On Tue, Mar 28, 2023 at 5:58 AM Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote:
>
> Allocating the hash state on the stack limits its size. Change
> this to use kmalloc so the limit can be removed for new drivers.
>
> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
>
> diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
> index 1d017ec5c63c..63af72e19fa8 100644
> --- a/crypto/algif_hash.c
> +++ b/crypto/algif_hash.c
> @@ -235,24 +235,31 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
> struct alg_sock *ask = alg_sk(sk);
> struct hash_ctx *ctx = ask->private;
> struct ahash_request *req = &ctx->req;
> - char state[HASH_MAX_STATESIZE];
> + struct crypto_ahash *tfm;
> struct sock *sk2;
> struct alg_sock *ask2;
> struct hash_ctx *ctx2;
> + char *state;
> bool more;
> int err;
>
> + tfm = crypto_ahash_reqtfm(req);
> + state = kmalloc(crypto_ahash_statesize(tfm), GFP_KERNEL);
Shouldn't sock_kmalloc() be used instead?
> + err = -ENOMEM;
> + if (!state)
> + goto out;
> +
> lock_sock(sk);
> more = ctx->more;
> err = more ? crypto_ahash_export(req, state) : 0;
> release_sock(sk);
>
> if (err)
> - return err;
> + goto out_free_state;
>
> err = af_alg_accept(ask->parent, newsock, kern);
> if (err)
> - return err;
> + goto out_free_state;
>
> sk2 = newsock->sk;
> ask2 = alg_sk(sk2);
> @@ -260,7 +267,7 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
> ctx2->more = more;
>
> if (!more)
> - return err;
> + goto out_free_state;
>
> err = crypto_ahash_import(&ctx2->req, state);
> if (err) {
> @@ -268,6 +275,10 @@ static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
> sock_put(sk2);
> }
>
> +out_free_state:
> + kfree_sensitive(state);
> +
> +out:
> return err;
> }
>
> --
> Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Home Page: http://gondor.apana.org.au/~herbert/
> PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
