[3.19.y-ckt stable] Patch "crypto: ccp - Prevent information leakage on export" has been added to the 3.19.y-ckt tree

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    crypto: ccp - Prevent information leakage on export

to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue

This patch is scheduled to be released in version 3.19.8-ckt20.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.19.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

---8<------------------------------------------------------------

>From a43a28058a4e71645a722db4dff8bce13e4b8f60 Mon Sep 17 00:00:00 2001
From: Tom Lendacky <thomas.lendacky at amd.com>
Date: Wed, 13 Apr 2016 10:52:25 -0500
Subject: crypto: ccp - Prevent information leakage on export

commit f709b45ec461b548c41a00044dba1f1b572783bf upstream.

Prevent information from leaking to userspace by doing a memset to 0 of
the export state structure before setting the structure values and copying
it. This prevents un-initialized padding areas from being copied into the
export area.

Reported-by: Ben Hutchings <ben at decadent.org.uk>
Signed-off-by: Tom Lendacky <thomas.lendacky at amd.com>
Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/crypto/ccp/ccp-crypto-aes-cmac.c | 3 +++
 drivers/crypto/ccp/ccp-crypto-sha.c      | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
index 5c93afb..f10b499 100644
--- a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
@@ -206,6 +206,9 @@ static int ccp_aes_cmac_export(struct ahash_request *req, void *out)
 	struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
 	struct ccp_aes_cmac_exp_ctx state;

+	/* Don't let anything leak to 'out' */
+	memset(&state, 0, sizeof(state));
+
 	state.null_msg = rctx->null_msg;
 	memcpy(state.iv, rctx->iv, sizeof(state.iv));
 	state.buf_count = rctx->buf_count;
diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
index b368e98..ced9f38 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -198,6 +198,9 @@ static int ccp_sha_export(struct ahash_request *req, void *out)
 	struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
 	struct ccp_sha_exp_ctx state;

+	/* Don't let anything leak to 'out' */
+	memset(&state, 0, sizeof(state));
+
 	state.type = rctx->type;
 	state.msg_bits = rctx->msg_bits;
 	state.first = rctx->first;
--
2.7.4