crypto: caam - fix copy of next buffer for xcbc and cmac

Fix a side effect of adding xcbc support, when the next_buffer is not
copied.
The issue occurs, when there is stored from previous state a blocksize
buffer and received, a less than blocksize, from user. In this case, the
nents for req->src is 0, and the next_buffer is not copied.
An example is:
{
	.tap	= { 17, 15, 8 },
	.psize	= 40,
	.np	= 3,
	.ksize	= 16,
}

Fixes: 12b8567f6fa4 ("crypto: caam - add support for xcbc(aes)")
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
(cherry picked from commit b4e9e931e9bb2f5b302ce66640832f5a3e57e8c4)

diff --git a/drivers/crypto/caam/caamhash.c b/drivers/crypto/caam/caamhash.c
index 2ea82f3..ca70d8a 100644 (file)
--- a/drivers/crypto/caam/caamhash.c
+++ b/drivers/crypto/caam/caamhash.c
@@ -813,19 +813,18 @@ static int ahash_update_ctx(struct ahash_request *req)
                if (ret)
                        goto unmap_ctx;
 
-               if (mapped_nents) {
+               if (mapped_nents)
                        sg_to_sec4_sg_last(req->src, mapped_nents,
                                           edesc->sec4_sg + sec4_sg_src_index,
                                           0);
-                       if (*next_buflen)
-                               scatterwalk_map_and_copy(next_buf, req->src,
-                                                        to_hash - *buflen,
-                                                        *next_buflen, 0);
-               } else {
+               else
                        sg_to_sec4_set_last(edesc->sec4_sg + sec4_sg_src_index -
                                            1);
-               }
 
+               if (*next_buflen)
+                       scatterwalk_map_and_copy(next_buf, req->src,
+                                                to_hash - *buflen,
+                                                *next_buflen, 0);
                desc = edesc->hw_desc;
 
                edesc->sec4_sg_dma = dma_map_single(jrdev, edesc->sec4_sg,