From: Lokesh Vutla <a0131...@ti.com>

For cases where total length of an input SGs is not same as
length of the input data for encryption, omap-des driver
crashes. This happens in the case when IPsec is trying to use
omap-des driver.

To avoid this, we copy all the pages from the input SG list
into a contiguous buffer and prepare a single element SG list
for this buffer with length as the total bytes to crypt, which is
similar thing that is done in case of unaligned lengths.

Signed-off-by: Lokesh Vutla <lokeshvu...@ti.com>
Tested-by: Aparna Balasubramanian <apar...@ti.com>
Signed-off-by: Tero Kristo <t-kri...@ti.com>
---
 drivers/crypto/omap-des.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/drivers/crypto/omap-des.c b/drivers/crypto/omap-des.c
index 3eedb03..e4c87bc 100644
--- a/drivers/crypto/omap-des.c
+++ b/drivers/crypto/omap-des.c
@@ -521,29 +521,36 @@ static int omap_des_crypt_dma_stop(struct omap_des_dev 
*dd)
        return 0;
 }
 
-static int omap_des_copy_needed(struct scatterlist *sg)
+static int omap_des_copy_needed(struct scatterlist *sg, int total)
 {
+       int len = 0;
+
+       if (!IS_ALIGNED(total, DES_BLOCK_SIZE))
+               return -1;
+
        while (sg) {
                if (!IS_ALIGNED(sg->offset, 4))
                        return -1;
                if (!IS_ALIGNED(sg->length, DES_BLOCK_SIZE))
                        return -1;
+
+               len += sg->length;
                sg = sg_next(sg);
        }
+
+       if (len != total)
+               return -1;
+
        return 0;
 }
 
 static int omap_des_copy_sgs(struct omap_des_dev *dd)
 {
        void *buf_in, *buf_out;
-       int pages;
-
-       pages = dd->total >> PAGE_SHIFT;
-
-       if (dd->total & (PAGE_SIZE-1))
-               pages++;
+       int pages, total;
 
-       BUG_ON(!pages);
+       total = ALIGN(dd->total, DES_BLOCK_SIZE);
+       pages = get_order(total);
 
        buf_in = (void *)__get_free_pages(GFP_ATOMIC, pages);
        buf_out = (void *)__get_free_pages(GFP_ATOMIC, pages);
@@ -595,8 +602,8 @@ static int omap_des_prepare_req(struct crypto_engine 
*engine,
        dd->in_sg = req->src;
        dd->out_sg = req->dst;
 
-       if (omap_des_copy_needed(dd->in_sg) ||
-           omap_des_copy_needed(dd->out_sg)) {
+       if (omap_des_copy_needed(dd->in_sg, dd->total) ||
+           omap_des_copy_needed(dd->out_sg, dd->total)) {
                if (omap_des_copy_sgs(dd))
                        pr_err("Failed to copy SGs for unaligned cases\n");
                dd->sgs_copied = 1;
-- 
1.9.1

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