crypto: ccm - move cbcmac input off the stack

Ard Biesheuvel · herbertx · commit 3b30460c5b0e · 2017-02-28T17:29:17.000+08:00
Commit f15f05b ("crypto: ccm - switch to separate cbcmac driver") refactored the CCM driver to allow separate implementations of the underlying MAC to be provided by a platform. However, in doing so, it moved some data from the linear region to the stack, which violates the SG constraints when the stack is virtually mapped. So move idata/odata back to the request ctx struct, of which we can reasonably expect that it has been allocated using kmalloc() et al. Reported-by: Johannes Berg <johannes@sipsolutions.net> Fixes: f15f05b ("crypto: ccm - switch to separate cbcmac driver") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/ccm.c b/crypto/ccm.c
@@ -45,6 +45,7 @@ struct crypto_rfc4309_req_ctx {
 
 struct crypto_ccm_req_priv_ctx {
 	u8 odata[16];
+	u8 idata[16];
 	u8 auth_tag[16];
 	u32 flags;
 	struct scatterlist src[3];
@@ -183,8 +184,8 @@ static int crypto_ccm_auth(struct aead_request *req, struct scatterlist *plain,
 	AHASH_REQUEST_ON_STACK(ahreq, ctx->mac);
 	unsigned int assoclen = req->assoclen;
 	struct scatterlist sg[3];
-	u8 odata[16];
-	u8 idata[16];
+	u8 *odata = pctx->odata;
+	u8 *idata = pctx->idata;
 	int ilen, err;
 
 	/* format control data for input */
