From: Matthew Auld Date: Mon, 7 Nov 2022 16:54:13 +0000 (+0000) Subject: drm/i915/ttm: fix uaf with lmem_userfault_list handling X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4f68332b2f89ab84285e5b6cb3d30e8b9894bef1;p=linux.git drm/i915/ttm: fix uaf with lmem_userfault_list handling In the fault handler, make sure we check if the BO maps lmem after we schedule the migration, since the current resource might change from lmem to smem, if the pages are in the non-cpu visible portion of lmem. This then leads to adding the object to the lmem_userfault_list even though the current resource is no longer lmem. If we then destroy the object, the list might still contain a link to the now free object, since we only remove it if the object is still in lmem. Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/7469 Fixes: ad74457a6b5a ("drm/i915/dgfx: Release mmap on rpm suspend") Signed-off-by: Matthew Auld Cc: Anshuman Gupta Cc: Rodrigo Vivi Cc: Andrzej Hajda Cc: Nirmoy Das Reviewed-by: Andrzej Hajda Link: https://patchwork.freedesktop.org/patch/msgid/20221107165414.56970-1-matthew.auld@intel.com (cherry picked from commit 625b74460ec0978979f883fbee117e1b97e6e35e) Signed-off-by: Tvrtko Ursulin --- diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index a4aa9500fa179..3d4305eea1aa2 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -1013,9 +1013,6 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) return VM_FAULT_SIGBUS; } - if (i915_ttm_cpu_maps_iomem(bo->resource)) - wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm); - if (!i915_ttm_resource_mappable(bo->resource)) { int err = -ENODEV; int i; @@ -1042,6 +1039,9 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf) } } + if (i915_ttm_cpu_maps_iomem(bo->resource)) + wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm); + if (drm_dev_enter(dev, &idx)) { ret = ttm_bo_vm_fault_reserved(vmf, vmf->vma->vm_page_prot, TTM_BO_VM_NUM_PREFAULT);