Am Mittwoch, 23. August 2017, 09:41:11 CEST schrieb Gilad Ben-Yossef:
Hi Gilad,
>
> if (areq) {
> + /*
> + * The crypto API expects us to set the req->info to the last
> + * ciphertext block. For encrypt, simply copy from the result.
> + * For decrypt, we must copy from a saved buffer since this
> + * could be an in-place decryption operation and the src is
> + * lost by this point.
> + */
> + if (req_ctx->gen_ctx.op_type == DRV_CRYPTO_DIRECTION_DECRYPT) {
> + memcpy(req->info, req_ctx->backup_info, ivsize);
> + kfree(req_ctx->backup_info);
> + } else {
> + scatterwalk_map_and_copy(req->info, req->dst,
> + (req->nbytes - ivsize),
> + ivsize, 0);
> + }
> +
> ablkcipher_request_complete(areq, completion_error);
> return 0;
> }
> @@ -858,7 +876,6 @@ static int ssi_ablkcipher_encrypt(struct
> ablkcipher_request *req) struct blkcipher_req_ctx *req_ctx =
> ablkcipher_request_ctx(req); unsigned int ivsize =
> crypto_ablkcipher_ivsize(ablk_tfm);
>
> - req_ctx->backup_info = req->info;
> req_ctx->is_giv = false;
>
> return ssi_blkcipher_process(tfm, req_ctx, req->dst, req->src,
> req->nbytes, req->info, ivsize, (void *)req, DRV_CRYPTO_DIRECTION_ENCRYPT);
> @@ -871,8 +888,18 @@ static int ssi_ablkcipher_decrypt(struct
> ablkcipher_request *req) struct blkcipher_req_ctx *req_ctx =
> ablkcipher_request_ctx(req); unsigned int ivsize =
> crypto_ablkcipher_ivsize(ablk_tfm);
>
> - req_ctx->backup_info = req->info;
> + /*
> + * Allocate and save the last IV sized bytes of the source, which will
> + * be lost in case of in-place decryption and might be needed for CTS.
> + */
> + req_ctx->backup_info = kmalloc(ivsize, GFP_KERNEL);
> + if (!req_ctx->backup_info)
> + return -ENOMEM;
Are you sure you do not add a memleak here? You seem to unconditionally
allocate memory but conditionally free it.
Ciao
Stephan
