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 <[email protected]>
---
Changelog:
v2: Improve commit message to be more clear.
v3: Update commit message.
---
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
> On Feb 7, 2024, at 3:12 PM, Zhipeng Lu <[email protected]> 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 <[email protected]>
> ---
> 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 <[email protected]>
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
>