crypto: omap-aes - Remove VLA usage of skcipher

In the quest to remove all stack VLA usage from the kernel[1], this
replaces struct crypto_skcipher and SKCIPHER_REQUEST_ON_STACK() usage
with struct crypto_sync_skcipher and SYNC_SKCIPHER_REQUEST_ON_STACK(),
which uses a fixed stack size.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/omap-aes.c b/drivers/crypto/omap-aes.c
index 9019f6b..a553ffd 100644 (file)
--- a/drivers/crypto/omap-aes.c
+++ b/drivers/crypto/omap-aes.c
@@ -522,9 +522,9 @@ static int omap_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
                  !!(mode & FLAGS_CBC));
 
        if (req->nbytes < aes_fallback_sz) {
-               SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
+               SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
 
-               skcipher_request_set_tfm(subreq, ctx->fallback);
+               skcipher_request_set_sync_tfm(subreq, ctx->fallback);
                skcipher_request_set_callback(subreq, req->base.flags, NULL,
                                              NULL);
                skcipher_request_set_crypt(subreq, req->src, req->dst,
@@ -564,11 +564,11 @@ static int omap_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
        memcpy(ctx->key, key, keylen);
        ctx->keylen = keylen;
 
-       crypto_skcipher_clear_flags(ctx->fallback, CRYPTO_TFM_REQ_MASK);
-       crypto_skcipher_set_flags(ctx->fallback, tfm->base.crt_flags &
+       crypto_sync_skcipher_clear_flags(ctx->fallback, CRYPTO_TFM_REQ_MASK);
+       crypto_sync_skcipher_set_flags(ctx->fallback, tfm->base.crt_flags &
                                                 CRYPTO_TFM_REQ_MASK);
 
-       ret = crypto_skcipher_setkey(ctx->fallback, key, keylen);
+       ret = crypto_sync_skcipher_setkey(ctx->fallback, key, keylen);
        if (!ret)
                return 0;
 
@@ -613,11 +613,10 @@ static int omap_aes_crypt_req(struct crypto_engine *engine,
 static int omap_aes_cra_init(struct crypto_tfm *tfm)
 {
        const char *name = crypto_tfm_alg_name(tfm);
-       const u32 flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK;
        struct omap_aes_ctx *ctx = crypto_tfm_ctx(tfm);
-       struct crypto_skcipher *blk;
+       struct crypto_sync_skcipher *blk;
 
-       blk = crypto_alloc_skcipher(name, 0, flags);
+       blk = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);
        if (IS_ERR(blk))
                return PTR_ERR(blk);
 
@@ -667,7 +666,7 @@ static void omap_aes_cra_exit(struct crypto_tfm *tfm)
        struct omap_aes_ctx *ctx = crypto_tfm_ctx(tfm);
 
        if (ctx->fallback)
-               crypto_free_skcipher(ctx->fallback);
+               crypto_free_sync_skcipher(ctx->fallback);
 
        ctx->fallback = NULL;
 }

diff --git a/drivers/crypto/omap-aes.h b/drivers/crypto/omap-aes.h
index fc3b46a..7e02920 100644 (file)
--- a/drivers/crypto/omap-aes.h
+++ b/drivers/crypto/omap-aes.h
@@ -101,7 +101,7 @@ struct omap_aes_ctx {
        int             keylen;
        u32             key[AES_KEYSIZE_256 / sizeof(u32)];
        u8              nonce[4];
-       struct crypto_skcipher  *fallback;
+       struct crypto_sync_skcipher     *fallback;
        struct crypto_skcipher  *ctr;
 };