crypto: ccp - memset request context to zero during import

Since a crypto_ahash_import() can be called against a request context
that has not had a crypto_ahash_init() performed, the request context
needs to be cleared to insure there is no random data present. If not,
the random data can result in a kernel oops during crypto_ahash_update().

Cc: <stable@vger.kernel.org> # 3.14.x-
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccp/ccp-crypto-aes-cmac.c

@@ -244,6 +244,7 @@ static int ccp_aes_cmac_import(struct ahash_request *req, const void *in)
 	/* 'in' may not be aligned so memcpy to local variable */
 	memcpy(&state, in, sizeof(state));
 
+	memset(rctx, 0, sizeof(*rctx));
 	rctx->null_msg = state.null_msg;
 	memcpy(rctx->iv, state.iv, sizeof(rctx->iv));
 	rctx->buf_count = state.buf_count;