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From:   Dongliang Mu <mudongliangabcd@gmail.com>
Date:   Mon, 26 Jul 2021 23:31:34 +0800
Message-ID: <CAD-N9QV68AUo9MRXkRBOu950BdfoaWUaNSX9jfxhz5Qkpc4LMQ@mail.gmail.com>
Subject: Re: [PATCH v4] crypto: sun8i-ss: fix multiple memory leaks in sun8i_ss_hash_run
To:     Corentin Labbe <clabbe.montjoie@gmail.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Maxime Ripard <mripard@kernel.org>,
        Chen-Yu Tsai <wens@csie.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Ard Biesheuvel <ardb@kernel.org>,
        Xiang Chen <chenxiang66@hisilicon.com>,
        Eric Biggers <ebiggers@google.com>,
        Dongliang Mu <mudongliangabcd@gmail.com>,
        Colin Ian King <colin.king@canonical.com>
Cc:     linux-crypto@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-sunxi@lists.linux.dev,
        linux-kernel <linux-kernel@vger.kernel.org>
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Precedence: bulk

On Mon, Jul 26, 2021 at 11:25 PM Dongliang Mu <mudongliangabcd@gmail.com> wrote:
>
> In sun8i_ss_hash_run, all the dma_mmap_sg/single will cause memory leak
> due to no corresponding unmap operation if errors happen.
>
> Fix this by adding error handling part for all the dma_mmap_sg/single.
>
> Fixes: d9b45418a917 ("crypto: sun8i-ss - support hash algorithms")
> Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
> ---
> v1->v2: move crypto_finalize_hash_request to the end of function; move
> the memcpy after the dma_mmap_sg/single functions.
> v2->v3: remove some unrelated code changes; delete the fix of return value
> since there is no corresponding handling code
> v3->v4: change sun8i_ce to sun8i_ss

From v3 to v4, I changed the title and commit message from sun8i_ce to
sun8i_ss because I suddenly realized that the code change below is for
sun8i_ss_hash_run, other than sun8i_ce_hash_run.

Furthermore, sun8i_ce is also prone to this issue. I've sent another
patch to fix it.

>  drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
> index 3c073eb3db03..5448705e8ae1 100644
> --- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
> +++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
> @@ -368,14 +368,14 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
>         if (nr_sgs <= 0 || nr_sgs > MAX_SG) {
>                 dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);
>                 err = -EINVAL;
> -               goto theend;
> +               goto err_result;
>         }
>
>         addr_res = dma_map_single(ss->dev, result, digestsize, DMA_FROM_DEVICE);
>         if (dma_mapping_error(ss->dev, addr_res)) {
>                 dev_err(ss->dev, "DMA map dest\n");
>                 err = -EINVAL;
> -               goto theend;
> +               goto err_unmap_sg;
>         }
>
>         len = areq->nbytes;
> @@ -390,7 +390,7 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
>         if (len > 0) {
>                 dev_err(ss->dev, "remaining len %d\n", len);
>                 err = -EINVAL;
> -               goto theend;
> +               goto err_addr_res;
>         }
>
>         byte_count = areq->nbytes;
> @@ -428,18 +428,19 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
>         if (dma_mapping_error(ss->dev, addr_pad)) {
>                 dev_err(ss->dev, "DMA error on padding SG\n");
>                 err = -EINVAL;
> -               goto theend;
> +               goto err_addr_res;
>         }
>
>         err = sun8i_ss_run_hash_task(ss, rctx, crypto_tfm_alg_name(areq->base.tfm));
>
>         dma_unmap_single(ss->dev, addr_pad, j * 4, DMA_TO_DEVICE);
> +err_addr_res:
> +       dma_unmap_single(ss->dev, addr_res, digestsize, DMA_FROM_DEVICE);
> +err_unmap_sg:
>         dma_unmap_sg(ss->dev, areq->src, sg_nents(areq->src),
>                      DMA_TO_DEVICE);
> -       dma_unmap_single(ss->dev, addr_res, digestsize, DMA_FROM_DEVICE);
> -
>         memcpy(areq->result, result, algt->alg.hash.halg.digestsize);
> -theend:
> +err_result:
>         kfree(pad);
>         kfree(result);
>         crypto_finalize_hash_request(engine, breq, err);
> --
> 2.25.1
>