On 2024-08-01 at 17:40:48 GMT, Krzysztof Niemiec wrote: > While the sysfs entries for engines are added in intel_engines_init() > during driver load, the corresponding function intel_engines_release() > does not correctly get rid of them. This can lead to a UAF if, after > failed initialization (for example when gt is set wedged on init), we > try to access the engines. > > Empty the engines llist in intel_engines_release(). > > Suggested-by: Chris Wilson <chris.p.wilson@xxxxxxxxxxxxxxx> > Signed-off-by: Krzysztof Niemiec <krzysztof.niemiec@xxxxxxxxx> > --- > drivers/gpu/drm/i915/gt/intel_engine_cs.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > index 3b740ca25000..4d30a86016f2 100644 > --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c > +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > @@ -693,6 +693,8 @@ void intel_engines_release(struct intel_gt *gt) > > memset(&engine->reset, 0, sizeof(engine->reset)); > } > + > + llist_del_all(>->i915->uabi_engines_llist); > } > > void intel_engine_free_request_pool(struct intel_engine_cs *engine) > -- > 2.45.2 > I noticed that the commit message isn't totally correct. Code changes are correct. The message should be replaced with: drm/i915/gt: Empty uabi engines list during intel_engines_release() While the uabi_engines_llist is populated in intel_engines_init() during driver load, the corresponding function intel_engines_release() does not correctly get rid of it. This can lead to a UAF if, after failed initialization (for example when gt is set wedged on init), we try to access the engines. Thanks Krzysztof
