6.3.bb | 1 +
2 files changed, 104 insertions(+)
create mode 100644 meta/recipes-graphics/xorg-lib/libx11/CVE-2016-7943.patch
diff --git a/meta/recipes-graphics/xorg-lib/libx11/CVE-2016-7943.patch b/meta/recipes-graphics/xorg-lib/libx11/CVE-2016-7943.patch
new file mode 100644
index 0000000..5002423
--- /dev/null
+++ b/meta/recipes-graphics/xorg-lib/libx11/CVE-2016-7943.patch
@@ -0,0 +1,103 @@
+From 8c29f1607a31dac0911e45a0dd3d74173822b3c9 Mon Sep 17 00:00:00 2001
+From: Tobias Stoeckmann <tobias at stoeckmann.org>
+Date: Sun, 25 Sep 2016 21:22:57 +0200
+Subject: The validation of server responses avoids out of boundary accesses.
+
+v2: FontNames.c return a NULL list whenever a single
+length field from the server is incohent.
+
+CVE: CVE-2016-7943
+Upstream-Status: Backport
+
+Signed-off-by: Tobias Stoeckmann <tobias at stoeckmann.org>
+Reviewed-by: Matthieu Herrb <matthieu at herrb.eu>
+Signed-off-by: Sona Sarmadi <sona.sarmadi at enea.com>
+
+diff --git a/src/FontNames.c b/src/FontNames.c
+index 21dcafe..e55f338 100644
+--- a/src/FontNames.c
++++ b/src/FontNames.c
+@@ -66,7 +66,7 @@ int *actualCount) /* RETURN */
+
+ if (rep.nFonts) {
+ flist = Xmalloc (rep.nFonts * sizeof(char *));
+- if (rep.length < (INT_MAX >> 2)) {
++ if (rep.length > 0 && rep.length < (INT_MAX >> 2)) {
+ rlen = rep.length << 2;
+ ch = Xmalloc(rlen + 1);
+ /* +1 to leave room for last null-terminator */
+@@ -93,11 +93,22 @@ int *actualCount) /* RETURN */
+ if (ch + length < chend) {
+ flist[i] = ch + 1; /* skip over length */
+ ch += length + 1; /* find next length ... */
+- length = *(unsigned char *)ch;
+- *ch = '\0'; /* and replace with null-termination */
+- count++;
+- } else
+- flist[i] = NULL;
++ if (ch <= chend) {
++ length = *(unsigned char *)ch;
++ *ch = '\0'; /* and replace with null-termination */
++ count++;
++ } else {
++ Xfree(flist);
++ flist = NULL;
++ count = 0;
++ break;
++ }
++ } else {
++ Xfree(flist);
++ flist = NULL;
++ count = 0;
++ break;
++ }
+ }
+ }
+ *actualCount = count;
+diff --git a/src/ListExt.c b/src/ListExt.c
+index be6b989..0516e45 100644
+--- a/src/ListExt.c
++++ b/src/ListExt.c
+@@ -55,7 +55,7 @@ char **XListExtensions(
+
+ if (rep.nExtensions) {
+ list = Xmalloc (rep.nExtensions * sizeof (char *));
+- if (rep.length < (INT_MAX >> 2)) {
++ if (rep.length > 0 && rep.length < (INT_MAX >> 2)) {
+ rlen = rep.length << 2;
+ ch = Xmalloc (rlen + 1);
+ /* +1 to leave room for last null-terminator */
+@@ -80,9 +80,13 @@ char **XListExtensions(
+ if (ch + length < chend) {
+ list[i] = ch+1; /* skip over length */
+ ch += length + 1; /* find next length ... */
+- length = *ch;
+- *ch = '\0'; /* and replace with null-termination */
+- count++;
++ if (ch <= chend) {
++ length = *ch;
++ *ch = '\0'; /* and replace with null-termination */
++ count++;
++ } else {
++ list[i] = NULL;
++ }
+ } else
+ list[i] = NULL;
+ }
+diff --git a/src/ModMap.c b/src/ModMap.c
+index a809aa2..49a5d08 100644
+--- a/src/ModMap.c
++++ b/src/ModMap.c
+@@ -42,7 +42,8 @@ XGetModifierMapping(register Display *dpy)
+ GetEmptyReq(GetModifierMapping, req);
+ (void) _XReply (dpy, (xReply *)&rep, 0, xFalse);
+
+- if (rep.length < (INT_MAX >> 2)) {
++ if (rep.length < (INT_MAX >> 2) &&
++ (rep.length >> 1) == rep.numKeyPerModifier) {
+ nbytes = (unsigned long)rep.length << 2;
+ res = Xmalloc(sizeof (XModifierKeymap));
+ if (res)
+--
+cgit v0.10.2
+
diff --git a/meta/recipes-graphics/xorg-lib/libx11_1.6.3.bb b/meta/recipes-graphics/xorg-lib/libx11_1.6.3.bb
index 152ccd9..23a7789 100644
--- a/meta/recipes-graphics/xorg-lib/libx11_1.6.3.bb
+++ b/meta/recipes-graphics/xorg-lib/libx11_1.6.3.bb
@@ -6,6 +6,7 @@ BBCLASSEXTEND = "native nativesdk"
SRC_URI += "file://disable_tests.patch \
file://libX11-Add-missing-NULL-check.patch \
file://CVE-2016-7942.patch \
+ file://CVE-2016-7943.patch \
"
SRC_URI[md5sum] = "2e36b73f8a42143142dda8129f02e4e0"
--
1.9.1
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