There are also checks in (amdgpu|radeon)_gem_mmap_ioctl() to prevent
this as well.
But it shouldn't hurt us to check that here as well. So both patches are
Reviewed-by: Christian König <christian.koenig at amd.com>
Regards,
Christian.
Am 19.04.2016 um 15:07 schrieb Jérôme Glisse:
> Allowing userptr bo which are basicly a list of page from some vma
> (so either anonymous page or file backed page) would lead to serious
> corruption of kernel structures and counters (because we overwrite
> the page->mapping field when mapping buffer).
>
> This will already block if the buffer was populated before anyone does
> try to mmap it because then TTM_PAGE_FLAG_SG would be set in in the
> ttm_tt flags. But that flag is check before ttm_tt_populate in the ttm
> vm fault handler.
>
> So to be safe just add a check to verify_access() callback.
>
> Signed-off-by: Jérôme Glisse <jglisse at redhat.com>
> Cc: <stable at vger.kernel.org>
> ---
> drivers/gpu/drm/radeon/radeon_ttm.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c
> b/drivers/gpu/drm/radeon/radeon_ttm.c
> index 7dddfdc..90f7394 100644
> --- a/drivers/gpu/drm/radeon/radeon_ttm.c
> +++ b/drivers/gpu/drm/radeon/radeon_ttm.c
> @@ -235,6 +235,8 @@ static int radeon_verify_access(struct ttm_buffer_object
> *bo, struct file *filp)
> {
> struct radeon_bo *rbo = container_of(bo, struct radeon_bo, tbo);
>
> + if (radeon_ttm_tt_has_userptr(bo->ttm))
> + return -EPERM;
> return drm_vma_node_verify_access(&rbo->gem_base.vma_node, filp);
> }
>
