[PATCH linux-next] drm/amd/display: use kcalloc instead of open coded arithmetic

From: yang.guang5
Date: Tue Dec 19 2023 - 21:47:21 EST


From: Yang Guang <yang.guang5@xxxxxxxxxx>

Dynamic size calculations (especially multiplication) should not be
performed in memory allocator (or similar) function arguments due
to the risk of them overflowing. This could lead to values wrapping
around and a smaller allocation being made than the caller was
expecting. Using those allocations could lead to linear overflows
of heap memory and other misbehaviors.

Signed-off-by: Chen Haonan <chen.haonan2@xxxxxxxxxx>
---
drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index d7ac020bd8af..d6d63bd7482e 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -9204,7 +9204,7 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
* Here we create an empty update on each plane.
* To fix this, DC should permit updating only stream properties.
*/
- dummy_updates = kzalloc(sizeof(struct dc_surface_update) * MAX_SURFACES, GFP_ATOMIC);
+ dummy_updates = kcalloc(MAX_SURFACES, sizeof(struct dc_surface_update), GFP_ATOMIC);
for (j = 0; j < status->plane_count; j++)
dummy_updates[j].surface = status->plane_states[0];

--
2.25.1