gnugrep: fix CVE-2015-1345 by upstream patch

pkgs/tools/text/gnugrep/cve-2015-1345.patch

@@ -0,0 +1,60 @@
+From 83a95bd8c8561875b948cadd417c653dbe7ef2e2 Mon Sep 17 00:00:00 2001
+From: Yuliy Pisetsky <ypisetsky@fb.com>
+Date: Thu, 01 Jan 2015 23:36:55 +0000
+Subject: grep -F: fix a heap buffer (read) overrun
+
+grep's read buffer is often filled to its full size, except when
+reading the final buffer of a file.  In that case, the number of
+bytes read may be far less than the size of the buffer.  However, for
+certain unusual pattern/text combinations, grep -F would mistakenly
+examine bytes in that uninitialized region of memory when searching
+for a match.  With carefully chosen inputs, one can cause grep -F to
+read beyond the end of that buffer altogether.  This problem arose via
+commit v2.18-90-g73893ff with the introduction of a more efficient
+heuristic using what is now the memchr_kwset function. The use of
+that function in bmexec_trans could leave TP much larger than EP,
+and the subsequent call to bm_delta2_search would mistakenly access
+beyond end of the main input read buffer.
+
+* src/kwset.c (bmexec_trans): When TP reaches or exceeds EP,
+do not call bm_delta2_search.
+* tests/kwset-abuse: New file.
+* tests/Makefile.am (TESTS): Add it.
+* THANKS.in: Update.
+* NEWS (Bug fixes): Mention it.
+
+Prior to this patch, this command would trigger a UMR:
+
+  printf %0360db 0 | valgrind src/grep -F $(printf %019dXb 0)
+
+  Use of uninitialised value of size 8
+     at 0x4142BE: bmexec_trans (kwset.c:657)
+     by 0x4143CA: bmexec (kwset.c:678)
+     by 0x414973: kwsexec (kwset.c:848)
+     by 0x414DC4: Fexecute (kwsearch.c:128)
+     by 0x404E2E: grepbuf (grep.c:1238)
+     by 0x4054BF: grep (grep.c:1417)
+     by 0x405CEB: grepdesc (grep.c:1645)
+     by 0x405EC1: grep_command_line_arg (grep.c:1692)
+     by 0x4077D4: main (grep.c:2570)
+
+See the accompanying test for how to trigger the heap buffer overrun.
+
+Thanks to Nima Aghdaii for testing and finding numerous
+ways to break early iterations of this patch.
+
+Nix: @vcunat restricted this to the runtime code only to avoid needing autoreconfiguration.
+---
+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;
+                   }
+               }
+           }

pkgs/tools/text/gnugrep/default.nix

@@ -10,6 +10,8 @@ stdenv.mkDerivation {
     sha256 = "1pp5n15qwxrw1pibwjhhgsibyv5cafhamf8lwzjygs6y00fa2i2j";
   };
 
+  patches = [ ./cve-2015-1345.patch ];
+
   buildInputs = [ pcre libiconv ];
 
   doCheck = !stdenv.isDarwin;