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=qpxydaacu1rq...@mail.gmail.com Signed-off-by: Kees Cook <keesc...@chromium.org> --- crypto/cryptd.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/crypto/cryptd.c b/crypto/cryptd.c index addca7bae33f..7118fb5efbaa 100644 --- a/crypto/cryptd.c +++ b/crypto/cryptd.c @@ -76,7 +76,7 @@ struct cryptd_blkcipher_request_ctx { 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 @@ static int cryptd_skcipher_setkey(struct crypto_skcipher *parent, 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 @@ static void cryptd_skcipher_encrypt(struct crypto_async_request *base, 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 @@ static void cryptd_skcipher_decrypt(struct crypto_async_request *base, 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 @@ static int cryptd_skcipher_init_tfm(struct crypto_skcipher *tfm) 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 @@ static void cryptd_skcipher_exit_tfm(struct crypto_skcipher *tfm) { 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 crypto_skcipher *cryptd_skcipher_child(struct cryptd_skcipher *tfm) { struct cryptd_skcipher_ctx *ctx = crypto_skcipher_ctx(&tfm->base); - return ctx->child; + return &ctx->child->base; } EXPORT_SYMBOL_GPL(cryptd_skcipher_child); -- 2.17.1
