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

Commit Message

[e-mail] Dec. 20, 2023, 2:46 a.m. UTC

From: Yang Guang <[e-mail]>

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 <[e-mail]>
---
 drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

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];