[PATCH 4.2.y-ckt 026/218] crypto: ccp - Don't assume export/import areas are aligned

From: Kamal Mostafa
Date: Thu Mar 31 2016 - 17:19:39 EST


4.2.8-ckt7 -stable review patch. If anyone has any objections, please let me know.

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

From: Tom Lendacky <thomas.lendacky@xxxxxxx>

commit b31dde2a5cb1bf764282abf934266b7193c2bc7c upstream.

Use a local variable for the exported and imported state so that
alignment is not an issue. On export, set a local variable from the
request context and then memcpy the contents of the local variable to
the export memory area. On import, memcpy the import memory area into
a local variable and then use the local variable to set the request
context.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/crypto/ccp/ccp-crypto-aes-cmac.c | 26 ++++++++++++++---------
drivers/crypto/ccp/ccp-crypto-sha.c | 36 +++++++++++++++++++-------------
2 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
index 2af9c09..8680b18 100644
--- a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
@@ -205,12 +205,15 @@ static int ccp_aes_cmac_digest(struct ahash_request *req)
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 = out;
+ struct ccp_aes_cmac_exp_ctx state;

- state->null_msg = rctx->null_msg;
- memcpy(state->iv, rctx->iv, sizeof(state->iv));
- state->buf_count = rctx->buf_count;
- memcpy(state->buf, rctx->buf, sizeof(state->buf));
+ state.null_msg = rctx->null_msg;
+ memcpy(state.iv, rctx->iv, sizeof(state.iv));
+ state.buf_count = rctx->buf_count;
+ memcpy(state.buf, rctx->buf, sizeof(state.buf));
+
+ /* 'out' may not be aligned so memcpy from local variable */
+ memcpy(out, &state, sizeof(state));

return 0;
}
@@ -218,12 +221,15 @@ static int ccp_aes_cmac_export(struct ahash_request *req, void *out)
static int ccp_aes_cmac_import(struct ahash_request *req, const void *in)
{
struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req);
- const struct ccp_aes_cmac_exp_ctx *state = in;
+ struct ccp_aes_cmac_exp_ctx state;
+
+ /* 'in' may not be aligned so memcpy to local variable */
+ memcpy(&state, in, sizeof(state));

- rctx->null_msg = state->null_msg;
- memcpy(rctx->iv, state->iv, sizeof(rctx->iv));
- rctx->buf_count = state->buf_count;
- memcpy(rctx->buf, state->buf, sizeof(rctx->buf));
+ rctx->null_msg = state.null_msg;
+ memcpy(rctx->iv, state.iv, sizeof(rctx->iv));
+ rctx->buf_count = state.buf_count;
+ memcpy(rctx->buf, state.buf, sizeof(rctx->buf));

return 0;
}
diff --git a/drivers/crypto/ccp/ccp-crypto-sha.c b/drivers/crypto/ccp/ccp-crypto-sha.c
index a68aa4c..e9b199f 100644
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -197,14 +197,17 @@ static int ccp_sha_digest(struct ahash_request *req)
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 = out;
+ struct ccp_sha_exp_ctx state;

- state->type = rctx->type;
- state->msg_bits = rctx->msg_bits;
- state->first = rctx->first;
- memcpy(state->ctx, rctx->ctx, sizeof(state->ctx));
- state->buf_count = rctx->buf_count;
- memcpy(state->buf, rctx->buf, sizeof(state->buf));
+ state.type = rctx->type;
+ state.msg_bits = rctx->msg_bits;
+ state.first = rctx->first;
+ memcpy(state.ctx, rctx->ctx, sizeof(state.ctx));
+ state.buf_count = rctx->buf_count;
+ memcpy(state.buf, rctx->buf, sizeof(state.buf));
+
+ /* 'out' may not be aligned so memcpy from local variable */
+ memcpy(out, &state, sizeof(state));

return 0;
}
@@ -212,14 +215,17 @@ static int ccp_sha_export(struct ahash_request *req, void *out)
static int ccp_sha_import(struct ahash_request *req, const void *in)
{
struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req);
- const struct ccp_sha_exp_ctx *state = in;
-
- rctx->type = state->type;
- rctx->msg_bits = state->msg_bits;
- rctx->first = state->first;
- memcpy(rctx->ctx, state->ctx, sizeof(rctx->ctx));
- rctx->buf_count = state->buf_count;
- memcpy(rctx->buf, state->buf, sizeof(rctx->buf));
+ struct ccp_sha_exp_ctx state;
+
+ /* 'in' may not be aligned so memcpy to local variable */
+ memcpy(&state, in, sizeof(state));
+
+ rctx->type = state.type;
+ rctx->msg_bits = state.msg_bits;
+ rctx->first = state.first;
+ memcpy(rctx->ctx, state.ctx, sizeof(rctx->ctx));
+ rctx->buf_count = state.buf_count;
+ memcpy(rctx->buf, state.buf, sizeof(rctx->buf));

return 0;
}
--
2.7.4