On Wed 14-12-16 11:13:11, Alan Stern wrote: > On Wed, 14 Dec 2016, Michal Hocko wrote: > > > On Tue 13-12-16 08:33:34, Alan Stern wrote: > > > On Tue, 13 Dec 2016, Michal Hocko wrote: [...] > > > > Well, my point was that it is not really hard to imagine to deplete > > > > larger contiguous memory blocks (say PAGE_ALLOC_COSTLY_ORDER). Those are > > > > still causing the OOM killer and chances are that a controlled flood of > > > > these requests could completely DoS the system. > > > > > > Putting a limit on the total size of a single transfer would prevent > > > this. > > > > Dunno, putting a limit to the user visible interface sounds wrong to me. > > In practice, I think the data transfer sizes tend to be not very large. > But I could be wrong about that. That is one part the other is whether a malicious user can abuse this to DoS the kernel which is the point I am trying to make here. Depleting non-costly high orders can be quite dangerious so allowing a free ticket to them to arbitrary user in an arbitrary amount is definitely not good. -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
