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

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
This commit is contained in:
Amir Shetaia
2026-04-10 10:38:13 -04:00
committed by Alex Deucher
parent 08cdf07b55
commit ad52d61d82

View File

@@ -1735,7 +1735,8 @@ 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;