[PATCH 3.16 017/217] crypto: ccp - Don't assume export/import areas are aligned

[Ben Hutchings]

3.16.35-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Tom Lendacky <thomas.lenda...@amd.com>

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.lenda...@amd.com>
Signed-off-by: Herbert Xu <herb...@gondor.apana.org.au>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/crypto/ccp/ccp-crypto-aes-cmac.c | 26 ++++++++++++++---------
 drivers/crypto/ccp/ccp-crypto-sha.c      | 36 +++++++++++++++++++-------------
 2 files changed, 37 insertions(+), 25 deletions(-)

--- a/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-cmac.c
@@ -204,12 +204,15 @@ static int ccp_aes_cmac_digest(struct ah
 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;
 }
@@ -217,12 +220,15 @@ static int ccp_aes_cmac_export(struct ah
 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;
 }
--- a/drivers/crypto/ccp/ccp-crypto-sha.c
+++ b/drivers/crypto/ccp/ccp-crypto-sha.c
@@ -196,14 +196,17 @@ static int ccp_sha_digest(struct ahash_r
 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;
 }
@@ -211,14 +214,17 @@ static int ccp_sha_export(struct ahash_r
 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;
+       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));
+       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;
 }