From: Tom Lendacky <thomas.lendacky@amd.com>
Date: Wed, 13 Apr 2016 15:52:25 +0000 (-0500)
Subject: crypto: ccp - Prevent information leakage on export
X-Git-Tag: firefly_0821_release~176^2~4^2~48^2~116
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1575fcd167e3452cadbcf7d04ad6277c875a482f;p=firefly-linux-kernel-4.4.55.git

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@decadent.org.uk>
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>
---

diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
index 3d9acc53d247..60fc0fa26fd3 100644
--- a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
@@ -225,6 +225,9 @@ 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 8ef06fad8b14..ab9945f2cb7a 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -212,6 +212,9 @@ 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;