[PATCH v3] drm/amdgpu: Fix the memory allocation issue in amdgpu_discovery_get_nps_info()

[Li Huafei]

Fix two issues with memory allocation in amdgpu_discovery_get_nps_info()
for mem_ranges:

 - Add a check for allocation failure to avoid dereferencing a null
   pointer.

 - As suggested by Christophe, use kvcalloc() for memory allocation,
   which checks for multiplication overflow.

Additionally, assign the output parameters nps_type and range_cnt after
the kvcalloc() call to prevent modifying the output parameters in case
of an error return.

Fixes: b194d21b9bcc ("drm/amdgpu: Use NPS ranges from discovery table")
Suggested-by: Christophe JAILLET <christophe.jaillet at wanadoo.fr>
Reviewed-by: Lijo Lazar <lijo.lazar at amd.com>
Signed-off-by: Li Huafei <lihuafei1 at huawei.com>
---
Changes in v3: 
 - As suggested by Christophe, replace kvzalloc() with kvcalloc()
 - Link to v2: https://lore.kernel.org/lkml/20241029101839.2605713-1-lihuafei1@huawei.com/

Changes in v2:
 - kvzalloc() call uses 'nps_info->v1.count' instead of '*range_cnt'
 - Link to v1: https://lore.kernel.org/lkml/20241028215933.2599271-1-lihuafei1@huawei.com/
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
index 4bd61c169ca8..620090f092ab 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
@@ -1757,11 +1757,13 @@ int amdgpu_discovery_get_nps_info(struct amdgpu_device *adev,
 
 	switch (le16_to_cpu(nps_info->v1.header.version_major)) {
 	case 1:
+		mem_ranges = kvcalloc(nps_info->v1.count,
+				      sizeof(struct amdgpu_gmc_memrange),
+				      GFP_KERNEL);
+		if (!mem_ranges)
+			return -ENOMEM;
 		*nps_type = nps_info->v1.nps_type;
 		*range_cnt = nps_info->v1.count;
-		mem_ranges = kvzalloc(
-			*range_cnt * sizeof(struct amdgpu_gmc_memrange),
-			GFP_KERNEL);
 		for (i = 0; i < *range_cnt; i++) {
 			mem_ranges[i].base_address =
 				nps_info->v1.instance_info[i].base_address;
-- 
2.25.1