From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christoph Hellwig <hch@infradead.org>
Subject: Re: [kernel-hardening] Re: [PATCH v9 1/4] syscalls: Verify address
 limit before returning to user-mode
Date: Tue, 9 May 2017 09:03:22 -0700
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To: Andy Lutomirski <luto@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>, Kernel Hardening <kernel-hardening@lists.openwall.com>, Greg KH <greg@kroah.com>, Heiko Carstens <heiko.carstens@de.ibm.com>, LKML <linux-kernel@vger.kernel.org>, David Howells <dhowells@redhat.com>, Dave Hansen <dave.hansen@intel.com>, "H . Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@kernel.org>, Pavel Tikhomirov <ptikhomirov@virtuozzo.com>, Peter Zijlstra <a.p.zijlstra@chello.nl>, linux-s390 <linux-s390@vger.kernel.org>, the arch/x86 maintainers <x86@kernel.org>, Russell King <linux@armlinux.org.uk>, Will Deacon <will.deacon@arm.com>, Christoph Hellwig <hch@infradead.org>, Christian Borntraeger <borntraeger@de.ibm.com>, =?iso-8859-1?Q?Ren=E9?= Nyffenegger <mail@renenyffenegger.ch>, Catalin Marinas <catalin.marinas@arm.com>, "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>, Rik van Riel <riel@redhat.com>, Kees Cook <keescook@c>
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On Tue, May 09, 2017 at 06:02:50AM -0700, Christoph Hellwig wrote:
> On Tue, May 09, 2017 at 06:00:01AM -0700, Andy Lutomirski wrote:
> > fs/splice.c has some, ahem, interesting uses that have been the source
> > of nasty exploits in the past.  Converting them to use iov_iter
> > properly would be really, really nice.  Christoph, I don't suppose
> > you'd like to do that?
> 
> I can take care of all the fs code including this one.

I spent the afternoon hacking up where I'd like this to head.  It's
completely untested as of now:

	http://git.infradead.org/users/hch/vfs.git/shortlog/refs/heads/setfs-elimination