Re: [PATCH -net] tls: return -EFAULT if copy_to_user() fails

Dave Watson
2017-06-23T16:12:08Z

On 06/23/17 01:15 PM, Dan Carpenter wrote:
> The copy_to_user() function returns the number of bytes remaining but we
> want to return -EFAULT here.
>
> Fixes: 3c4d7559159b ("tls: kernel TLS support")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Acked-by: Dave Watson <davejwatson@fb.com>

Yes, -EFAULT seems like the correct choice here, the return from
copy_to_user isn't useful. Thanks

>
> diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c
> index 2ebc328bda96..a03130a47b85 100644
> --- a/net/tls/tls_main.c
> +++ b/net/tls/tls_main.c
> @@ -273,7 +273,8 @@ static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
> }
>
> if (len = sizeof(crypto_info)) {
> - rc = copy_to_user(optval, crypto_info, sizeof(*crypto_info));
> + if (copy_to_user(optval, crypto_info, sizeof(*crypto_info)))
> + rc = -EFAULT;
> goto out;
> }
>
> @@ -293,9 +294,10 @@ static int do_tls_getsockopt_tx(struct sock *sk, char __user *optval,
> memcpy(crypto_info_aes_gcm_128->iv, ctx->iv,
> TLS_CIPHER_AES_GCM_128_IV_SIZE);
> release_sock(sk);
> - rc = copy_to_user(optval,
> - crypto_info_aes_gcm_128,
> - sizeof(*crypto_info_aes_gcm_128));
> + if (copy_to_user(optval,
> + crypto_info_aes_gcm_128,
> + sizeof(*crypto_info_aes_gcm_128)))
> + rc = -EFAULT;
> break;
> }