On Mon, 15 Apr 2019, Andy Lutomirski wrote: > On Mon, Apr 15, 2019 at 9:17 AM Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote: > > On Mon, Apr 15, 2019 at 06:07:44PM +0200, Thomas Gleixner wrote: > > > > Looks like stack_trace.nr_entries isn't initialized? (though this code > > > > gets eventually replaced by a later patch) > > > > > > struct initializer initialized the non mentioned fields to 0, if I'm not > > > totally mistaken. > > > > Hm, it seems you are correct. And I thought I knew C. > > > > > > Who actually reads this stack trace? I couldn't find a consumer. > > > > > > It's stored directly in the memory pointed to by @addr and that's the freed > > > cache memory. If that is used later (UAF) then the stack trace can be > > > printed to see where it was freed. > > > > Right... but who reads it? > > That seems like a reasonable question. After some grepping and some > git searching, it looks like there might not be any users. I found Anymore. There was something 10y+ ago... > SLAB_STORE_USER, but that seems to be independent. > > So maybe the whole mess should just be deleted. If anyone ever > notices, they can re-add it better. No objections from my side, but the mm people might have opinions. Thanks, tglx
