On Mon, May 10, 2021 at 3:30 PM kernel test robot <lkp@xxxxxxxxx> wrote: > All warnings (new ones prefixed by >>): > > In file included from include/linux/kernel.h:10, > from include/linux/list.h:9, > from include/linux/module.h:12, > from drivers/net/arcnet/com20020.c:31: > drivers/net/arcnet/com20020.c: In function 'com20020_reset': > >> include/linux/compiler.h:70:32: warning: 'inbyte' is used uninitialized in this function [-Wuninitialized] > 70 | (__if_trace.miss_hit[1]++,1) : \ > | ^ > drivers/net/arcnet/com20020.c:286:9: note: 'inbyte' was declared here > 286 | u_char inbyte; > | ^~~~~~ This looks like a real problem with the patch: the insb()/insw()/insl() helpers should memset(buffer, 0xff, size) to avoid using random stack data. Arnd