05/08: gnu: libxrender: Fix CVE-2016-{7949,7950}.

[Leo Famulari]

lfam pushed a commit to branch master
in repository guix.

commit 666d40193c1880b6b68387389fb69eda60a5c7ee
Author: Leo Famulari <address@hidden>
Date:   Wed Oct 5 13:25:09 2016 -0400

    gnu: libxrender: Fix CVE-2016-{7949,7950}.
    
    * gnu/packages/patches/libxrender-CVE-2016-7949.patch,
    gnu/packages/patches/libxrender-CVE-2016-7950.patch: New files.
    * gnu/local.mk (dist_patch_DATA): Add them.
    * gnu/packages/xorg.scm (libxrender)[replacement]: New field.
    (libxrender/fixed): New variable.
---
 gnu/local.mk                                       |    2 +
 .../patches/libxrender-CVE-2016-7949.patch         |   66 ++++++++++++++++++
 .../patches/libxrender-CVE-2016-7950.patch         |   73 ++++++++++++++++++++
 gnu/packages/xorg.scm                              |    9 +++
 4 files changed, 150 insertions(+)

diff --git a/gnu/local.mk b/gnu/local.mk
index 22d63a9..ec237d9 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -674,6 +674,8 @@ dist_patch_DATA =                                           
\
   %D%/packages/patches/libxfixes-CVE-2016-7944.patch           \
   %D%/packages/patches/libxi-CVE-2016-7945-CVE-2016-7946.patch \
   %D%/packages/patches/libxrandr-CVE-2016-7947-CVE-2016-7948.patch     \
+  %D%/packages/patches/libxrender-CVE-2016-7949.patch          \
+  %D%/packages/patches/libxrender-CVE-2016-7950.patch          \
   %D%/packages/patches/libxslt-generated-ids.patch             \
   %D%/packages/patches/lirc-localstatedir.patch                        \
   %D%/packages/patches/llvm-for-extempore.patch                        \
diff --git a/gnu/packages/patches/libxrender-CVE-2016-7949.patch 
b/gnu/packages/patches/libxrender-CVE-2016-7949.patch
new file mode 100644
index 0000000..3a2be4e
--- /dev/null
+++ b/gnu/packages/patches/libxrender-CVE-2016-7949.patch
@@ -0,0 +1,66 @@
+Fix CVE-2016-7949:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7949
+
+Patch copied from upstream source repository:
+
+https://cgit.freedesktop.org/xorg/lib/libXrender/commit/?id=9362c7ddd1af3b168953d0737877bc52d79c94f4
+
+From 9362c7ddd1af3b168953d0737877bc52d79c94f4 Mon Sep 17 00:00:00 2001
+From: Tobias Stoeckmann <address@hidden>
+Date: Sun, 25 Sep 2016 21:43:09 +0200
+Subject: [PATCH] Validate lengths while parsing server data.
+
+Individual lengths inside received server data can overflow
+the previously reserved memory.
+
+It is therefore important to validate every single length
+field to not overflow the previously agreed sum of all invidual
+length fields.
+
+v2: consume remaining bytes in the reply buffer on error.
+
+Signed-off-by: Tobias Stoeckmann <address@hidden>
+Reviewed-by: Matthieu address@hidden
+---
+ src/Xrender.c | 18 ++++++++++++++++++
+ 1 file changed, 18 insertions(+)
+
+diff --git a/src/Xrender.c b/src/Xrender.c
+index 3102eb2..71cf3e6 100644
+--- a/src/Xrender.c
++++ b/src/Xrender.c
+@@ -533,12 +533,30 @@ XRenderQueryFormats (Display *dpy)
+       screen->fallback = _XRenderFindFormat (xri, xScreen->fallback);
+       screen->subpixel = SubPixelUnknown;
+       xDepth = (xPictDepth *) (xScreen + 1);
++      if (screen->ndepths > rep.numDepths) {
++          Xfree (xri);
++          Xfree (xData);
++          _XEatDataWords (dpy, rep.length);
++          UnlockDisplay (dpy);
++          SyncHandle ();
++          return 0;
++      }
++      rep.numDepths -= screen->ndepths;
+       for (nd = 0; nd < screen->ndepths; nd++)
+       {
+           depth->depth = xDepth->depth;
+           depth->nvisuals = xDepth->nPictVisuals;
+           depth->visuals = visual;
+           xVisual = (xPictVisual *) (xDepth + 1);
++          if (depth->nvisuals > rep.numVisuals) {
++              Xfree (xri);
++              Xfree (xData);
++              _XEatDataWords (dpy, rep.length);
++              UnlockDisplay (dpy);
++              SyncHandle ();
++              return 0;
++          }
++          rep.numVisuals -= depth->nvisuals;
+           for (nv = 0; nv < depth->nvisuals; nv++)
+           {
+               visual->visual = _XRenderFindVisual (dpy, xVisual->visual);
+-- 
+2.10.1
+
diff --git a/gnu/packages/patches/libxrender-CVE-2016-7950.patch 
b/gnu/packages/patches/libxrender-CVE-2016-7950.patch
new file mode 100644
index 0000000..1a64b6e
--- /dev/null
+++ b/gnu/packages/patches/libxrender-CVE-2016-7950.patch
@@ -0,0 +1,73 @@
+Fix CVE-2016-7950:
+
+https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-7950
+
+Patch copied from upstream source repository:
+
+https://cgit.freedesktop.org/xorg/lib/libXrender/commit/?id=8fad00b0b647ee662ce4737ca15be033b7a21714
+
+From 8fad00b0b647ee662ce4737ca15be033b7a21714 Mon Sep 17 00:00:00 2001
+From: Tobias Stoeckmann <address@hidden>
+Date: Sun, 25 Sep 2016 21:42:09 +0200
+Subject: [PATCH] Avoid OOB write in XRenderQueryFilters
+
+The memory for filter names is reserved right after receiving the reply.
+After that, filters are iterated and each individual filter name is
+stored in that reserved memory.
+
+The individual name lengths are not checked for validity, which means
+that a malicious server can reserve less memory than it will write to
+during each iteration.
+
+v2: consume remaining bytes in reply buffer on error.
+
+Signed-off-by: Tobias Stoeckmann <address@hidden>
+Reviewed-by: Matthieu Herrb <address@hidden>
+---
+ src/Filter.c | 13 ++++++++++++-
+ 1 file changed, 12 insertions(+), 1 deletion(-)
+
+diff --git a/src/Filter.c b/src/Filter.c
+index edfa572..8d701eb 100644
+--- a/src/Filter.c
++++ b/src/Filter.c
+@@ -38,7 +38,7 @@ XRenderQueryFilters (Display *dpy, Drawable drawable)
+     char                      *name;
+     char                      len;
+     int                               i;
+-    unsigned long             nbytes, nbytesAlias, nbytesName;
++    unsigned long             nbytes, nbytesAlias, nbytesName, reply_left;
+ 
+     if (!RenderHasExtension (info))
+       return NULL;
+@@ -114,6 +114,7 @@ XRenderQueryFilters (Display *dpy, Drawable drawable)
+      * Read the filter aliases
+      */
+     _XRead16Pad (dpy, filters->alias, 2 * rep.numAliases);
++    reply_left = 8 + rep.length - 2 * rep.numAliases;;
+ 
+     /*
+      * Read the filter names
+@@ -122,9 +123,19 @@ XRenderQueryFilters (Display *dpy, Drawable drawable)
+     {
+       int     l;
+       _XRead (dpy, &len, 1);
++      reply_left--;
+       l = len & 0xff;
++      if ((unsigned long)l + 1 > nbytesName) {
++            _XEatDataWords(dpy, reply_left);
++          Xfree(filters);
++          UnlockDisplay (dpy);
++          SyncHandle ();
++          return NULL;
++      }
++      nbytesName -= l + 1;
+       filters->filter[i] = name;
+       _XRead (dpy, name, l);
++        reply_left -= l;
+       name[l] = '\0';
+       name += l + 1;
+     }
+-- 
+2.10.1
+
diff --git a/gnu/packages/xorg.scm b/gnu/packages/xorg.scm
index b6cfbd6..2df6631 100644
--- a/gnu/packages/xorg.scm
+++ b/gnu/packages/xorg.scm
@@ -4602,6 +4602,7 @@ cannot be adequately worked around on the client side of 
the wire.")
 (define-public libxrender
   (package
     (name "libxrender")
+    (replacement libxrender/fixed)
     (version "0.9.9")
     (source
       (origin
@@ -4626,6 +4627,14 @@ cannot be adequately worked around on the client side of 
the wire.")
     (description "Library for the Render Extension to the X11 protocol.")
     (license license:x11)))
 
+(define libxrender/fixed
+  (package
+    (inherit libxrender)
+    (source (origin
+              (inherit (package-source libxrender))
+              (patches (search-patches
+                         "libxrender-CVE-2016-7949.patch"
+                         "libxrender-CVE-2016-7950.patch"))))))
 
 (define-public libxtst
   (package