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Subject: Re: [PATCH] [v2] hfs: fix a memleak in hfs_find_init
From: Viacheslav Dubeyko <slava@dubeyko.com>
In-Reply-To: <20240201130027.3058006-1-alexious@zju.edu.cn>
Date: Fri, 2 Feb 2024 16:17:49 +0300
Cc: Desmond Cheong Zhi Xi <desmondcheongzx@gmail.com>,
 Andrew Morton <akpm@linux-foundation.org>,
 linux-fsdevel@vger.kernel.org,
 linux-kernel@vger.kernel.org
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Message-Id: <464B735B-EE9E-4AAC-8AA5-B746D707D69B@dubeyko.com>
References: <20240201130027.3058006-1-alexious@zju.edu.cn>
To: Zhipeng Lu <alexious@zju.edu.cn>


> On 1 Feb 2024, at 16:00, Zhipeng Lu <alexious@zju.edu.cn> wrote:
>=20
> In every caller of hfs_find_init, `ptr` won't be freed when =
hfs_find_init
> fails, but will be freed when somewhere after hfs_find_init fails.

Current statement sounds confusing for my taste. I don=E2=80=99t follow =
it.
What do you mean here?

> This suggests that hfs_find_init should proberly free `ptr` in its own
> error-handling to prevent `ptr` from leaking.

I assume you meant properly here?

>=20
> In particular, When the switch statment goes to default and return an =
error,
> `ptr` should be freed.

I assume you meant statement here?

Also, you mentioning `ptr` but we freed fd->search_key here. It sounds =
confusing too.

>=20
> Fixes: b3b2177a2d79 ("hfs: add lock nesting notation to =
hfs_find_init")
> Signed-off-by: Zhipeng Lu <alexious@zju.edu.cn>
> ---
> Changelog:
>=20
> v2: Improve commit message to be more clear.

Currently, it sounds slightly more confusing. :)

Thanks,
Slava.

> ---
> fs/hfs/bfind.c | 1 +
> 1 file changed, 1 insertion(+)
>=20
> diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c
> index ef9498a6e88a..7aa3b9aba4d1 100644
> --- a/fs/hfs/bfind.c
> +++ b/fs/hfs/bfind.c
> @@ -36,6 +36,7 @@ int hfs_find_init(struct hfs_btree *tree, struct =
hfs_find_data *fd)
> mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
> break;
> default:
> + kfree(fd->search_key);
> return -EINVAL;
> }
> return 0;
> --=20
> 2.34.1
>=20