[PATCH] drm/amdgpu: Fix out-of-bounds write warning

[Ma, Jun]

On 4/25/2024 8:39 PM, Christian König wrote:
> 
> 
> Am 25.04.24 um 12:00 schrieb Ma Jun:
>> Check the ring type value to fix the out-of-bounds
>> write warning
>>
>> Signed-off-by: Ma Jun <Jun.Ma2 at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> index 06f0a6534a94..1e0b5bb47bc9 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ring.c
>> @@ -353,6 +353,11 @@ int amdgpu_ring_init(struct amdgpu_device *adev, struct amdgpu_ring *ring,
>>   	ring->hw_prio = hw_prio;
>>   
>>   	if (!ring->no_scheduler) {
>> +		if (ring->funcs->type >= AMDGPU_HW_IP_NUM) {
>> +			dev_warn(adev->dev, "ring type %d has no scheduler\n", ring->funcs->type);
>> +			return 0;
>> +		}
>> +
> 
> That check should probably be at the beginning of the function since 
> trying to initialize a ring with an invalid type should be rejected 
> immediately.
> 
This check is used to skip the gpu_sched setting for the rings
which don't have scheduler, such as KIQ, MES, UMSCH_MM. 
Without this check, there could be an potential out-of-bounds writing
when ring->no__scheduler is not set correctly.

Regards,
Ma Jun

> Regards,
> Christian.
> 
>>   		hw_ip = ring->funcs->type;
>>   		num_sched = &adev->gpu_sched[hw_ip][hw_prio].num_scheds;
>>   		adev->gpu_sched[hw_ip][hw_prio].sched[(*num_sched)++] =
>