grep branch, master, updated. v2.21-17-gfbc60d4

[Paul Eggert]

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http://git.savannah.gnu.org/cgit/grep.git/commit/?id=fbc60d437bcaa586801441677bb1dccc1f7077d8


commit fbc60d437bcaa586801441677bb1dccc1f7077d8
Author: Paul Eggert <address@hidden>
Date:   Tue Feb 10 23:44:36 2015 -0800

    Grow the JIT stack if it becomes exhausted
    
    Problem reported by Oliver Freyermuth in: http://bugs.gnu.org/19833
    * NEWS: Document the fix.
    * tests/Makefile.am (TESTS): Add pcre-jitstack.
    * tests/pcre-jitstack: New file.
    * src/pcresearch.c (NSUB): Move decl earlier, since it's needed
    earlier now.
    (jit_stack_size) [PCRE_STUDY_JIT_COMPILE]: New static var.
    (jit_exec): New function.
    (Pcompile): Initialize jit_stack_size.
    (Pexecute): Use new jit_exec function.  Report a useful diagnostic
    if the error is PCRE_ERROR_JIT_STACKLIMIT.

diff --git a/NEWS b/NEWS
index da8bc78..071caab 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,9 @@ GNU grep NEWS                                    -*- outline -*-
   grep no longer reads from uninitialized memory or from beyond the end
   of the heap-allocated input buffer.  This fix addressed CVE-2015-1345.
 
+  When the JIT stack is exhausted, grep -P now grows the stack rather
+  than reporting an internal PCRE error.
+
 
 * Noteworthy changes in release 2.21 (2014-11-23) [stable]
 
diff --git a/src/pcresearch.c b/src/pcresearch.c
index 0bd021a..afe4f2b 100644
--- a/src/pcresearch.c
+++ b/src/pcresearch.c
@@ -27,6 +27,11 @@
 #endif
 
 #if HAVE_LIBPCRE
+
+/* This must be at least 2; everything after that is for performance
+   in pcre_exec.  */
+enum { NSUB = 300 };
+
 /* Compiled internal form of a Perl regular expression.  */
 static pcre *cre;
 
@@ -36,6 +41,45 @@ static pcre_extra *extra;
 # ifndef PCRE_STUDY_JIT_COMPILE
 #  define PCRE_STUDY_JIT_COMPILE 0
 # endif
+
+# if PCRE_STUDY_JIT_COMPILE
+/* Maximum size of the JIT stack.  */
+static int jit_stack_size;
+# endif
+
+/* Match the already-compiled PCRE pattern against the data in P, of
+   size SEARCH_BYTES, with options OPTIONS, and storing resulting
+   matches into SUB.  Return the (nonnegative) match location or a
+   (negative) error number.  */
+static int
+jit_exec (char const *p, int search_bytes, int options, int *sub)
+{
+  while (true)
+    {
+      int e = pcre_exec (cre, extra, p, search_bytes, 0, options, sub, NSUB);
+
+# if PCRE_STUDY_JIT_COMPILE
+      if (e == PCRE_ERROR_JIT_STACKLIMIT
+          && 0 < jit_stack_size && jit_stack_size <= INT_MAX / 2)
+        {
+          int old_size = jit_stack_size;
+          int new_size = jit_stack_size = old_size * 2;
+          static pcre_jit_stack *jit_stack;
+          if (jit_stack)
+            pcre_jit_stack_free (jit_stack);
+          jit_stack = pcre_jit_stack_alloc (old_size, new_size);
+          if (!jit_stack)
+            error (EXIT_TROUBLE, 0,
+                   _("failed to allocate memory for the PCRE JIT stack"));
+          pcre_assign_jit_stack (extra, NULL, jit_stack);
+          continue;
+        }
+# endif
+
+      return e;
+    }
+}
+
 #endif
 
 #if HAVE_LIBPCRE
@@ -44,10 +88,6 @@ static pcre_extra *extra;
 static int empty_match[2];
 #endif
 
-/* This must be at least 2; everything after that is for performance
-   in pcre_exec.  */
-enum { NSUB = 300 };
-
 void
 Pcompile (char const *pattern, size_t size)
 {
@@ -121,19 +161,11 @@ Pcompile (char const *pattern, size_t size)
   if (pcre_fullinfo (cre, extra, PCRE_INFO_JIT, &e))
     error (EXIT_TROUBLE, 0, _("internal error (should never happen)"));
 
+  /* The PCRE documentation says that a 32 KiB stack is the default.  */
   if (e)
-    {
-      /* A 32K stack is allocated for the machine code by default, which
-         can grow to 512K if necessary. Since JIT uses far less memory
-         than the interpreter, this should be enough in practice.  */
-      pcre_jit_stack *jit_stack = pcre_jit_stack_alloc (32 * 1024, 512 * 1024);
-      if (!jit_stack)
-        error (EXIT_TROUBLE, 0,
-               _("failed to allocate memory for the PCRE JIT stack"));
-      pcre_assign_jit_stack (extra, NULL, jit_stack);
-    }
-
+    jit_stack_size = 32 << 10;
 # endif
+
   free (re);
 
   int sub[NSUB];
@@ -214,8 +246,7 @@ Pexecute (char const *buf, size_t size, size_t *match_size,
           if (multiline)
             options |= PCRE_NO_UTF8_CHECK;
 
-          e = pcre_exec (cre, extra, p, search_bytes, 0,
-                         options, sub, NSUB);
+          e = jit_exec (p, search_bytes, options, sub);
           if (e != PCRE_ERROR_BADUTF8)
             {
               if (0 < e && multiline && sub[1] - sub[0] != 0)
@@ -268,9 +299,13 @@ Pexecute (char const *buf, size_t size, size_t *match_size,
         case PCRE_ERROR_NOMEMORY:
           error (EXIT_TROUBLE, 0, _("memory exhausted"));
 
+# if PCRE_STUDY_JIT_COMPILE
+        case PCRE_ERROR_JIT_STACKLIMIT:
+          error (EXIT_TROUBLE, 0, _("PCRE JIT stack exhausted"));
+# endif
+
         case PCRE_ERROR_MATCHLIMIT:
-          error (EXIT_TROUBLE, 0,
-                 _("exceeded PCRE's backtracking limit"));
+          error (EXIT_TROUBLE, 0, _("exceeded PCRE's backtracking limit"));
 
         default:
           /* For now, we lump all remaining PCRE failures into this basket.
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 0508cd2..8fcf8f6 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -95,6 +95,7 @@ TESTS =                                               \
   pcre-abort                                   \
   pcre-infloop                                 \
   pcre-invalid-utf8-input                      \
+  pcre-jitstack                                        \
   pcre-o                                       \
   pcre-utf8                                    \
   pcre-w                                       \
diff --git a/tests/pcre-jitstack b/tests/pcre-jitstack
new file mode 100755
index 0000000..03587f1
--- /dev/null
+++ b/tests/pcre-jitstack
@@ -0,0 +1,39 @@
+#! /bin/sh
+# Grep 2.21 would report "grep: internal PCRE error: -27"
+#
+# Copyright 2015 Free Software Foundation, Inc.
+#
+# Copying and distribution of this file, with or without modification,
+# are permitted in any medium without royalty provided the copyright
+# notice and this notice are preserved.
+
+. "${srcdir=.}/init.sh"; path_prepend_ ../src
+require_pcre_
+
+nl_base64=$(echo | (base64) 2>/dev/null) && test "X$nl_base64" = XCg== ||
+  skip_ "your system lacks the base64 program"
+foo=$( (echo foo | gzip | gzip -d) 2>/dev/null) && test "X$foo" = Xfoo ||
+  skip_ "your system lacks the gzip program"
+
+fail=0
+
+base64 -d >pcrejit.txt.gz <<'EOF'
+H4sIAAAAAAACA+2bUU4DMQxE/7mMz5T7XwKE+IBKVLue58yk0B9EtX6xJxN7t4VaH69a6+tHrW+/
+r4e3n75KARWShSOFTtiumE3FPVyo79ATIJ0Ry0No/yXe99UIUqTGKKUzYHFJHJoaCONQDCnDSCDS
+IPAvGCVeXNsZ7lpbWFfdaZtgPos5LeK2C1TBKzD09V3HFlCOsbFT/hNbz4HzJaRjnjdam9FXw/o6
+VyPozhMmiaRYAMeNSJR1iMjBEFLMtsH7lptartfxkzPQgFVofwRlxKsMYn2KNDnU9fsOQCkRIYVT
+G80ZRqBpSQjRYPX7s9gvtqknyNE2f8V09sxHM7YPmMMJgrmVna2AT717n5fUAIDkiBCqFgWUUgKD
+8jOc0Rgj5JS6vZnQI14wkaTDAkD266p/iVHs8gjCrMFARVM0iEVgFAa9YRAQT4tkgsmloTJLmyCm
+uSHRnTkzIdZMmZ5kYX/iJFtTwu9cFvr3aDWcUx4pUW/cVQwPoQSlwguNd4M0vTpAauKodmLFXv1P
+dkcKkYUglER2Q4L4gnmOiNGzSBATwGQgwihs5/QffIhyfg4hJvM2r4Rp6L+1ibCCd4jYZ6jCiBlc
+2+y4fl4yTGIwcWXNAUEeXmu8iCMV96DNTnmRNICDk2N5qaXGbsF91OX/0hlcYTjrMfy02p9Xv70D
+mv3RZCFOAAA=
+EOF
+test $? -eq 0 || framework_failure_
+
+gzip -d pcrejit.txt || framework_failure_
+
+LC_ALL=C grep -P -n '^([/](?!/)|[^/])*~/.*' pcrejit.txt
+test $? -eq 1 || fail=1
+
+Exit $fail

-----------------------------------------------------------------------

Summary of changes:
 NEWS                |    3 ++
 src/pcresearch.c    |   73 +++++++++++++++++++++++++++++++++++++-------------
 tests/Makefile.am   |    1 +
 tests/pcre-jitstack |   39 +++++++++++++++++++++++++++
 4 files changed, 97 insertions(+), 19 deletions(-)
 create mode 100755 tests/pcre-jitstack


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