Re: [PATCH] [v3] hfs: fix a memleak in hfs_find_init

[Viacheslav Dubeyko]

> On Feb 7, 2024, at 3:12 PM, Zhipeng Lu <alexious@xxxxxxxxxx> wrote:
> 
> If hfs_find_init succeeds but some other function called after it fails,
> the overall cleanup function of hfs_find_init (i.e. hfs_find_exit) will
> be called and `fd->search_key` is freed. However, if hfs_find_init fails
> and returns an error, neither external nor internal deallocation of
> `fd->search_key` is triggered.
> 
> This observation suggests that there could be a memleak problem in
> hfs_find_init. In this patch, we add the missing deallocation in the
> error-handling path (i.e. the default branch of the switch statement) to
> prevent such memory leak.
> 
> Fixes: b3b2177a2d79 ("hfs: add lock nesting notation to hfs_find_init")
> Signed-off-by: Zhipeng Lu <alexious@xxxxxxxxxx>
> ---
> Changelog:
> 
> v2: Improve commit message to be more clear.
> v3: Update commit message.

Looks good. Thanks a lot for reworking the comment section.

Reviewed-by: Viacheslav Dubeyko <slava@xxxxxxxxxxx>

Thanks,
Slava.

> ---
> fs/hfs/bfind.c | 1 +
> 1 file changed, 1 insertion(+)
> 
> 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;
> -- 
> 2.34.1
>