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SubjectRe: [PATCH v4 3/3] crypto: Add Allwinner Security System crypto accelerator
On Sat, Jul 12, 2014 at 02:59:13PM +0200, LABBE Corentin wrote:
>
> +/* sunxi_hash_init: initialize request context
> + * Activate the SS, and configure it for MD5 or SHA1
> + */
> +int sunxi_hash_init(struct ahash_request *areq)
> +{
> + const char *hash_type;
> + struct crypto_ahash *tfm = crypto_ahash_reqtfm(areq);
> + struct sunxi_req_ctx *op = crypto_ahash_ctx(tfm);
> +
> + mutex_lock(&ss->lock);
> +
> + hash_type = crypto_tfm_alg_name(areq->base.tfm);
> +
> + op->byte_count = 0;
> + op->nbwait = 0;
> + op->waitbuf = 0;
> +
> + /* Enable and configure SS for MD5 or SHA1 */
> + if (strcmp(hash_type, "sha1") == 0)
> + op->mode = SS_OP_SHA1;
> + else
> + op->mode = SS_OP_MD5;
> +
> + writel(op->mode | SS_ENABLED, ss->base + SS_CTL);
> + return 0;

The hash driver is completely broken. You are modifying tfm
ctx data which is shared by all users of a single tfm. So
if two users conduct hashes in parallel they will step all
over each other.

Worse, the unpaired mutex_lock will quickly lead to dead locks.

You cannot assume that final will be called.

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


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