[PATCH v4 15/15] crypto: ti - Change lengths in AEAD to u64 to avoid potential overflows

[T Pratham <t-pratham@ti.com>]

Change assoclen, cryptlen, authsize from unsigned int to u64 to avoid
overflow when they are added (in TAG offset and padding length
calculation)

Fixes: 37b902c603042 ("crypto: ti - Add support for AES-GCM in DTHEv2 driver")
Signed-off-by: T Pratham <t-pratham@ti.com>
---
 drivers/crypto/ti/dthev2-aes.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/crypto/ti/dthev2-aes.c b/drivers/crypto/ti/dthev2-aes.c
index 9b982ca4a7730..ca87aacc39c5d 100644
--- a/drivers/crypto/ti/dthev2-aes.c
+++ b/drivers/crypto/ti/dthev2-aes.c
@@ -756,6 +756,9 @@ static int dthe_aead_enc_get_tag(struct aead_request *req)
 	struct dthe_tfm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 	struct dthe_aes_req_ctx *rctx = aead_request_ctx(req);
 	u32 tag[AES_BLOCK_WORDS];
+	u64 assoclen = req->assoclen;
+	u64 cryptlen = req->cryptlen;
+	u64 authsize = ctx->authsize;
 	int nents;
 	int ret;
 
@@ -763,12 +766,12 @@ static int dthe_aead_enc_get_tag(struct aead_request *req)
 	if (ret)
 		return ret;
 
-	nents = sg_nents_for_len(req->dst, req->cryptlen + req->assoclen + ctx->authsize);
+	nents = sg_nents_for_len(req->dst, cryptlen + assoclen + authsize);
 	if (nents < 0)
 		return nents;
 
-	sg_pcopy_from_buffer(req->dst, nents, tag, ctx->authsize,
-			     req->assoclen + req->cryptlen);
+	sg_pcopy_from_buffer(req->dst, nents, tag, authsize,
+			     assoclen + cryptlen);
 
 	return 0;
 }
@@ -779,6 +782,9 @@ static int dthe_aead_dec_verify_tag(struct aead_request *req)
 	struct dthe_aes_req_ctx *rctx = aead_request_ctx(req);
 	u32 tag_out[AES_BLOCK_WORDS];
 	u32 tag_in[AES_BLOCK_WORDS];
+	u64 assoclen = req->assoclen;
+	u64 cryptlen = req->cryptlen;
+	u64 authsize = ctx->authsize;
 	int nents;
 	int ret;
 
@@ -786,14 +792,14 @@ static int dthe_aead_dec_verify_tag(struct aead_request *req)
 	if (ret)
 		return ret;
 
-	nents = sg_nents_for_len(req->src, req->assoclen + req->cryptlen);
+	nents = sg_nents_for_len(req->src, assoclen + cryptlen);
 	if (nents < 0)
 		return nents;
 
-	sg_pcopy_to_buffer(req->src, nents, tag_in, ctx->authsize,
-			   req->assoclen + req->cryptlen - ctx->authsize);
+	sg_pcopy_to_buffer(req->src, nents, tag_in, authsize,
+			   assoclen + cryptlen - authsize);
 
-	if (crypto_memneq(tag_in, tag_out, ctx->authsize))
+	if (crypto_memneq(tag_in, tag_out, authsize))
 		return -EBADMSG;
 	else
 		return 0;
@@ -887,10 +893,10 @@ static int dthe_aead_run(struct crypto_engine *engine, void *areq)
 	struct dthe_aes_req_ctx *rctx = aead_request_ctx(req);
 	struct dthe_data *dev_data = rctx->dev_data;
 
-	unsigned int cryptlen = req->cryptlen;
-	unsigned int assoclen = req->assoclen;
-	unsigned int authsize = ctx->authsize;
-	unsigned int unpadded_cryptlen;
+	u64 cryptlen = req->cryptlen;
+	u64 assoclen = req->assoclen;
+	u64 authsize = ctx->authsize;
+	u64 unpadded_cryptlen;
 	struct scatterlist *src = NULL;
 	struct scatterlist *dst = NULL;
 	struct scatterlist *aad_sg = NULL;
-- 
2.34.1