crypto: ccp - Check for caller result area before using it

For a hash operation, the caller doesn't have to supply a result
area on every call so don't use it / update it if it hasn't
been supplied.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 8 insertions, 3 deletions

diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
index 646c8d1bd03c..c6b8f9e56aab 100644
--- a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
@@ -43,7 +43,9 @@ static int ccp_aes_cmac_complete(struct crypto_async_request *async_req,
         } else
                 rctx->buf_count = 0;
 
-        memcpy(req->result, rctx->iv, digest_size);
+        /* Update result area if supplied */
+        if (req->result)
+                memcpy(req->result, rctx->iv, digest_size);
 
 e_free:
         sg_free_table(&rctx->data_sg);
diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
index bf913cbb3e96..183d16e46d20 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -74,6 +74,7 @@ static int ccp_sha_finish_hmac(struct crypto_async_request *async_req)
         struct ahash_request *req = ahash_request_cast(async_req);
         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
         struct ccp_ctx *ctx = crypto_ahash_ctx(tfm);
+        struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
         struct scatterlist sg[2];
         unsigned int block_size =
                 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm));
@@ -81,7 +82,7 @@ static int ccp_sha_finish_hmac(struct crypto_async_request *async_req)
 
         sg_init_table(sg, ARRAY_SIZE(sg));
         sg_set_buf(&sg[0], ctx->u.sha.opad, block_size);
-        sg_set_buf(&sg[1], req->result, digest_size);
+        sg_set_buf(&sg[1], rctx->ctx, digest_size);
 
         return ccp_sync_hash(ctx->u.sha.hmac_tfm, req->result, sg,
                              block_size + digest_size);
@@ -106,7 +107,9 @@ static int ccp_sha_complete(struct crypto_async_request *async_req, int ret)
         } else
                 rctx->buf_count = 0;
 
-        memcpy(req->result, rctx->ctx, digest_size);
+        /* Update result area if supplied */
+        if (req->result)
+                memcpy(req->result, rctx->ctx, digest_size);
 
         /* If we're doing an HMAC, we need to perform that on the final op */
         if (rctx->final && ctx->u.sha.key_len)