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

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 <[email protected]> know about it.

From: Tero Kristo <[email protected]>
Date: Wed, 24 May 2017 10:35:32 +0300
Subject: crypto: omap-sham - buffer handling fixes for hashing later

From: Tero Kristo <[email protected]>

[ 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.

---
 drivers/crypto/omap-sham.c |   22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

@@ -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 [email protected] 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