drm/amdgpu: Fix the memory allocation issue in amdgpu_discovery_get_nps_info()

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 <[email protected]>
Reviewed-by: Lijo Lazar <[email protected]>
Signed-off-by: Li Huafei <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
index 73f4d56c5de4acc8f67b4ff7b043d62be19324b8..1040204ac8b97c6895fbe7b00e6fbc6d2532835b 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
@@ -1795,11 +1795,13 @@ 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(*mem_ranges),
+                                     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;