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[PATCH v2] Fix buffer overflow in git-grep

From
Dmitry Potapov <dpotapov@gmail.com>
Date
Jul 16, 2008, 15:33 UTC
Message-ID
<1216222409-31785-1-git-send-email-dpotapov@gmail.com>
In-Reply-To
<alpine.DEB.1.00.0807161232110.8503@eeepc-johanness>

If PATH_MAX on your system is smaller than any path stored in the git repository, that can cause memory corruption inside of the grep_tree function used by git-grep.

Signed-off-by: Dmitry Potapov <dpotapov@gmail.com>
---
I have converted grep_tree code to use path_buf.
 builtin-grep.c |   26 ++++++++++++++------------
 1 files changed, 14 insertions(+), 12 deletions(-)
diff --git a/builtin-grep.c b/builtin-grep.c
index ef29910..507bb95 100644
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -427,33 +427,35 @@ static int grep_tree(struct grep_opt *opt, const char **paths,
 	struct name_entry entry;
 	char *down;
 	int tn_len = strlen(tree_name);
-	char *path_buf = xmalloc(PATH_MAX + tn_len + 100);
+	struct strbuf pathbuf;
+
+	strbuf_init(&pathbuf, PATH_MAX + tn_len);
 
 	if (tn_len) {
-		tn_len = sprintf(path_buf, "%s:", tree_name);
-		down = path_buf + tn_len;
-		strcat(down, base);
-	}
-	else {
-		down = path_buf;
-		strcpy(down, base);
+		strbuf_add(&pathbuf, tree_name, tn_len);
+		strbuf_addch(&pathbuf, ':');
+		tn_len = pathbuf.len;
 	}
-	len = strlen(path_buf);
+	strbuf_addstr(&pathbuf, base);
+	len = pathbuf.len;
 
 	while (tree_entry(tree, &entry)) {
-		strcpy(path_buf + len, entry.path);
+		int te_len = tree_entry_len(entry.path, entry.sha1);
+		pathbuf.len = len;
+		strbuf_add(&pathbuf, entry.path, te_len);
 
 		if (S_ISDIR(entry.mode))
 			/* Match "abc/" against pathspec to
 			 * decide if we want to descend into "abc"
 			 * directory.
 			 */
-			strcpy(path_buf + len + tree_entry_len(entry.path, entry.sha1), "/");
+			strbuf_addch(&pathbuf, '/');
 
+		down = pathbuf.buf + tn_len;
 		if (!pathspec_matches(paths, down))
 			;
 		else if (S_ISREG(entry.mode))
-			hit |= grep_sha1(opt, entry.sha1, path_buf, tn_len);
+			hit |= grep_sha1(opt, entry.sha1, pathbuf.buf, tn_len);
 		else if (S_ISDIR(entry.mode)) {
 			enum object_type type;
 			struct tree_desc sub;
-- 
1.5.6.3.1.g4e6bb
Previous: Dmitry Potapov
Message 10 of 10 in “Fix buffer overflow in git-grep”
  1. Fix buffer overflow in git-grepDmitry Potapov, Jul 16, 2008
  2. Johannes SchindelinJul 16, 2008
  3. Dmitry PotapovJul 16, 2008
  4. Dmitry PotapovJul 16, 2008
  5. Johannes SchindelinJul 16, 2008
  6. Fix buffer overflow in git diffDmitry Potapov, Jul 16, 2008
  7. Fix buffer overflow in prepare_attr_stackDmitry Potapov, Jul 16, 2008
  8. Johannes SixtJul 16, 2008
  9. Fix buffer overflow in prepare_attr_stackDmitry Potapov, Jul 16, 2008
  10. Fix buffer overflow in git-grepDmitry Potapov, Jul 16, 2008

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