crypto: atmel-sha - fix race in atmel_sha_final()

When (!ctx->bufcnt && !(ctx->flags & SHA_FLAGS_PAD)), the former source
code used to set the SHA_FLAGS_BUSY without checking whether this flag was
already set. If so, the hardware is already processing another hash
request so the processing of the req argument of atmel_sha_final() should
be delayed by queueing this request, the same way as done for the
(ctx->bufcnt != 0) case.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Cyrille Pitchen 2016-02-08 16:26:49 +01:00 committed by Herbert Xu
parent 9c4274d90d
commit ad84112a11

View File

@ -979,37 +979,17 @@ static int atmel_sha_update(struct ahash_request *req)
static int atmel_sha_final(struct ahash_request *req)
{
struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
struct atmel_sha_ctx *tctx = crypto_tfm_ctx(req->base.tfm);
struct atmel_sha_dev *dd = tctx->dd;
int err = 0;
ctx->flags |= SHA_FLAGS_FINUP;
if (ctx->flags & SHA_FLAGS_ERROR)
return 0; /* uncompleted hash is not needed */
if (ctx->bufcnt) {
return atmel_sha_enqueue(req, SHA_OP_FINAL);
} else if (!(ctx->flags & SHA_FLAGS_PAD)) { /* add padding */
err = atmel_sha_hw_init(dd);
if (err)
goto err1;
dd->req = req;
dd->flags |= SHA_FLAGS_BUSY;
err = atmel_sha_final_req(dd);
} else {
if (ctx->flags & SHA_FLAGS_PAD)
/* copy ready hash (+ finalize hmac) */
return atmel_sha_finish(req);
}
err1:
if (err != -EINPROGRESS)
/* done_task will not finish it, so do it here */
atmel_sha_finish_req(req, err);
return err;
return atmel_sha_enqueue(req, SHA_OP_FINAL);
}
static int atmel_sha_finup(struct ahash_request *req)