crypto: null - 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/crypto/crypto_null.c b/crypto/crypto_null.c
index 0959b26..0bae599 100644
--- a/crypto/crypto_null.c
+++ b/crypto/crypto_null.c
@@ -26,7 +26,7 @@
#include <linux/string.h>
static DEFINE_MUTEX(crypto_default_null_skcipher_lock);
-static struct crypto_skcipher *crypto_default_null_skcipher;
+static struct crypto_sync_skcipher *crypto_default_null_skcipher;
static int crypto_default_null_skcipher_refcnt;
static int null_compress(struct crypto_tfm *tfm, const u8 *src,
@@ -152,16 +152,15 @@ MODULE_ALIAS_CRYPTO("compress_null");
MODULE_ALIAS_CRYPTO("digest_null");
MODULE_ALIAS_CRYPTO("cipher_null");
-struct crypto_skcipher *crypto_get_default_null_skcipher(void)
+struct crypto_sync_skcipher *crypto_get_default_null_skcipher(void)
{
- struct crypto_skcipher *tfm;
+ struct crypto_sync_skcipher *tfm;
mutex_lock(&crypto_default_null_skcipher_lock);
tfm = crypto_default_null_skcipher;
if (!tfm) {
- tfm = crypto_alloc_skcipher("ecb(cipher_null)",
- 0, CRYPTO_ALG_ASYNC);
+ tfm = crypto_alloc_sync_skcipher("ecb(cipher_null)", 0, 0);
if (IS_ERR(tfm))
goto unlock;
@@ -181,7 +180,7 @@ void crypto_put_default_null_skcipher(void)
{
mutex_lock(&crypto_default_null_skcipher_lock);
if (!--crypto_default_null_skcipher_refcnt) {
- crypto_free_skcipher(crypto_default_null_skcipher);
+ crypto_free_sync_skcipher(crypto_default_null_skcipher);
crypto_default_null_skcipher = NULL;
}
mutex_unlock(&crypto_default_null_skcipher_lock);