2023-11-29 15:22:31

by Nikita Zhandarovich

Subject: [PATCH] drm/radeon/r100: Fix integer overflow issues in r100_cs_track_check()

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 <[email protected]>
---
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 = 0; i < track->num_arrays; i++) {
- size = track->arrays[i].esize * track->max_indx * 4;
+ size = track->arrays[i].esize * track->max_indx * 4UL;
if (track->arrays[i].robj == NULL) {
DRM_ERROR("(PW %u) Vertex array %u no buffer "
"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 = 0; i < track->num_arrays; i++) {
- size = track->arrays[i].esize * (nverts - 1) * 4;
+ size = track->arrays[i].esize * (nverts - 1) * 4UL;
if (track->arrays[i].robj == NULL) {
DRM_ERROR("(PW %u) Vertex array %u no buffer "
"bound\n", prim_walk, i);
--
2.25.1

2023-11-30 17:11:19

by Alex Deucher

Subject: Re: [PATCH] drm/radeon/r100: Fix integer overflow issues in r100_cs_track_check()

Applied. Thanks!

On Wed, Nov 29, 2023 at 10:28 AM Nikita Zhandarovich
<[email protected]> 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 <[email protected]>
> ---
> 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 = 0; i < track->num_arrays; i++) {
> - size = track->arrays[i].esize * track->max_indx * 4;
> + size = track->arrays[i].esize * track->max_indx * 4UL;
> if (track->arrays[i].robj == NULL) {
> DRM_ERROR("(PW %u) Vertex array %u no buffer "
> "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 = 0; i < track->num_arrays; i++) {
> - size = track->arrays[i].esize * (nverts - 1) * 4;
> + size = track->arrays[i].esize * (nverts - 1) * 4UL;
> if (track->arrays[i].robj == NULL) {
> DRM_ERROR("(PW %u) Vertex array %u no buffer "
> "bound\n", prim_walk, i);
> --
> 2.25.1
>