Patch "crypto: omap-sham - buffer handling fixes for hashing later" has been added to the 4.9-stable tree

Patch "crypto: omap-sham - buffer handling fixes for hashing later" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    crypto: omap-sham - buffer handling fixes for hashing later

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     crypto-omap-sham-buffer-handling-fixes-for-hashing-later.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Apr  9 17:09:24 CEST 2018
From: Tero Kristo <t-kristo@ti.com>
Date: Wed, 24 May 2017 10:35:32 +0300
Subject: crypto: omap-sham - buffer handling fixes for hashing later

From: Tero Kristo <t-kristo@ti.com>


[ Upstream commit 5d78d57ede8f9e7f656c610ed25be7be337e0529 ]

Currently, the hash later code only handles the cases when we have
either new data coming in with the request or old data in the buffer,
but not the combination when we have both. Fix this by changing the
ordering of the code a bit and handling both cases properly
simultaneously if needed. Also, fix an issue with omap_sham_update
that surfaces with this fix, so that the code checks the bufcnt
instead of total data amount against buffer length to avoid any
buffer overflows.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/crypto/omap-sham.c |   22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

--- a/drivers/crypto/omap-sham.c
+++ b/drivers/crypto/omap-sham.c
@@ -873,14 +873,21 @@ static int omap_sham_prepare_request(str
 	}
 
 	if (hash_later) {
-		if (req->nbytes) {
-			scatterwalk_map_and_copy(rctx->buffer, req->src,
-						 req->nbytes - hash_later,
-						 hash_later, 0);
-		} else {
+		int offset = 0;
+
+		if (hash_later > req->nbytes) {
 			memcpy(rctx->buffer, rctx->buffer + xmit_len,
-			       hash_later);
+			       hash_later - req->nbytes);
+			offset = hash_later - req->nbytes;
+		}
+
+		if (req->nbytes) {
+			scatterwalk_map_and_copy(rctx->buffer + offset,
+						 req->src,
+						 offset + req->nbytes -
+						 hash_later, hash_later, 0);
 		}
+
 		rctx->bufcnt = hash_later;
 	} else {
 		rctx->bufcnt = 0;
@@ -1189,11 +1196,10 @@ static int omap_sham_update(struct ahash
 	if (!req->nbytes)
 		return 0;
 
-	if (ctx->total + req->nbytes < ctx->buflen) {
+	if (ctx->bufcnt + req->nbytes <= ctx->buflen) {
 		scatterwalk_map_and_copy(ctx->buffer + ctx->bufcnt, req->src,
 					 0, req->nbytes, 0);
 		ctx->bufcnt += req->nbytes;
-		ctx->total += req->nbytes;
 		return 0;
 	}
 


Patches currently in stable-queue which might be from t-kristo@ti.com are

queue-4.9/crypto-omap-sham-fix-closing-of-hash-with-separate-finalize-call.patch
queue-4.9/crypto-omap-sham-buffer-handling-fixes-for-hashing-later.patch