Date: Tue, 20 Feb 2018 12:21:11 +1100 From: Dave Chinner <dchinner@...hat.com> To: Kees Cook <keescook@...omium.org> Cc: Igor Stoppa <igor.stoppa@...wei.com>, Matthew Wilcox <willy@...radead.org>, Randy Dunlap <rdunlap@...radead.org>, Jonathan Corbet <corbet@....net>, Michal Hocko <mhocko@...nel.org>, Laura Abbott <labbott@...hat.com>, Jerome Glisse <jglisse@...hat.com>, Christoph Hellwig <hch@...radead.org>, Christoph Lameter <cl@...ux.com>, linux-security-module <linux-security-module@...r.kernel.org>, Linux-MM <linux-mm@...ck.org>, LKML <linux-kernel@...r.kernel.org>, Kernel Hardening <kernel-hardening@...ts.openwall.com> Subject: Re: [RFC PATCH v16 0/6] mm: security: ro protection for dynamic data On Mon, Feb 12, 2018 at 03:32:36PM -0800, Kees Cook wrote: > On Mon, Feb 12, 2018 at 8:52 AM, Igor Stoppa <igor.stoppa@...wei.com> wrote: > > This patch-set introduces the possibility of protecting memory that has > > been allocated dynamically. > > > > The memory is managed in pools: when a memory pool is turned into R/O, > > all the memory that is part of it, will become R/O. > > > > A R/O pool can be destroyed, to recover its memory, but it cannot be > > turned back into R/W mode. > > > > This is intentional. This feature is meant for data that doesn't need > > further modifications after initialization. > > This series came up in discussions with Dave Chinner (and Matthew > Wilcox, already part of the discussion, and others) at LCA. I wonder > if XFS would make a good initial user of this, as it could allocate > all the function pointers and other const information about a > superblock in pmalloc(), keeping it separate from the R/W portions? > Could other filesystems do similar things? I wasn't cc'd on this patchset, (please use david@...morbit.com for future postings) so I can't really say anything about it right now. My interest for XFS was that we have a fair amount of static data in XFS that we set up at mount time and it never gets modified after that. I'm not so worried about VFS level objects (that's a much more complex issue) but there is a lot of low hanging fruit in the XFS structures we could convert to write-once structures. Cheers, Dave. -- Dave Chinner dchinner@...hat.com
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.