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[PATCH 5/8] git-config: fix regexp memory leaks on error conditions

From
Jeff King <peff@peff.net>
Date
Oct 23, 2012, 22:38 UTC
Message-ID
<20121023223855.GE17392@sigill.intra.peff.net>
In-Reply-To
<20121023223502.GA23194@sigill.intra.peff.net>

The get_value function has a goto label for cleaning up on errors, but it only cleans up half of what the function might allocate. Let's also clean up the key and regexp variables there.

Note that we need to take special care when compiling the regex fails to clean it up ourselves, since it is in a half-constructed state (we would want to free it, but not regfree it).

Similarly, we fix git_config_parse_key to return NULL when it fails, not a pointer to some already-freed memory.

Signed-off-by: Jeff King <peff@peff.net>
---
The diff is annoying in an interesting way: what I actually did was move
the regex cleanup code down, but it shows it as moving the bottom bits
up. I think it is just one of those ambiguous cases where either way is
equally valid and minimal.
 builtin/config.c | 23 +++++++++++++----------
 config.c         |  1 +
 2 files changed, 14 insertions(+), 10 deletions(-)
diff --git a/builtin/config.c b/builtin/config.c
index e660d48..60d36e7 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -195,7 +195,8 @@ static int get_value(const char *key_, const char *regex_)
 		key_regexp = (regex_t*)xmalloc(sizeof(regex_t));
 		if (regcomp(key_regexp, key, REG_EXTENDED)) {
 			fprintf(stderr, "Invalid key pattern: %s\n", key_);
-			free(key);
+			free(key_regexp);
+			key_regexp = NULL;
 			ret = CONFIG_INVALID_PATTERN;
 			goto free_strings;
 		}
@@ -215,6 +216,8 @@ static int get_value(const char *key_, const char *regex_)
 		regexp = (regex_t*)xmalloc(sizeof(regex_t));
 		if (regcomp(regexp, regex_, REG_EXTENDED)) {
 			fprintf(stderr, "Invalid pattern: %s\n", regex_);
+			free(regexp);
+			regexp = NULL;
 			ret = CONFIG_INVALID_PATTERN;
 			goto free_strings;
 		}
@@ -247,6 +250,15 @@ static int get_value(const char *key_, const char *regex_)
 	if (!do_all && !seen && system_wide)
 		git_config_from_file(fn, system_wide, data);
 
+	if (do_all)
+		ret = !seen;
+	else
+		ret = (seen == 1) ? 0 : seen > 1 ? 2 : 1;
+
+free_strings:
+	free(repo_config);
+	free(global);
+	free(xdg);
 	free(key);
 	if (key_regexp) {
 		regfree(key_regexp);
@@ -257,15 +269,6 @@ static int get_value(const char *key_, const char *regex_)
 		free(regexp);
 	}
 
-	if (do_all)
-		ret = !seen;
-	else
-		ret = (seen == 1) ? 0 : seen > 1 ? 2 : 1;
-
-free_strings:
-	free(repo_config);
-	free(global);
-	free(xdg);
 	return ret;
 }
 
diff --git a/config.c b/config.c
index 08e47e2..2fbe634 100644
--- a/config.c
+++ b/config.c
@@ -1280,6 +1280,7 @@ out_free_ret_1:
 
 out_free_ret_1:
 	free(*store_key);
+	*store_key = NULL;
 	return -CONFIG_INVALID_KEY;
 }
 
-- 
1.8.0.3.g3456896
Previous: Jeff KingNext: Jeff King
Message 12 of 25 in “The config include mechanism doesn't allow for overwriting”
  1. Ævar Arnfjörð BjarmasonOct 22, 2012
  2. Jeff KingOct 22, 2012
  3. Ævar Arnfjörð BjarmasonOct 23, 2012
  4. 0/8 fix git-config with duplicate variable entriesJeff King, Oct 23, 2012
  5. 1/8 t1300: style updatesJeff King, Oct 23, 2012
  6. Johannes SixtOct 24, 2012
  7. Jeff KingOct 24, 2012
  8. 1/8 t1300: style updatesJeff King, Oct 24, 2012
  9. 2/8 t1300: remove redundant testJeff King, Oct 23, 2012
  10. 3/8 t1300: test "git config --get-all" more thoroughlyJeff King, Oct 23, 2012
  11. 4/8 git-config: remove memory leak of key regexpJeff King, Oct 23, 2012
  12. 5/8 git-config: fix regexp memory leaks on error conditionsJeff King, Oct 23, 2012
  13. 6/8 git-config: collect values instead of immediately printingJeff King, Oct 23, 2012
  14. 7/8 git-config: do not complain about duplicate entriesJeff King, Oct 23, 2012
  15. 8/8 git-config: use git_config_with_optionsJeff King, Oct 23, 2012
  16. Johannes SixtOct 24, 2012
  17. Ævar Arnfjörð BjarmasonOct 24, 2012
  18. Junio C HamanoNov 20, 2012
  19. Jeff KingNov 21, 2012
  20. Junio C HamanoNov 21, 2012
  21. Jeff KingNov 21, 2012
  22. Junio C HamanoNov 21, 2012
  23. Joachim SchmitzNov 23, 2012
  24. John SzakmeisterOct 24, 2012
  25. Jeff KingOct 24, 2012

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