[PATCH] reftable/writer: fix memory leak when `padded_write()` fails

From: Lidong Yan via GitGitGadget <gitgitgadget@gmail.com>
Date: May 10, 2025, 03:50 UTC
Message-ID: <pull.1958.git.git.1746849030749.gitgitgadget@gmail.com>

From: Lidong Yan <502024330056@smail.nju.edu.cn>

In reftable/writer.c:padded_write(), if w->writer failed, zeroed allocated in `reftable_calloc` will leak. w->writer could be `reftable_write_data` in reftable/stack.c, and could fail due to some write error. Simply add reftable_free(zeroed) will solve this problem.

Signed-off-by: Lidong Yan <502024330056@smail.nju.edu.cn>
---
    reftable/writer: fix memory leak when padded_write() fails
    
    In reftable/writer.c:padded_write(), if w->writer failed, zeroed
    allocated in reftable_calloc will leak. w->writer could be
    reftable_write_data in reftable/stack.c, and could fail due to some
    write error. Simply add reftable_free(zeroed) will solve this problem.

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-1958%2Fbrandb97%2Ffix-reftable-padded-write-leak-v1
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-1958/brandb97/fix-reftable-padded-write-leak-v1
Pull-Request: https://github.com/git/git/pull/1958

 reftable/writer.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/reftable/writer.c b/reftable/writer.c
index cb16f71be49..3ceb3742888 100644
--- a/reftable/writer.c
+++ b/reftable/writer.c
@@ -57,8 +57,10 @@ static int padded_write(struct reftable_writer *w, uint8_t *data, size_t len,
 			return -1;
 
 		n = w->write(w->write_arg, zeroed, w->pending_padding);
-		if (n < 0)
+		if (n < 0) {
+			reftable_free(zeroed);
 			return n;
+		}
 
 		w->pending_padding = 0;
 		reftable_free(zeroed);

base-commit: 6f84262c44a89851c3ae5a6e4c1a9d06b2068d75

-- 
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