Subject: Re: [PATCH] fmt-merge-msg: plug small leak of commit buffer

From: Junio C Hamano <[email-masked]>
Date: Wed, 15 Apr 2015 14:30:17 -0700

Junio C Hamano <[email-masked]> writes:

> A broken or badly formatted commit might not record author or
> committer lines; the function record_person() returned after
> calling get_commit_buffer() without calling unuse_commit_buffer()
> on the memory, potentially leaking it.
>
> Signed-off-by: Junio C Hamano <[email-masked]>
> ---
>
>  * to be applied on bc6b8fc1 (use get_commit_buffer everywhere,
>    2014-06-10)

I spoke too soon.  There are two error-exit paths in this function.

-- >8 --
A broken or badly formatted commit might not record author or
committer lines or we may not find a valid name on them.  The
function record_person() returned after calling get_commit_buffer()
without calling unuse_commit_buffer() on the memory it obtained in
such cases, potentially leaking it.

Signed-off-by: Junio C Hamano <[email-masked]>
---
 builtin/fmt-merge-msg.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 01f6d59..76277d1 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -239,7 +239,7 @@ static void record_person(int which, struct string_list *people,
 	buffer = get_commit_buffer(commit);
 	name = strstr(buffer, field);
 	if (!name)
-		return;
+		goto leave;
 	name += strlen(field);
 	name_end = strchrnul(name, '<');
 	if (*name_end)
@@ -247,9 +247,8 @@ static void record_person(int which, struct string_list *people,
 	while (isspace(*name_end) && name <= name_end)
 		name_end--;
 	if (name_end < name)
-		return;
+		goto leave;
 	name_buf = xmemdupz(name, name_end - name + 1);
-	unuse_commit_buffer(commit, buffer);
 
 	elem = string_list_lookup(people, name_buf);
 	if (!elem) {
@@ -258,6 +257,8 @@ static void record_person(int which, struct string_list *people,
 	}
 	elem->util = (void*)(util_as_integral(elem) + 1);
 	free(name_buf);
+leave:
+	unuse_commit_buffer(commit, buffer);
 }
 
 static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
-- 
2.4.0-rc2-173-gefc434b