Re: [PATCH v3 4/4] crypto: starfive - Add hash and HMAC support

[Herbert Xu]

On Mon, Mar 13, 2023 at 09:56:46PM +0800, Jia Jie Ho wrote:
>
> +static int starfive_hash_copy_sgs(struct starfive_cryp_request_ctx *rctx)
> +{
> +	void *buf_in;
> +	int pages, total_in;
> +
> +	if (!starfive_hash_check_io_aligned(rctx)) {
> +		rctx->sgs_copied = 0;
> +		return 0;
> +	}
> +
> +	total_in = ALIGN(rctx->total, rctx->blksize);
> +	pages = total_in ? get_order(total_in) : 1;
> +	buf_in = (void *)__get_free_pages(GFP_ATOMIC, pages);

Please don't allocate the whole thing because it could be unlimited
in size (and triggered from user-space by untrusted users too).

If you have to copy, then just allocate a single page and copy
that, hash, and then repeat until it's all done.

Cheers,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt