Follow @Openwall on Twitter for new release announcements and other news
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Wed, 17 Jan 2018 11:54:12 -0800
From: Dan Williams <dan.j.williams@...el.com>
To: Al Viro <viro@...iv.linux.org.uk>
Cc: Alan Cox <alan@...ux.intel.com>, Linus Torvalds <torvalds@...ux-foundation.org>, 
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>, linux-arch@...r.kernel.org, 
	Andi Kleen <ak@...ux.intel.com>, Kees Cook <keescook@...omium.org>, 
	kernel-hardening@...ts.openwall.com, 
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>, "the arch/x86 maintainers" <x86@...nel.org>, 
	Ingo Molnar <mingo@...hat.com>, "H. Peter Anvin" <hpa@...or.com>, Thomas Gleixner <tglx@...utronix.de>, 
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH v3 8/9] x86: use __uaccess_begin_nospec and ASM_IFENCE in
 get_user paths

On Wed, Jan 17, 2018 at 10:52 AM, Al Viro <viro@...iv.linux.org.uk> wrote:
> On Wed, Jan 17, 2018 at 02:17:26PM +0000, Alan Cox wrote:
[..]
>         Incidentally, what about copy_to_iter() and friends?  They
> check iov_iter flavour and go either into the "copy to kernel buffer"
> or "copy to userland" paths.  Do we need to deal with mispredictions
> there?  We are calling a bunch of those on read()...
>

Those should be protected by the conversion of __uaccess_begin to
__uaccess_begin_nospec that includes the lfence.

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.