2020-02-25 15:11:33

by Dragos Rosioru (OSS)

Subject: [PATCH] crypto: dcp - fix scatterlist linearization for hash

From: Rosioru Dragos <[email protected]>

The incorrect traversal of the scatterlist, during the linearization phase
lead to computing the hash value of the wrong input buffer.
New implementation uses scatterwalk_map_and_copy()
to address this issue.

Cc: <[email protected]>
Fixes: 15b59e7c3733 ("crypto: mxs - Add Freescale MXS DCP driver")
Signed-off-by: Rosioru Dragos <[email protected]>
---
drivers/crypto/mxs-dcp.c | 58 +++++++++++++++++++++++-------------------------
1 file changed, 28 insertions(+), 30 deletions(-)

diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
index 435ac1c..d845302 100644
--- a/drivers/crypto/mxs-dcp.c
+++ b/drivers/crypto/mxs-dcp.c
@@ -20,6 +20,7 @@
#include <crypto/sha.h>
#include <crypto/internal/hash.h>
#include <crypto/internal/skcipher.h>
+#include <crypto/scatterwalk.h>

#define DCP_MAX_CHANS 4
#define DCP_BUF_SZ PAGE_SIZE
@@ -611,49 +612,46 @@ static int dcp_sha_req_to_buf(struct crypto_async_request *arq)
struct dcp_async_ctx *actx = crypto_ahash_ctx(tfm);
struct dcp_sha_req_ctx *rctx = ahash_request_ctx(req);
struct hash_alg_common *halg = crypto_hash_alg_common(tfm);
- const int nents = sg_nents(req->src);

uint8_t *in_buf = sdcp->coh->sha_in_buf;
uint8_t *out_buf = sdcp->coh->sha_out_buf;

- uint8_t *src_buf;
-
struct scatterlist *src;

- unsigned int i, len, clen;
+ unsigned int i, len, clen, oft = 0;
int ret;

int fin = rctx->fini;
if (fin)
rctx->fini = 0;

- for_each_sg(req->src, src, nents, i) {
- src_buf = sg_virt(src);
- len = sg_dma_len(src);
-
- do {
- if (actx->fill + len > DCP_BUF_SZ)
- clen = DCP_BUF_SZ - actx->fill;
- else
- clen = len;
-
- memcpy(in_buf + actx->fill, src_buf, clen);
- len -= clen;
- src_buf += clen;
- actx->fill += clen;
+ src = req->src;
+ len = req->nbytes;

- /*
- * If we filled the buffer and still have some
- * more data, submit the buffer.
- */
- if (len && actx->fill == DCP_BUF_SZ) {
- ret = mxs_dcp_run_sha(req);
- if (ret)
- return ret;
- actx->fill = 0;
- rctx->init = 0;
- }
- } while (len);
+ while (len) {
+ if (actx->fill + len > DCP_BUF_SZ)
+ clen = DCP_BUF_SZ - actx->fill;
+ else
+ clen = len;
+
+ scatterwalk_map_and_copy(in_buf + actx->fill, src, oft, clen,
+ 0);
+
+ len -= clen;
+ oft += clen;
+ actx->fill += clen;
+
+ /*
+ * If we filled the buffer and still have some
+ * more data, submit the buffer.
+ */
+ if (len && actx->fill == DCP_BUF_SZ) {
+ ret = mxs_dcp_run_sha(req);
+ if (ret)
+ return ret;
+ actx->fill = 0;
+ rctx->init = 0;
+ }
}

if (fin) {
--
2.7.4

2020-02-25 19:34:31

by Horia Geanta

Subject: Re: [PATCH] crypto: dcp - fix scatterlist linearization for hash

On 2/25/2020 5:06 PM, Dragos Rosioru (OSS) wrote:
> From: Rosioru Dragos <[email protected]>
>
> The incorrect traversal of the scatterlist, during the linearization phase
> lead to computing the hash value of the wrong input buffer.
> New implementation uses scatterwalk_map_and_copy()
> to address this issue.
>
> Cc: <[email protected]>
> Fixes: 15b59e7c3733 ("crypto: mxs - Add Freescale MXS DCP driver")
> Signed-off-by: Rosioru Dragos <[email protected]>
Reviewed-by: Horia Geant? <[email protected]>

Thanks,
Horia

2020-03-06 01:51:05

by Herbert Xu

Subject: Re: [PATCH] crypto: dcp - fix scatterlist linearization for hash

On Tue, Feb 25, 2020 at 05:05:52PM +0200, Dragos Rosioru (OSS) wrote:
> From: Rosioru Dragos <[email protected]>
>
> The incorrect traversal of the scatterlist, during the linearization phase
> lead to computing the hash value of the wrong input buffer.
> New implementation uses scatterwalk_map_and_copy()
> to address this issue.
>
> Cc: <[email protected]>
> Fixes: 15b59e7c3733 ("crypto: mxs - Add Freescale MXS DCP driver")
> Signed-off-by: Rosioru Dragos <[email protected]>
> ---
> drivers/crypto/mxs-dcp.c | 58 +++++++++++++++++++++++-------------------------
> 1 file changed, 28 insertions(+), 30 deletions(-)

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt