On Thu, Dec 15, 2016 at 11:44:13PM +0300, Dan Carpenter wrote: > Hello Tvrtko Ursulin, > > The patch a19d6ff29a82: "drm/i915: Small compaction of the engine > init code" from Jun 23, 2016, leads to the following static checker > warning: > > drivers/gpu/drm/i915/intel_lrc.c:1973 logical_render_ring_init() > warn: passing freed memory 'engine' > > drivers/gpu/drm/i915/intel_lrc.c > 1970 > 1971 ret = logical_ring_init(engine); > 1972 if (ret) { > 1973 lrc_destroy_wa_ctx_obj(engine); > > The problem is that logical_ring_init() frees "engine" on the error > path so this is a use after free. And calls lrc_destroy_wa_ctx_obj() in the process. So we can diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 067394b0a769..1c1bad8ae7b0 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -1940,12 +1940,7 @@ int logical_render_ring_init(struct intel_engine_cs *engine) ret); } - ret = logical_ring_init(engine); - if (ret) { - lrc_destroy_wa_ctx_obj(engine); - } - - return ret; + return logical_ring_init(engine); } int logical_xcs_ring_init(struct intel_engine_cs *engine) -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel