gnu: grep: Apply fix for CVE-2015-1345.

* gnu/packages/patches/grep-CVE-2015-1345.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/base.scm (grep): Add patch.

gnu-system.am

@@ -398,6 +398,7 @@ dist_patch_DATA =						\
   gnu/packages/patches/gobject-introspection-absolute-shlib-path.patch \
   gnu/packages/patches/gobject-introspection-cc.patch		\
   gnu/packages/patches/gobject-introspection-girepository.patch	\
+  gnu/packages/patches/grep-CVE-2015-1345.patch			\
   gnu/packages/patches/grub-gets-undeclared.patch		\
   gnu/packages/patches/gstreamer-0.10-bison3.patch		\
   gnu/packages/patches/gstreamer-0.10-silly-test.patch		\

gnu/packages/base.scm

@@ -73,7 +73,8 @@ (define-public grep
                                 version ".tar.xz"))
             (sha256
              (base32
-              "1pp5n15qwxrw1pibwjhhgsibyv5cafhamf8lwzjygs6y00fa2i2j"))))
+              "1pp5n15qwxrw1pibwjhhgsibyv5cafhamf8lwzjygs6y00fa2i2j"))
+            (patches (list (search-patch "grep-CVE-2015-1345.patch")))))
    (build-system gnu-build-system)
    (synopsis "Print lines matching a pattern")
    (description

gnu/packages/patches/grep-CVE-2015-1345.patch

+Fix CVE-2015-1345.  From upstream commit
+83a95bd8c8561875b948cadd417c653dbe7ef2e2
+by Yuliy Pisetsky <ypisetsky@fb.com>.
+
+diff --git a/src/kwset.c b/src/kwset.c
+index 4003c8d..376f7c3 100644
+--- a/src/kwset.c
++++ b/src/kwset.c
+@@ -643,6 +643,8 @@ bmexec_trans (kwset_t kwset, char const *text, size_t size)
+                     if (! tp)
+                       return -1;
+                     tp++;
++                    if (ep <= tp)
++                      break;
+                   }
+               }
+           }