[linux-next] ecryptfs: crypto: use strscpy() to instead of strncpy()
Commit Message
From: Xu Panda <xu.panda@zte.com.cn>
The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL-terminated strings.
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
---
fs/ecryptfs/crypto.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
Comments
On Wed, Dec 28, 2022 at 09:36:54AM +0800, yang.yang29@zte.com.cn wrote:
> From: Xu Panda <xu.panda@zte.com.cn>
>
> The implementation of strscpy() is more robust and safer.
> That's now the recommended way to copy NUL-terminated strings.
Unlike strncpy(), strscpy() does not initialize the full destination array, so
it is unsafe in some situations, such as initializing structures that are then
copied to userspace or to disk. Please include an actual explanation for why
this patch is correct.
- Eric
@@ -1630,9 +1630,8 @@ ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
goto out;
}
mutex_init(&tmp_tfm->key_tfm_mutex);
- strncpy(tmp_tfm->cipher_name, cipher_name,
- ECRYPTFS_MAX_CIPHER_NAME_SIZE);
- tmp_tfm->cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE] = '\0';
+ strscpy(tmp_tfm->cipher_name, cipher_name,
+ ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1);
tmp_tfm->key_size = key_size;
rc = ecryptfs_process_key_cipher(&tmp_tfm->key_tfm,
tmp_tfm->cipher_name,