From e2aec8c91e9d6ed3fc76f9f145dec8a456ce623a Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Fri, 24 Jun 2022 17:53:34 -0500
Subject: [PATCH] grep: fix regex compilation memory leaks

Problem reported by Jim Meyering in:
https://lists.gnu.org/r/grep-devel/2022-06/msg00012.html
* src/dfasearch.c (regex_compile): Fix memory leaks when SYNTAX_ONLY.

Reference:https://git.savannah.gnu.org/cgit/grep.git/commit?id=e2aec8c91e9d6ed3fc76f9f145dec8a456ce623a
Conflict:context adaptation
---
 src/dfasearch.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/dfasearch.c b/src/dfasearch.c
index d6afa8d..2875453 100644
--- a/src/dfasearch.c
+++ b/src/dfasearch.c
@@ -148,24 +148,32 @@ regex_compile (struct dfa_comp *dc, char const *p, ptrdiff_t len,
                ptrdiff_t pcount, ptrdiff_t lineno, reg_syntax_t syntax_bits,
                bool syntax_only)
 {
-  struct re_pattern_buffer pat0;
-  struct re_pattern_buffer *pat = syntax_only ? &pat0 : &dc->patterns[pcount];
-  pat->buffer = NULL;
-  pat->allocated = 0;
+  struct re_pattern_buffer pat;
+  pat.buffer = NULL;
+  pat.allocated = 0;
 
   /* Do not use a fastmap with -i, to work around glibc Bug#20381.  */
-  pat->fastmap = (syntax_only | match_icase) ? NULL : xmalloc (UCHAR_MAX + 1);
+  pat.fastmap = syntax_only | match_icase ? NULL : ximalloc (UCHAR_MAX + 1);
 
-  pat->translate = NULL;
+  pat.translate = NULL;
 
   if (syntax_only)
     re_set_syntax (syntax_bits | RE_NO_SUB);
   else
     re_set_syntax (syntax_bits);
 
-  char const *err = re_compile_pattern (p, len, pat);
+  char const *err = re_compile_pattern (p, len, &pat);
   if (!err)
-    return true;
+    {
+      if (syntax_only)
+        regfree (&pat);
+      else
+        dc->patterns[pcount] = pat;
+
+      return true;
+    }
+
+  free (pat.fastmap);
 
   /* Emit a filename:lineno: prefix for patterns taken from files.  */
   size_t pat_lineno;
-- 
2.27.0

