drm/amd/display: Use kmalloc_array() instead of kmalloc()

Documentation/process/deprecated.rst recommends against the use of kmalloc
with dynamic size calculations due to the risk of overflow and smaller
allocation being made than the caller was expecting. This could lead to
buffer overflow in code similar to the memcpy in
amdgpu_dm_plane_add_modifier().

Signed-off-by: James Flowers <bold.zone2373@fastmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: James Flowers

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_plane.c

@@ -146,7 +146,7 @@ static void amdgpu_dm_plane_add_modifier(uint64_t **mods, uint64_t *size, uint64
 
 	if (*cap - *size < 1) {
 		uint64_t new_cap = *cap * 2;
-		uint64_t *new_mods = kmalloc(new_cap * sizeof(uint64_t), GFP_KERNEL);
+		uint64_t *new_mods = kmalloc_array(new_cap, sizeof(uint64_t), GFP_KERNEL);
 
 		if (!new_mods) {
 			kfree(*mods);
@@ -732,7 +732,7 @@ static int amdgpu_dm_plane_get_plane_modifiers(struct amdgpu_device *adev, unsig
 	if (adev->family < AMDGPU_FAMILY_AI)
 		return 0;
 
-	*mods = kmalloc(capacity * sizeof(uint64_t), GFP_KERNEL);
+	*mods = kmalloc_array(capacity, sizeof(uint64_t), GFP_KERNEL);
 
 	if (plane_type == DRM_PLANE_TYPE_CURSOR) {
 		amdgpu_dm_plane_add_modifier(mods, &size, &capacity, DRM_FORMAT_MOD_LINEAR);