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Patch "crypto: ccp - Fix AES XTS error for request sizes above 4096" has been added to the 4.6-stable tree

PATCH [email protected] 1 participant 1 message Jun 18, 2016

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Stable branch Crypto API AMD cryptographic coprocessor (CCP) driver
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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 4.6-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-4.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From ab6a11a7c8ef47f996974dd3c648c2c0b1a36ab1 Mon Sep 17 00:00:00 2001

From: Tom Lendacky <[email protected]>
Date: Fri, 20 May 2016 17:33:03 -0500
Subject: crypto: ccp - Fix AES XTS error for request sizes above 4096

From: Tom Lendacky <[email protected]>

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 <[email protected]>
Signed-off-by Herbert Xu <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/crypto/ccp/ccp-crypto-aes-xts.c |   17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)
drivers/crypto/ccp/ccp-crypto-aes-xts.c +12 -5
@@ -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 [email protected] are

queue-4.6/crypto-ccp-fix-aes-xts-error-for-request-sizes-above-4096.patch