crypto: cryptd - 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/cryptd.c b/crypto/cryptd.c
index addca7b..7118fb5e 100644
--- a/crypto/cryptd.c
+++ b/crypto/cryptd.c
@@ -76,7 +76,7 @@
struct cryptd_skcipher_ctx {
atomic_t refcnt;
- struct crypto_skcipher *child;
+ struct crypto_sync_skcipher *child;
};
struct cryptd_skcipher_request_ctx {
@@ -449,14 +449,16 @@
const u8 *key, unsigned int keylen)
{
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(parent);
- struct crypto_skcipher *child = ctx->child;
+ struct crypto_sync_skcipher *child = ctx->child;
int err;
- crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
- crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
+ crypto_sync_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
+ crypto_sync_skcipher_set_flags(child,
+ crypto_skcipher_get_flags(parent) &
CRYPTO_TFM_REQ_MASK);
- err = crypto_skcipher_setkey(child, key, keylen);
- crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
+ err = crypto_sync_skcipher_setkey(child, key, keylen);
+ crypto_skcipher_set_flags(parent,
+ crypto_sync_skcipher_get_flags(child) &
CRYPTO_TFM_RES_MASK);
return err;
}
@@ -483,13 +485,13 @@
struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
- struct crypto_skcipher *child = ctx->child;
- SKCIPHER_REQUEST_ON_STACK(subreq, child);
+ struct crypto_sync_skcipher *child = ctx->child;
+ SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, child);
if (unlikely(err == -EINPROGRESS))
goto out;
- skcipher_request_set_tfm(subreq, child);
+ skcipher_request_set_sync_tfm(subreq, child);
skcipher_request_set_callback(subreq, CRYPTO_TFM_REQ_MAY_SLEEP,
NULL, NULL);
skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
@@ -511,13 +513,13 @@
struct cryptd_skcipher_request_ctx *rctx = skcipher_request_ctx(req);
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
- struct crypto_skcipher *child = ctx->child;
- SKCIPHER_REQUEST_ON_STACK(subreq, child);
+ struct crypto_sync_skcipher *child = ctx->child;
+ SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, child);
if (unlikely(err == -EINPROGRESS))
goto out;
- skcipher_request_set_tfm(subreq, child);
+ skcipher_request_set_sync_tfm(subreq, child);
skcipher_request_set_callback(subreq, CRYPTO_TFM_REQ_MAY_SLEEP,
NULL, NULL);
skcipher_request_set_crypt(subreq, req->src, req->dst, req->cryptlen,
@@ -568,7 +570,7 @@
if (IS_ERR(cipher))
return PTR_ERR(cipher);
- ctx->child = cipher;
+ ctx->child = (struct crypto_sync_skcipher *)cipher;
crypto_skcipher_set_reqsize(
tfm, sizeof(struct cryptd_skcipher_request_ctx));
return 0;
@@ -578,7 +580,7 @@
{
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
- crypto_free_skcipher(ctx->child);
+ crypto_free_sync_skcipher(ctx->child);
}
static void cryptd_skcipher_free(struct skcipher_instance *inst)
@@ -1243,7 +1245,7 @@
{
struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base);
- return ctx->child;
+ return &ctx->child->base;
}
EXPORT_SYMBOL_GPL(cryptd_skcipher_child);