On Fri, May 12, 2017 at 09:21:06PM +0100, Russell King - ARM Linux wrote: > On Fri, May 12, 2017 at 12:30:02PM -0700, Kees Cook wrote: > > I'm clearly not explaining things well enough. I shouldn't say > > "corruption", I should say "malicious manipulation". The methodology > > of attacks against the stack are quite different from the other kinds > > of attacks like use-after-free, heap overflow, etc. Being able to > > exhaust the kernel stack (either due to deep recursion or unbounded > > alloca()) > > I really hope we don't have alloca() use in the kernel. Do you have > evidence to support that assertion? > > IMHO alloca() (or similar) should not be present in any kernel code > because we have a limited stack - we have kmalloc() etc for that kind > of thing. No alloca(), but there are VLAs. Said that, the whole "what if they can bugger thread_info and/or task_struct and go after set_fs() state" is idiocy, of course - in that case the box is fucked, no matter what. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
