crypto: sahara - fix processing hash requests with req->nbytes < sg->length

[ Upstream commit 7bafa74d1ba35dcc173e1ce915e983d65905f77e ]

It's not always the case that the entire sg entry needs to be processed.
Currently, when nbytes is less than sg->length, "Descriptor length" errors
are encountered.

To fix this, take the actual request size into account when populating the
hw links.

Fixes: 5a2bb93f5992 ("crypto: sahara - add support for SHA1/256")
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/crypto/sahara.c b/drivers/crypto/sahara.c
index 117aa42..477b4d8 100644 (file)
--- a/drivers/crypto/sahara.c
+++ b/drivers/crypto/sahara.c
@@ -776,6 +776,7 @@ static int sahara_sha_hw_links_create(struct sahara_dev *dev,
                                       int start)
 {
        struct scatterlist *sg;
+       unsigned int len;
        unsigned int i;
        int ret;
 
@@ -797,12 +798,14 @@ static int sahara_sha_hw_links_create(struct sahara_dev *dev,
        if (!ret)
                return -EFAULT;
 
+       len = rctx->total;
        for (i = start; i < dev->nb_in_sg + start; i++) {
-               dev->hw_link[i]->len = sg->length;
+               dev->hw_link[i]->len = min(len, sg->length);
                dev->hw_link[i]->p = sg->dma_address;
                if (i == (dev->nb_in_sg + start - 1)) {
                        dev->hw_link[i]->next = 0;
                } else {
+                       len -= min(len, sg->length);
                        dev->hw_link[i]->next = dev->hw_phys_link[i + 1];
                        sg = sg_next(sg);
                }