Patch "crypto: ccp - Fix AES XTS error for request sizes above 4096" has been added to the 4.4-stable tree

Patch "crypto: ccp - Fix AES XTS error for request sizes above 4096" has been added to the 4.4-stable tree

[gregkh]

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

    crypto: ccp - Fix AES XTS error for request sizes above 4096

to the 4.4-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-ccp-fix-aes-xts-error-for-request-sizes-above-4096.patch
and it can be found in the queue-4.4 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 ab6a11a7c8ef47f996974dd3c648c2c0b1a36ab1 Mon Sep 17 00:00:00 2001
From: Tom Lendacky <thomas.lendacky@amd.com>
Date: Fri, 20 May 2016 17:33:03 -0500
Subject: crypto: ccp - Fix AES XTS error for request sizes above 4096

From: Tom Lendacky <thomas.lendacky@amd.com>

commit ab6a11a7c8ef47f996974dd3c648c2c0b1a36ab1 upstream.

The ccp-crypto module for AES XTS support has a bug that can allow requests
greater than 4096 bytes in size to be passed to the CCP hardware. The CCP
hardware does not support request sizes larger than 4096, resulting in
incorrect output. The request should actually be handled by the fallback
mechanism instantiated by the ccp-crypto module.

Add a check to insure the request size is less than or equal to the maximum
supported size and use the fallback mechanism if it is not.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/crypto/ccp/ccp-crypto-aes-xts.c |   17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

--- a/drivers/crypto/ccp/ccp-crypto-aes-xts.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
@@ -122,6 +122,7 @@ static int ccp_aes_xts_crypt(struct ablk
 	struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
 	struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
 	unsigned int unit;
+	u32 unit_size;
 	int ret;
 
 	if (!ctx->u.aes.key_len)
@@ -133,11 +134,17 @@ static int ccp_aes_xts_crypt(struct ablk
 	if (!req->info)
 		return -EINVAL;
 
-	for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++)
-		if (!(req->nbytes & (unit_size_map[unit].size - 1)))
-			break;
+	unit_size = CCP_XTS_AES_UNIT_SIZE__LAST;
+	if (req->nbytes <= unit_size_map[0].size) {
+		for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++) {
+			if (!(req->nbytes & (unit_size_map[unit].size - 1))) {
+				unit_size = unit_size_map[unit].value;
+				break;
+			}
+		}
+	}
 
-	if ((unit_size_map[unit].value == CCP_XTS_AES_UNIT_SIZE__LAST) ||
+	if ((unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) ||
 	    (ctx->u.aes.key_len != AES_KEYSIZE_128)) {
 		/* Use the fallback to process the request for any
 		 * unsupported unit sizes or key sizes
@@ -158,7 +165,7 @@ static int ccp_aes_xts_crypt(struct ablk
 	rctx->cmd.engine = CCP_ENGINE_XTS_AES_128;
 	rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT
 					   : CCP_AES_ACTION_DECRYPT;
-	rctx->cmd.u.xts.unit_size = unit_size_map[unit].value;
+	rctx->cmd.u.xts.unit_size = unit_size;
 	rctx->cmd.u.xts.key = &ctx->u.aes.key_sg;
 	rctx->cmd.u.xts.key_len = ctx->u.aes.key_len;
 	rctx->cmd.u.xts.iv = &rctx->iv_sg;


Patches currently in stable-queue which might be from thomas.lendacky@amd.com are

queue-4.4/crypto-ccp-fix-aes-xts-error-for-request-sizes-above-4096.patch