AMDGPU_GEM_OP_GET_MAPPING_INFO looks up the GEM object from the file handle and then locks the object and VM before resolving the BO-VA. The GEM object reference keeps the BO alive, but it does not keep the per-file handle open.
If a racing close drops the last handle reference in that window, amdgpu_gem_object_close() can remove the BO-VA before amdgpu_vm_bo_find() runs. The ioctl then walks the BO-VA mapping lists unconditionally. Return -EINVAL if the BO is no longer associated with this VM. Suggested-by: Christian König <[email protected]> Signed-off-by: Yousef Alhouseen <[email protected]> --- Changes in v2: - Describe the handle-close race instead of an initially unmapped BO. - Return -EINVAL instead of -ENOENT. drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c index 212c14d99..6f5b6f4c2 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c @@ -1087,6 +1087,12 @@ int amdgpu_gem_op_ioctl(struct drm_device *dev, void *data, struct drm_amdgpu_gem_vm_entry *vm_entries; struct amdgpu_bo_va_mapping *mapping; int num_mappings = 0; + + if (!bo_va) { + r = -EINVAL; + goto out_exec; + } + /* * num_entries is set as an input to the size of the user-allocated array of * drm_amdgpu_gem_vm_entry stored at args->value. -- 2.54.0
