[RESEND PATCHv3 4/7] crypto: omap-sham: huge buffer access fixes

[Tero Kristo <t-kristo@ti.com>]

The ctx internal buffer can only hold buflen amount of data, don't try
to copy over more than that. Also, initialize the context sg pointer
if we only have data in the context internal buffer, this can happen
when closing a hash with certain data amounts.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
---
 drivers/crypto/omap-sham.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index 0c837bbd8f0c..9823d7dfca9c 100644
--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -751,8 +751,15 @@ static int omap_sham_align_sgs(struct scatterlist *sg,
 	int offset = rctx->offset;
 	int bufcnt = rctx->bufcnt;
 
-	if (!sg || !sg->length || !nbytes)
+	if (!sg || !sg->length || !nbytes) {
+		if (bufcnt) {
+			sg_init_table(rctx->sgl, 1);
+			sg_set_buf(rctx->sgl, rctx->dd->xmit_buf, bufcnt);
+			rctx->sg = rctx->sgl;
+		}
+
 		return 0;
+	}
 
 	new_len = nbytes;
 
@@ -896,7 +903,7 @@ static int omap_sham_prepare_request(struct ahash_request *req, bool update)
 	if (hash_later < 0)
 		hash_later = 0;
 
-	if (hash_later) {
+	if (hash_later && hash_later <= rctx->buflen) {
 		scatterwalk_map_and_copy(rctx->buffer,
 					 req->src,
 					 req->nbytes - hash_later,
-- 
2.17.1

--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki