crypto: ccp - Prevent information leakage on export

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.

Cc: <stable@vger.kernel.org> # 3.14.x-
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>

diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
index 3d9acc53d2473818d1e37c4af432a4afcbdf4ec4..60fc0fa26fd3b19ab557888d9bd6e61c208fe0f6 100644 (file)
--- 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 b5ad72897dc25b8d11642315f3e087af32d1c845..8f36af62fe951032d22dfd9f7ea0150e43d6360b 100644 (file)
--- 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;