crypto: omap-sham - huge buffer access fixes

[ Upstream commit 6395166d7a19019d5e9574eb9ecdaf0028abb887 ]

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>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/crypto/omap-sham.c b/drivers/crypto/omap-sham.c
index e4072cd385857cffae2bf41ecdcc82282c079e73..0cbf9c932a0f005b8836a9096deee0a75448fece 100644 (file)
--- 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,