mmu_notifier_register() can get interrupted which will leave a NULL notifier.mm pointer. Catch that and return early. Signed-off-by: Das, Nirmoy <nirmoy.das@xxxxxxxxx> --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 6d1a71d6404c..d1af9d8721c4 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -378,6 +378,9 @@ i915_gem_userptr_release(struct drm_i915_gem_object *obj) { GEM_WARN_ON(obj->userptr.page_ref); + if (!obj->userptr.notifier.mm) + return; + mmu_interval_notifier_remove(&obj->userptr.notifier); obj->userptr.notifier.mm = NULL; } -- 2.34.1