drm/amdkfd: Clear VRAM on allocation to prevent stale data exposure

commit ad52d61 upstream.

KFD VRAM allocations set AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE
but not AMDGPU_GEM_CREATE_VRAM_CLEARED, leaving freshly allocated
VRAM with stale data from prior use observable by compute kernels.

The GEM ioctl path already sets VRAM_CLEARED for all userspace
allocations via amdgpu_gem_create_ioctl() and
amdgpu_mode_dumb_create(). The KFD path was missing this flag,
allowing stale page table remnants to leak into user buffers.

This causes crashes in RCCL P2P transport where non-zero data in
ptrExchange/head/tail fields corrupts the protocol handshake.

Signed-off-by: Amir Shetaia <Amir.Shetaia@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: ashetaia-amd

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c

@@ -1665,7 +1665,8 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
 			alloc_domain = AMDGPU_GEM_DOMAIN_GTT;
 			alloc_flags = 0;
 		} else {
-			alloc_flags = AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE;
+			alloc_flags = AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE |
+				AMDGPU_GEM_CREATE_VRAM_CLEARED;
 			alloc_flags |= (flags & KFD_IOC_ALLOC_MEM_FLAGS_PUBLIC) ?
 			AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED : 0;
 		}