Re: [PATCH 1/7] drm/amdgpu/mmhub2.0: add bounds checking for cid

[Lazar, Lijo]

On 05-Mar-26 3:57 AM, Alex Deucher wrote:

The value should never exceed the array size as those
are the only values the hardware is expected to return,
but add checks anyway.

Signed-off-by: Alex Deucher <alexander.deuc...@amd.com>
---
  drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c | 9 ++++++---
  1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c 
b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
index a0cc8e218ca1e..534cb4c544dc4 100644
--- a/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/mmhub_v2_0.c
@@ -154,14 +154,17 @@ mmhub_v2_0_print_l2_protection_fault_status(struct 
amdgpu_device *adev,
        switch (amdgpu_ip_version(adev, MMHUB_HWIP, 0)) {
        case IP_VERSION(2, 0, 0):
        case IP_VERSION(2, 0, 2):
-               mmhub_cid = mmhub_client_ids_navi1x[cid][rw];
+               mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_navi1x) ?

Does this introduce speculation and requirement to use array_index_nospec?

Thanks,
Lijo

+                       mmhub_client_ids_navi1x[cid][rw] : NULL;
                break;
        case IP_VERSION(2, 1, 0):
        case IP_VERSION(2, 1, 1):
-               mmhub_cid = mmhub_client_ids_sienna_cichlid[cid][rw];
+               mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_sienna_cichlid) ?
+                       mmhub_client_ids_sienna_cichlid[cid][rw] : NULL;
                break;
        case IP_VERSION(2, 1, 2):
-               mmhub_cid = mmhub_client_ids_beige_goby[cid][rw];
+               mmhub_cid = cid < ARRAY_SIZE(mmhub_client_ids_beige_goby) ?
+                       mmhub_client_ids_beige_goby[cid][rw] : NULL;
                break;
        default:
                mmhub_cid = NULL;