gnu: aspell: Patch CVE-2019-25051.

* gnu/packages/aspell.scm (aspell)[source]: Add patch.
* gnu/packages/patches/aspell-CVE-2019-25051.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.

gnu/local.mk

@@ -861,6 +861,7 @@ dist_patch_DATA =						\
   %D%/packages/patches/aoflagger-use-system-provided-pybind11.patch \
   %D%/packages/patches/apr-skip-getservbyname-test.patch	\
   %D%/packages/patches/ark-skip-xar-test.patch			\
+  %D%/packages/patches/aspell-CVE-2019-25051.patch		\
   %D%/packages/patches/aspell-default-dict-dir.patch		\
   %D%/packages/patches/ath9k-htc-firmware-binutils.patch	\
   %D%/packages/patches/ath9k-htc-firmware-gcc.patch		\

gnu/packages/aspell.scm

@@ -55,7 +55,8 @@
       (sha256
        (base32
         "1wi60ankalmh8ds7nplz434jd7j94gdvbahdwsr539rlad8pxdzr"))
-      (patches (search-patches "aspell-default-dict-dir.patch"))))
+      (patches (search-patches "aspell-default-dict-dir.patch"
+                               "aspell-CVE-2019-25051.patch"))))
     (build-system gnu-build-system)
     (arguments
      `(#:phases

gnu/packages/patches/aspell-CVE-2019-25051.patch

@@ -0,0 +1,99 @@
+https://github.com/gnuaspell/aspell/commit/0718b375425aad8e54e1150313b862e4c6fd324a
+https://nvd.nist.gov/vuln/detail/CVE-2019-25051
+
+From 0718b375425aad8e54e1150313b862e4c6fd324a Mon Sep 17 00:00:00 2001
+From: Kevin Atkinson <kevina@gnu.org>
+Date: Sat, 21 Dec 2019 20:32:47 +0000
+Subject: [PATCH] objstack: assert that the alloc size will fit within a chunk
+ to prevent a buffer overflow
+
+Bug found using OSS-Fuze.
+---
+ common/objstack.hpp | 18 ++++++++++++++----
+ 1 file changed, 14 insertions(+), 4 deletions(-)
+
+diff --git a/common/objstack.hpp b/common/objstack.hpp
+index 3997bf7..bd97ccd 100644
+--- a/common/objstack.hpp
++++ b/common/objstack.hpp
+@@ -5,6 +5,7 @@
+ #include "parm_string.hpp"
+ #include <stdlib.h>
+ #include <assert.h>
++#include <stddef.h>
+ 
+ namespace acommon {
+ 
+@@ -26,6 +27,12 @@ class ObjStack
+   byte * temp_end;
+   void setup_chunk();
+   void new_chunk();
++  bool will_overflow(size_t sz) const {
++    return offsetof(Node,data) + sz > chunk_size;
++  }
++  void check_size(size_t sz) {
++    assert(!will_overflow(sz));
++  }
+ 
+   ObjStack(const ObjStack &);
+   void operator=(const ObjStack &);
+@@ -56,7 +63,7 @@ class ObjStack
+   void * alloc_bottom(size_t size)  {
+     byte * tmp = bottom;
+     bottom += size;
+-    if (bottom > top) {new_chunk(); tmp = bottom; bottom += size;}
++    if (bottom > top) {check_size(size); new_chunk(); tmp = bottom; bottom += size;}
+     return tmp;
+   }
+   // This alloc_bottom will insure that the object is aligned based on the
+@@ -66,7 +73,7 @@ class ObjStack
+     align_bottom(align);
+     byte * tmp = bottom;
+     bottom += size;
+-    if (bottom > top) {new_chunk(); goto loop;}
++    if (bottom > top) {check_size(size); new_chunk(); goto loop;}
+     return tmp;
+   }
+   char * dup_bottom(ParmString str) {
+@@ -79,7 +86,7 @@ class ObjStack
+   // always be aligned as such.
+   void * alloc_top(size_t size) {
+     top -= size;
+-    if (top < bottom) {new_chunk(); top -= size;}
++    if (top < bottom) {check_size(size); new_chunk(); top -= size;}
+     return top;
+   }
+   // This alloc_top will insure that the object is aligned based on
+@@ -88,7 +95,7 @@ class ObjStack
+   {loop:
+     top -= size;
+     align_top(align);
+-    if (top < bottom) {new_chunk(); goto loop;}
++    if (top < bottom) {check_size(size); new_chunk(); goto loop;}
+     return top;
+   }
+   char * dup_top(ParmString str) {
+@@ -117,6 +124,7 @@ class ObjStack
+   void * alloc_temp(size_t size) {
+     temp_end = bottom + size;
+     if (temp_end > top) {
++      check_size(size);
+       new_chunk();
+       temp_end = bottom + size;
+     }
+@@ -131,6 +139,7 @@ class ObjStack
+     } else {
+       size_t s = temp_end - bottom;
+       byte * p = bottom;
++      check_size(size);
+       new_chunk();
+       memcpy(bottom, p, s);
+       temp_end = bottom + size;
+@@ -150,6 +159,7 @@ class ObjStack
+     } else {
+       size_t s = temp_end - bottom;
+       byte * p = bottom;
++      check_size(size);
+       new_chunk();
+       memcpy(bottom, p, s);
+       temp_end = bottom + size;