On Wed, Oct 23, 2019 at 08:05:49PM +0200, Thomas Gleixner wrote: > Prevent this by checking the validity of the cea_exception_stack base > address and bailing out if it is zero. Could also initialise cea_exception_stack to -1? That would lead to it being caught by ... > end = begin + sizeof(struct cea_exception_stacks); > /* Bail if @stack is outside the exception stack area. */ > if (stk < begin || stk >= end) this existing check.