linux-kernel - Re: [PATCH RFT v9 4/8] fork: Add shadow stack support to clone3()

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <158190d9-a4a6-4647-84e8-f4ae036d984b@sirena.org.uk>
Date: Wed, 21 Aug 2024 18:23:18 +0100
From: Mark Brown <broonie@...nel.org>
To: "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>,
	"brauner@...nel.org" <brauner@...nel.org>
Cc: "dietmar.eggemann@....com" <dietmar.eggemann@....com>,
	"linux-kselftest@...r.kernel.org" <linux-kselftest@...r.kernel.org>,
	"shuah@...nel.org" <shuah@...nel.org>,
	"Szabolcs.Nagy@....com" <Szabolcs.Nagy@....com>,
	"dave.hansen@...ux.intel.com" <dave.hansen@...ux.intel.com>,
	"debug@...osinc.com" <debug@...osinc.com>,
	"mgorman@...e.de" <mgorman@...e.de>,
	"vincent.guittot@...aro.org" <vincent.guittot@...aro.org>,
	"fweimer@...hat.com" <fweimer@...hat.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"mingo@...hat.com" <mingo@...hat.com>,
	"rostedt@...dmis.org" <rostedt@...dmis.org>,
	"hjl.tools@...il.com" <hjl.tools@...il.com>,
	"tglx@...utronix.de" <tglx@...utronix.de>,
	"linux-api@...r.kernel.org" <linux-api@...r.kernel.org>,
	"vschneid@...hat.com" <vschneid@...hat.com>,
	"kees@...nel.org" <kees@...nel.org>,
	"will@...nel.org" <will@...nel.org>,
	"hpa@...or.com" <hpa@...or.com>,
	"jannh@...gle.com" <jannh@...gle.com>,
	"peterz@...radead.org" <peterz@...radead.org>,
	"yury.khrustalev@....com" <yury.khrustalev@....com>,
	"bp@...en8.de" <bp@...en8.de>,
	"wilco.dijkstra@....com" <wilco.dijkstra@....com>,
	"catalin.marinas@....com" <catalin.marinas@....com>,
	"bsegall@...gle.com" <bsegall@...gle.com>,
	"juri.lelli@...hat.com" <juri.lelli@...hat.com>,
	"x86@...nel.org" <x86@...nel.org>
Subject: Re: [PATCH RFT v9 4/8] fork: Add shadow stack support to clone3()

On Wed, Aug 21, 2024 at 03:54:49PM +0000, Edgecombe, Rick P wrote:
> On Wed, 2024-08-21 at 13:45 +0100, Mark Brown wrote:

> > It's entirely possible it just leaked.  My own attempts to dig through
> > the archives haven't turned up anything on the subjecti either, it seems
> > to have been there from the get go and just gone in without comment.
> > Equally it could just be that people felt that this was a more tasteful
> > way of specifying stacks, or that some future use was envisioned.

> Ok, well I'm suspicious, but won't object over it. The rest seems settled from
> my side. I may try to attract some other x86 attention to that CMPXCHG helper,
> but otherwise.

OK, I'll post what I've got (with the current ABI) today, incorporating
your x86 fixes and the tighter validation and we can see what people
think.  Perhaps Christian remembers what's going on there?

> > > Sorry for that. I looked through all the old threads expecting to find
> > > discussion, but couldn't find an answer. Is clone3 support a dependency for
> > > arm
> > > shadow stacks?

> > Catalin didn't want to merge the arm64 support without clone3(), and
> > there's code dependencies as a result.  I could unpick it and reverse
> > the ordering so long as the arm64 maintainers are OK with that since the
> > overlap is in the implementation of copy_thread() and some of the
> > dependency patches.

Actually in an off-list discussion today Catalin indicated that he's
fine with relaxing that a little so I'm in the process of picking the
dependency apart.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)