[PATCH AUTOSEL 4.9 22/73] crypto: talitos - properly handle split ICV.

[Sasha Levin]

From: Christophe Leroy <christophe.le...@c-s.fr>

[ Upstream commit eae55a586c3c8b50982bad3c3426e9c9dd7a0075 ]

The driver assumes that the ICV is as a single piece in the last
element of the scatterlist. This assumption is wrong.

This patch ensures that the ICV is properly handled regardless of
the scatterlist layout.

Fixes: 9c4a79653b35 ("crypto: talitos - Freescale integrated security engine 
(SEC) driver")
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 drivers/crypto/talitos.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/crypto/talitos.c b/drivers/crypto/talitos.c
index 166e216b02b2..36d4f2a32e54 100644
--- a/drivers/crypto/talitos.c
+++ b/drivers/crypto/talitos.c
@@ -984,7 +984,6 @@ static void ipsec_esp_encrypt_done(struct device *dev,
        struct crypto_aead *authenc = crypto_aead_reqtfm(areq);
        unsigned int authsize = crypto_aead_authsize(authenc);
        struct talitos_edesc *edesc;
-       struct scatterlist *sg;
        void *icvdata;
 
        edesc = container_of(desc, struct talitos_edesc, desc);
@@ -998,9 +997,8 @@ static void ipsec_esp_encrypt_done(struct device *dev,
                else
                        icvdata = &edesc->link_tbl[edesc->src_nents +
                                                   edesc->dst_nents + 2];
-               sg = sg_last(areq->dst, edesc->dst_nents);
-               memcpy((char *)sg_virt(sg) + sg->length - authsize,
-                      icvdata, authsize);
+               sg_pcopy_from_buffer(areq->dst, edesc->dst_nents ? : 1, icvdata,
+                                    authsize, areq->assoclen + areq->cryptlen);
        }
 
        kfree(edesc);
@@ -1016,7 +1014,6 @@ static void ipsec_esp_decrypt_swauth_done(struct device 
*dev,
        struct crypto_aead *authenc = crypto_aead_reqtfm(req);
        unsigned int authsize = crypto_aead_authsize(authenc);
        struct talitos_edesc *edesc;
-       struct scatterlist *sg;
        char *oicv, *icv;
        struct talitos_private *priv = dev_get_drvdata(dev);
        bool is_sec1 = has_ftr_sec1(priv);
@@ -1026,9 +1023,18 @@ static void ipsec_esp_decrypt_swauth_done(struct device 
*dev,
        ipsec_esp_unmap(dev, edesc, req);
 
        if (!err) {
+               char icvdata[SHA512_DIGEST_SIZE];
+               int nents = edesc->dst_nents ? : 1;
+               unsigned int len = req->assoclen + req->cryptlen;
+
                /* auth check */
-               sg = sg_last(req->dst, edesc->dst_nents ? : 1);
-               icv = (char *)sg_virt(sg) + sg->length - authsize;
+               if (nents > 1) {
+                       sg_pcopy_to_buffer(req->dst, nents, icvdata, authsize,
+                                          len - authsize);
+                       icv = icvdata;
+               } else {
+                       icv = (char *)sg_virt(req->dst) + len - authsize;
+               }
 
                if (edesc->dma_len) {
                        if (is_sec1)
@@ -1458,7 +1464,6 @@ static int aead_decrypt(struct aead_request *req)
        struct talitos_ctx *ctx = crypto_aead_ctx(authenc);
        struct talitos_private *priv = dev_get_drvdata(ctx->dev);
        struct talitos_edesc *edesc;
-       struct scatterlist *sg;
        void *icvdata;
 
        req->cryptlen -= authsize;
@@ -1493,9 +1498,8 @@ static int aead_decrypt(struct aead_request *req)
        else
                icvdata = &edesc->link_tbl[0];
 
-       sg = sg_last(req->src, edesc->src_nents ? : 1);
-
-       memcpy(icvdata, (char *)sg_virt(sg) + sg->length - authsize, authsize);
+       sg_pcopy_to_buffer(req->src, edesc->src_nents ? : 1, icvdata, authsize,
+                          req->assoclen + req->cryptlen - authsize);
 
        return ipsec_esp(edesc, req, ipsec_esp_decrypt_swauth_done);
 }
-- 
2.20.1