From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 30DC69000BD for ; Sun, 18 Sep 2011 13:05:50 -0400 (EDT) Received: by bkbzs2 with SMTP id zs2so6088556bkb.14 for ; Sun, 18 Sep 2011 10:05:47 -0700 (PDT) Date: Sun, 18 Sep 2011 21:05:12 +0400 From: Vasiliy Kulikov Subject: Re: [kernel-hardening] Re: [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo Message-ID: <20110918170512.GA2351@albatros> References: <20110910164001.GA2342@albatros> <20110910164134.GA2442@albatros> <20110914192744.GC4529@outflux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110914192744.GC4529@outflux.net> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: kernel-hardening@lists.openwall.com, Kees Cook , Cyrill Gorcunov , Al Viro , Christoph Lameter , Pekka Enberg , Matt Mackall , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dan Rosenberg , Theodore Tso , Alan Cox , Jesper Juhl , Linus Torvalds Hi Andrew, On Wed, Sep 14, 2011 at 12:27 -0700, Kees Cook wrote: > On Sat, Sep 10, 2011 at 08:41:34PM +0400, Vasiliy Kulikov wrote: > > Historically /proc/slabinfo has 0444 permissions and is accessible to > > the world. slabinfo contains rather private information related both to > > the kernel and userspace tasks. Depending on the situation, it might > > reveal either private information per se or information useful to make > > another targeted attack. Some examples of what can be learned by > > reading/watching for /proc/slabinfo entries: > > ... > > World readable slabinfo simplifies kernel developers' job of debugging > > kernel bugs (e.g. memleaks), but I believe it does more harm than > > benefits. For most users 0444 slabinfo is an unreasonable attack vector. > > > > Signed-off-by: Vasiliy Kulikov > > Haven't had any mass complaints about the 0400 in Ubuntu (sorry Dave!), so > I'm obviously for it. > > Reviewed-by: Kees Cook Looks like the members of the previous slabinfo discussion don't object against the patch now and it got two other Reviewed-by responses. Can you merge it as-is or should I probably convince someone else? Thanks, -- Vasiliy Kulikov http://www.openwall.com - bringing security into open computing environments -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org