github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-09-22 04:34:03 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

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

Browse Source 
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>
This commit is contained in:
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
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
View File

@ -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

2
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
View File

@ -268,7 +268,7 @@ uint64_t amdgpu_amdkfd_get_gpu_clock_counter(struct amdgpu_device *adev);
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);
int amdgpu_amdkfd_get_pcie_bandwidth_mbytes(struct amdgpu_device *adev, bool is_min);

10
drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
View File

@ -1562,16 +1562,10 @@ static int kfd_ioctl_get_dmabuf_info(struct file *filep,
if (!dev)
return -EINVAL;
if (args->metadata_ptr) {
metadata_buffer = kzalloc(args->metadata_size, GFP_KERNEL);
if (!metadata_buffer)
return -ENOMEM;
}
/* Get dmabuf info from KGD */
r = amdgpu_amdkfd_get_dmabuf_info(dev->adev, args->dmabuf_fd,
&dmabuf_adev, &args->size,
metadata_buffer, args->metadata_size,
&metadata_buffer, args->metadata_size,
&args->metadata_size, &flags, &xcp_id);
if (r)
goto exit;
@ -1583,7 +1577,7 @@ static int kfd_ioctl_get_dmabuf_info(struct file *filep,
args->flags = flags;
/* Copy metadata buffer to user mode */
if (metadata_buffer) {
if (metadata_buffer && args->metadata_ptr) {
r = copy_to_user((void __user *)args->metadata_ptr,
metadata_buffer, args->metadata_size);
if (r != 0)