From ad52d61d82181dbdb7f05826de38352d5e550cc2 Mon Sep 17 00:00:00 2001 From: Amir Shetaia Date: Fri, 10 Apr 2026 10:38:13 -0400 Subject: [PATCH] drm/amdkfd: Clear VRAM on allocation to prevent stale data exposure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Christian König Signed-off-by: Alex Deucher Cc: stable@vger.kernel.org --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c index 29b400cdd6d5..72a5a29e63f6 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c @@ -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;