Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 50/66] drm/radeon: forbid mapping of userptr bo through radeon device file | Date | Tue, 26 Apr 2016 13:24:41 -0700 |
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3.19.8-ckt20 -stable review patch. If anyone has any objections, please let me know.
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From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= <jglisse@redhat.com>
commit b5dcec693f87cb8475f2291c0075b2422addd3d6 upstream.
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.
Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- 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 f5c0590..50ce26a 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); } -- 2.7.4
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