drm/amdkfd: Let driver decide buffer size at AMDKFD_IOC_GET_DMABUF_INFO ioctl

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amdkfd driver needs allocate buffer to return bo metadata to user space. The
buffer size is controlled by user currently. It is a potential security issue
that hostile value (e.g. 2 GiB) lets any render-group user trigger order-MAX
allocation/OOM in kernel context.

This patch first finds bo metadata size. If the size is smaller than user
provided value drive can safely allocate buffer in kernel space and copy to
user space buffer. If not, driver will let user know, not allocate and copy.
User will redo with new buffer in user space.

This patch lets driver decide buffer allocation size to avoid potential hostile
size from user space.

Signed-off-by: Xiaogang Chen <xiaogang.chen@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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Xiaogang Chen 2026-05-26 22:50:02 -05:00 • committed by Alex Deucher

parent 7de02fe953

commit f54ce9e8cb

3 changed files with 22 additions and 13 deletions

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23

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

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2

drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h

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10

drivers/gpu/drm/amd/amdkfd/kfd_chardev.c

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