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| author | Xiaogang Chen <xiaogang.chen@amd.com> | 2026-05-26 22:50:02 -0500 |
|---|---|---|
| committer | Alex Deucher <alexander.deucher@amd.com> | 2026-06-17 18:24:38 -0400 |
| commit | 8242a8d9d7194d5ef8a8b38a5621ca0966a3ec15 (patch) | |
| tree | 4e466057ef6b96e7579085a9e4548fc7e9a97a06 /drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | |
| parent | 7152b248dc3c8d5fa8629e99ed5655dd41b51562 (diff) | |
| download | linux-next-8242a8d9d7194d5ef8a8b38a5621ca0966a3ec15.tar.gz linux-next-8242a8d9d7194d5ef8a8b38a5621ca0966a3ec15.zip | |
drm/amdkfd: Let driver decide buffer size at AMDKFD_IOC_GET_DMABUF_INFO ioctl
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>
(cherry picked from commit f54ce9e8cbd3abe0eda3a285f54dc4f572fe589a)
Diffstat (limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c')
| -rw-r--r-- | drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 23 |
1 files changed, 19 insertions, 4 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c index 9783a3cefb04..da325863ad76 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c @@ -558,7 +558,7 @@ uint32_t amdgpu_amdkfd_get_max_engine_clock_in_mhz(struct amdgpu_device *adev) int amdgpu_amdkfd_get_dmabuf_info(struct amdgpu_device *adev, int dma_buf_fd, struct amdgpu_device **dmabuf_adev, - uint64_t *bo_size, void *metadata_buffer, + uint64_t *bo_size, void **metadata_buffer, size_t buffer_size, uint32_t *metadata_size, uint32_t *flags, int8_t *xcp_id) { @@ -593,9 +593,24 @@ int amdgpu_amdkfd_get_dmabuf_info(struct amdgpu_device *adev, int dma_buf_fd, *dmabuf_adev = adev; if (bo_size) *bo_size = amdgpu_bo_size(bo); - if (metadata_buffer) - r = amdgpu_bo_get_metadata(bo, metadata_buffer, buffer_size, - metadata_size, &metadata_flags); + if (metadata_buffer) { + /* first get metadata_size by buffer = NULL */ + r = amdgpu_bo_get_metadata(bo, NULL, 0, + metadata_size, NULL); + + /* user buf_size is bigger than bo metadata_size + * allocate a buf at kernel space and copy */ + if (*metadata_size <= buffer_size) { + *metadata_buffer = kzalloc(*metadata_size, GFP_KERNEL); + + if (!*metadata_buffer) + return -ENOMEM; + + r = amdgpu_bo_get_metadata(bo, *metadata_buffer, *metadata_size, + NULL, &metadata_flags); + } else + r = -EINVAL; + } if (flags) { *flags = (bo->preferred_domains & AMDGPU_GEM_DOMAIN_VRAM) ? KFD_IOC_ALLOC_MEM_FLAGS_VRAM |