On 2017/11/7 1:00, Eric Blake wrote:
> On 11/06/2017 12:21 AM, Longpeng(Mike) wrote:
>> Test-crypto-hash calls qcrypto_hash_bytesv/digest/base64 with
>> errp=NULL, this will cause a NULL poniter deference if afalg_driver
>
> s/poniter deference/pointer dereference/
>
OK.
>> doesn't support requested algos:
>> ret = qcrypto_hash_afalg_driver.hash_bytesv(alg, iov, niov,
>> result, resultlen,
>> errp);
>> if (ret == 0) {
>> return ret;
>> }
>>
>> error_free(*errp); // <--- here
>>
>> So we must check 'errp & *errp' before dereference.
>
> No, if we are going to blindly ignore the error from the hash_bytesv()
> call, then we should pass NULL rather than errp.
>
The 'errp' in this palce is convenient for debug, it can tell us the reason for
failure without stepping into afalg_driver's hash_bytesv().
>>
>> Signed-off-by: Longpeng(Mike) <longpe...@huawei.com>
>> ---
>> crypto/hash.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/crypto/hash.c b/crypto/hash.c
>> index ac59c63..c464c78 100644
>> --- a/crypto/hash.c
>> +++ b/crypto/hash.c
>> @@ -60,7 +60,9 @@ int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
>> * TODO:
>> * Maybe we should treat some afalg errors as fatal
>> */
>> - error_free(*errp);
>> + if (errp && *errp) {
>> + error_free(*errp);
>> + }
>
> Any code that uses 'if (errp && *errp)' is suspicious; I think you need
I see, thanks a lot.
> a v2 that doesn't try to set errp in the first place, rather than
> cleaning it up to ignore it after the fact.
>
I answered above.
How about the following approach?
int qcrypto_hash_bytesv(...Error **errp)
{
#ifdef CONFIG_AF_ALG
int ret;
Error *err2 = NULL;
ret = qcrypto_hash_afalg_driver.hash_bytesv(alg, iov, niov,
result, resultlen,
&err2);
if (ret == 0) {
return ret;
}
error_free(*err2);
#endif
return qcrypto_hash_lib_driver.hash_bytesv(alg, iov, niov,
result, resultlen,
errp);
}
I'll send a V2 if there's no objection, otherwise I'll pick your suggested
approach. :)
--
Regards,
Longpeng(Mike)
