crypto: ccm - Remove VLA usage (ebf533ad) · Commits · 戴 / test

In the quest to remove all stack VLA usage from the kernel[1], this drops AHASH_REQUEST_ON_STACK by preallocating the ahash request area combined with the skcipher area (which are not used at the same time). [1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com Signed-off-by:

crypto/ccm.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -50,8 +50,11 @@ struct crypto_ccm_req_priv_ctx {
		u32 flags;
		struct scatterlist src[3];
		struct scatterlist dst[3];
		union {
		struct ahash_request ahreq;
		struct skcipher_request skreq;
		};
		};

		struct cbcmac_tfm_ctx {
		struct crypto_cipher *child;
		@@ -181,7 +184,7 @@ static int crypto_ccm_auth(struct aead_request req, struct scatterlist plain,
		struct crypto_ccm_req_priv_ctx *pctx = crypto_ccm_reqctx(req);
		struct crypto_aead *aead = crypto_aead_reqtfm(req);
		struct crypto_ccm_ctx *ctx = crypto_aead_ctx(aead);
		AHASH_REQUEST_ON_STACK(ahreq, ctx->mac);
		struct ahash_request *ahreq = &pctx->ahreq;
		unsigned int assoclen = req->assoclen;
		struct scatterlist sg[3];
		u8 *odata = pctx->odata;
		@@ -427,7 +430,7 @@ static int crypto_ccm_init_tfm(struct crypto_aead *tfm)
		crypto_aead_set_reqsize(
		tfm,
		align + sizeof(struct crypto_ccm_req_priv_ctx) +
		crypto_skcipher_reqsize(ctr));
		max(crypto_ahash_reqsize(mac), crypto_skcipher_reqsize(ctr)));

		return 0;