From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f71.google.com (mail-it0-f71.google.com [209.85.214.71]) by kanga.kvack.org (Postfix) with ESMTP id 4A8B66B0069 for ; Fri, 19 Aug 2016 16:07:54 -0400 (EDT) Received: by mail-it0-f71.google.com with SMTP id d65so19450561ith.0 for ; Fri, 19 Aug 2016 13:07:54 -0700 (PDT) Received: from mail-oi0-x241.google.com (mail-oi0-x241.google.com. [2607:f8b0:4003:c06::241]) by mx.google.com with ESMTPS id p203si5018261oia.190.2016.08.19.13.07.53 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 19 Aug 2016 13:07:53 -0700 (PDT) Received: by mail-oi0-x241.google.com with SMTP id b22so6961174oii.3 for ; Fri, 19 Aug 2016 13:07:53 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <20160817222921.GA25148@www.outflux.net> From: Linus Torvalds Date: Fri, 19 Aug 2016 13:07:53 -0700 Message-ID: Subject: Re: [PATCH] usercopy: Skip multi-page bounds checking on SLOB Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Kees Cook Cc: Rik van Riel , Laura Abbott , Linux Kernel Mailing List , linux-mm , kernel test robot On Fri, Aug 19, 2016 at 1:03 PM, Kees Cook wrote: > > Okay, I can live with that. I'd hoped to keep the general split > between the other checks (i.e. stack) and the allocator, but if this > is preferred, that's cool. :) If it had been anything else than SLOB, I might have cared. As it was, I didn't think it was worth worrying about SLOB together with hardening. It was also about the __check_object_size() modification just being very ugly, with a "return NULL" in the middle of the function. I looked at just splitting that function up, and having a part of it that would just go away when the slab allocator wasn't smart enough, but that would have been a bigger change that I'm not interested in taking right now. So it could be a future improvement, and maybe we could then re-instate SLOB with partial checking. Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org