Re: [PATCH] crypto: x86/aesni - Update aesni_set_key() to return void

Chang S. Bae
2024-03-12T15:03:54Z

On 3/12/2024 12:46 AM, Ard Biesheuvel wrote:
> On Mon, 11 Mar 2024 at 22:48, Chang S. Bae <chang.seok.bae@intel.com> wrote:
>>
>> @@ -241,7 +241,7 @@ static int aes_set_key_common(struct crypto_aes_ctx *ctx,
>> err = aes_expandkey(ctx, in_key, key_len);
>> else {
>> kernel_fpu_begin();
>> - err = aesni_set_key(ctx, in_key, key_len);
>> + aesni_set_key(ctx, in_key, key_len);
>
> This will leave 'err' uninitialized.

Ah, right. Thanks for catching it.

Also, upon reviewing aes_expandkey(), I noticed there's no error case,
except for the key length sanity check.

While addressing this, perhaps additional cleanup is considerable like:

@@ -233,19 +233,20 @@ static int aes_set_key_common(struct
crypto_aes_ctx *ctx,
{
int err;

- if (key_len != AES_KEYSIZE_128 && key_len != AES_KEYSIZE_192 &&
- key_len != AES_KEYSIZE_256)
- return -EINVAL;
+ err = aes_check_keylen(key_len);
+ if (err)
+ return err;

if (!crypto_simd_usable())
- err = aes_expandkey(ctx, in_key, key_len);
+ /* no error with a valid key length */
+ aes_expandkey(ctx, in_key, key_len);
else {
kernel_fpu_begin();
- err = aesni_set_key(ctx, in_key, key_len);
+ aesni_set_key(ctx, in_key, key_len);
kernel_fpu_end();
}

- return err;
+ return 0;
}

Thanks,
Chang