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References: <20231129152212.7879-1-n.zhandarovich@fintech.ru>
In-Reply-To: <20231129152212.7879-1-n.zhandarovich@fintech.ru>
From:   Alex Deucher <alexdeucher@gmail.com>
Date:   Thu, 30 Nov 2023 12:10:39 -0500
Message-ID: <CADnq5_MZSG=g9UiYxWd0dAoqrkA7Bj-yVK0ExSMpsrcj8ML00A@mail.gmail.com>
Subject: Re: [PATCH] drm/radeon/r100: Fix integer overflow issues in r100_cs_track_check()
To:     Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Cc:     Alex Deucher <alexander.deucher@amd.com>,
        =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>,
        "Pan, Xinhui" <Xinhui.Pan@amd.com>, linux-kernel@vger.kernel.org,
        amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org
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Applied.  Thanks!

On Wed, Nov 29, 2023 at 10:28=E2=80=AFAM Nikita Zhandarovich
<n.zhandarovich@fintech.ru> wrote:
>
> It may be possible, albeit unlikely, to encounter integer overflow
> during the multiplication of several unsigned int variables, the
> result being assigned to a variable 'size' of wider type.
>
> Prevent this potential behaviour by converting one of the multiples
> to unsigned long.
>
> Found by Linux Verification Center (linuxtesting.org) with static
> analysis tool SVACE.
>
> Fixes: 0242f74d29df ("drm/radeon: clean up CS functions in r100.c")
> Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
> ---
>  drivers/gpu/drm/radeon/r100.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.=
c
> index affa9e0309b2..cfeca2694d5f 100644
> --- a/drivers/gpu/drm/radeon/r100.c
> +++ b/drivers/gpu/drm/radeon/r100.c
> @@ -2321,7 +2321,7 @@ int r100_cs_track_check(struct radeon_device *rdev,=
 struct r100_cs_track *track)
>         switch (prim_walk) {
>         case 1:
>                 for (i =3D 0; i < track->num_arrays; i++) {
> -                       size =3D track->arrays[i].esize * track->max_indx=
 * 4;
> +                       size =3D track->arrays[i].esize * track->max_indx=
 * 4UL;
>                         if (track->arrays[i].robj =3D=3D NULL) {
>                                 DRM_ERROR("(PW %u) Vertex array %u no buf=
fer "
>                                           "bound\n", prim_walk, i);
> @@ -2340,7 +2340,7 @@ int r100_cs_track_check(struct radeon_device *rdev,=
 struct r100_cs_track *track)
>                 break;
>         case 2:
>                 for (i =3D 0; i < track->num_arrays; i++) {
> -                       size =3D track->arrays[i].esize * (nverts - 1) * =
4;
> +                       size =3D track->arrays[i].esize * (nverts - 1) * =
4UL;
>                         if (track->arrays[i].robj =3D=3D NULL) {
>                                 DRM_ERROR("(PW %u) Vertex array %u no buf=
fer "
>                                           "bound\n", prim_walk, i);
> --
> 2.25.1
>