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From:   Karol Herbst <kherbst@redhat.com>
Date:   Sat, 13 Nov 2021 21:21:47 +0100
Message-ID: <CACO55tuDQ9UC2rr=_Hsowvujk49oNK1zWfHj3jMnhEqsTAnh0Q@mail.gmail.com>
Subject: Re: [PATCH] drm/nouveau/core: fix the uninitialized use in nvkm_ioctl_map()
To:     Yizhuo Zhai <yzhai003@ucr.edu>
Cc:     Ben Skeggs <bskeggs@redhat.com>, David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        nouveau <nouveau@lists.freedesktop.org>,
        LKML <linux-kernel@vger.kernel.org>
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something seems to have messed with the patch so it doesn't apply correctly.

On Thu, Jun 17, 2021 at 9:39 AM Yizhuo Zhai <yzhai003@ucr.edu> wrote:
>
> In function nvkm_ioctl_map(), the variable "type" could be
> uninitialized if "nvkm_object_map()" returns error code,
> however, it does not check the return value and directly
> use the "type" in the if statement, which is potentially
> unsafe.
>
> Signed-off-by: Yizhuo <yzhai003@ucr.edu>
> ---
>  drivers/gpu/drm/nouveau/nvkm/core/ioctl.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/nouveau/nvkm/core/ioctl.c
> b/drivers/gpu/drm/nouveau/nvkm/core/ioctl.c
> index d777df5a64e6..7f2e8482f167 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/core/ioctl.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/core/ioctl.c
> @@ -266,6 +266,8 @@ nvkm_ioctl_map(struct nvkm_client *client,
>                 ret = nvkm_object_map(object, data, size, &type,
>                                       &args->v0.handle,
>                                       &args->v0.length);
> +               if (ret)
> +                       return ret;
>                 if (type == NVKM_OBJECT_MAP_IO)
>                         args->v0.type = NVIF_IOCTL_MAP_V0_IO;
>                 else
> --
> 2.17.1
>