From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Alan Cox <alan@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-arch@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
kernel-hardening@lists.openwall.com,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
the arch/x86 maintainers <x86@kernel.org>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>
Subject: [kernel-hardening] Re: [PATCH v3 8/9] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths
Date: Wed, 17 Jan 2018 20:05:32 +0000 [thread overview]
Message-ID: <20180117200532.GX13338@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAPcyv4iYVcCZxdd5wHDf2av8F=E1F7UGTX9uVzX68KkrJ1ZuQQ@mail.gmail.com>
On Wed, Jan 17, 2018 at 11:54:12AM -0800, Dan Williams wrote:
> On Wed, Jan 17, 2018 at 10:52 AM, Al Viro <viro@zeniv.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.
Huh? What the hell does it do to speculative execution of "memcpy those
suckers" branch?
WARNING: multiple messages have this Message-ID (diff)
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Alan Cox <alan@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-arch@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
kernel-hardening@lists.openwall.com,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
the arch/x86 maintainers <x86@kernel.org>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v3 8/9] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths
Date: Wed, 17 Jan 2018 20:05:32 +0000 [thread overview]
Message-ID: <20180117200532.GX13338@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAPcyv4iYVcCZxdd5wHDf2av8F=E1F7UGTX9uVzX68KkrJ1ZuQQ@mail.gmail.com>
On Wed, Jan 17, 2018 at 11:54:12AM -0800, Dan Williams wrote:
> On Wed, Jan 17, 2018 at 10:52 AM, Al Viro <viro@zeniv.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.
Huh? What the hell does it do to speculative execution of "memcpy those
suckers" branch?
next prev parent reply other threads:[~2018-01-17 20:05 UTC|newest]
Thread overview: 102+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-13 18:17 [kernel-hardening] [PATCH v3 0/9] core, x86: prevent bounds-check bypass via speculative execution Dan Williams
2018-01-13 18:17 ` Dan Williams
2018-01-13 18:17 ` [kernel-hardening] [PATCH v3 1/9] Documentation: document array_ptr Dan Williams
2018-01-13 18:17 ` Dan Williams
2018-01-13 18:17 ` [kernel-hardening] [PATCH v3 2/9] arm64: implement ifence_array_ptr() Dan Williams
2018-01-13 18:17 ` Dan Williams
2018-01-13 18:17 ` [kernel-hardening] [PATCH v3 3/9] arm: " Dan Williams
2018-01-13 18:17 ` Dan Williams
2018-01-13 18:17 ` [kernel-hardening] [PATCH v3 4/9] x86: implement ifence() Dan Williams
2018-01-13 18:17 ` Dan Williams
2018-01-13 18:17 ` [kernel-hardening] [PATCH v3 5/9] x86: implement ifence_array_ptr() and array_ptr_mask() Dan Williams
2018-01-13 18:17 ` Dan Williams
2018-01-13 18:17 ` [kernel-hardening] [PATCH v3 6/9] asm/nospec: mask speculative execution flows Dan Williams
2018-01-13 18:17 ` Dan Williams
2018-01-13 18:18 ` [kernel-hardening] [PATCH v3 7/9] x86: introduce __uaccess_begin_nospec and ASM_IFENCE Dan Williams
2018-01-13 18:18 ` Dan Williams
2018-01-13 18:18 ` [kernel-hardening] [PATCH v3 8/9] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths Dan Williams
2018-01-13 18:18 ` Dan Williams
2018-01-13 19:05 ` [kernel-hardening] " Linus Torvalds
2018-01-13 19:05 ` Linus Torvalds
2018-01-13 19:33 ` [kernel-hardening] " Linus Torvalds
2018-01-13 19:33 ` Linus Torvalds
2018-01-13 20:22 ` [kernel-hardening] " Eric W. Biederman
2018-01-13 20:22 ` Eric W. Biederman
2018-01-13 20:22 ` Eric W. Biederman
2018-01-13 20:22 ` Eric W. Biederman
2018-01-16 22:23 ` [kernel-hardening] " Dan Williams
2018-01-16 22:23 ` Dan Williams
2018-01-16 22:23 ` Dan Williams
2018-01-16 22:23 ` Dan Williams
[not found] ` <CA+55aFxAFG5czVmCyhYMyHmXLNJ7pcXxWzusjZvLRh_qTGHj6Q@mail.gmail.com>
2018-01-16 22:41 ` [kernel-hardening] " Linus Torvalds
2018-01-16 22:41 ` Linus Torvalds
2018-01-17 14:17 ` [kernel-hardening] " Alan Cox
2018-01-17 14:17 ` Alan Cox
2018-01-17 18:52 ` [kernel-hardening] " Al Viro
2018-01-17 18:52 ` Al Viro
2018-01-17 19:54 ` [kernel-hardening] " Dan Williams
2018-01-17 19:54 ` Dan Williams
2018-01-17 20:05 ` Al Viro [this message]
2018-01-17 20:05 ` Al Viro
2018-01-17 20:14 ` [kernel-hardening] " Dan Williams
2018-01-17 20:14 ` Dan Williams
2018-01-18 3:06 ` [kernel-hardening] [RFC][PATCH] get rid of the use of set_fs() (by way of kernel_recvmsg()) in sunrpc Al Viro
2018-01-18 3:06 ` Al Viro
2018-01-18 3:16 ` [kernel-hardening] " Linus Torvalds
2018-01-18 3:16 ` Linus Torvalds
2018-01-18 4:43 ` [kernel-hardening] " Al Viro
2018-01-18 4:43 ` Al Viro
2018-01-18 16:29 ` [kernel-hardening] " Christoph Hellwig
2018-01-18 16:29 ` Christoph Hellwig
2018-01-18 17:10 ` [kernel-hardening] " Al Viro
2018-01-18 17:10 ` Al Viro
2018-01-18 19:31 ` [kernel-hardening] " Al Viro
2018-01-18 19:31 ` Al Viro
2018-01-18 19:37 ` [PATCH 01/10] net: separate SIOCGIFCONF handling from dev_ioctl() Al Viro
2018-01-18 19:37 ` [PATCH 02/10] devinet_ioctl(): take copyin/copyout to caller Al Viro
2018-01-22 16:40 ` Christoph Hellwig
2018-01-18 19:37 ` [PATCH 03/10] ip_rt_ioctl(): take copyin " Al Viro
2018-01-22 16:43 ` Christoph Hellwig
2018-01-18 19:37 ` [PATCH 04/10] kill dev_ifsioc() Al Viro
2018-01-22 16:47 ` Christoph Hellwig
2018-01-18 19:37 ` [PATCH 05/10] kill bond_ioctl() Al Viro
2018-01-22 16:48 ` Christoph Hellwig
2018-01-18 19:37 ` [PATCH 06/10] kill dev_ifname32() Al Viro
2018-01-18 19:37 ` [PATCH 07/10] lift handling of SIOCIW... out of dev_ioctl() Al Viro
2018-01-18 19:37 ` [PATCH 08/10] ipconfig: use dev_set_mtu() Al Viro
2018-01-18 19:37 ` [PATCH 09/10] dev_ioctl(): move copyin/copyout to callers Al Viro
2018-01-18 19:37 ` [PATCH 10/10] kill kernel_sock_ioctl() Al Viro
2018-01-22 16:49 ` Christoph Hellwig
2018-01-24 20:52 ` David Miller
2018-01-25 0:01 ` Al Viro
2018-01-25 0:21 ` Al Viro
2018-01-25 4:11 ` David Miller
2018-01-22 16:40 ` [PATCH 01/10] net: separate SIOCGIFCONF handling from dev_ioctl() Christoph Hellwig
2018-01-18 20:33 ` [kernel-hardening] Re: [RFC][PATCH] get rid of the use of set_fs() (by way of kernel_recvmsg()) in sunrpc Al Viro
2018-01-18 20:33 ` Al Viro
2018-01-19 3:27 ` [kernel-hardening] " Al Viro
2018-01-19 3:27 ` Al Viro
2018-01-17 19:26 ` [kernel-hardening] Re: [PATCH v3 8/9] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths Linus Torvalds
2018-01-17 19:26 ` Linus Torvalds
2018-01-17 20:01 ` [kernel-hardening] " Eric Dumazet
2018-01-17 20:01 ` Eric Dumazet
2018-01-18 16:38 ` [kernel-hardening] " Christoph Hellwig
2018-01-18 16:38 ` Christoph Hellwig
2018-01-18 16:49 ` [kernel-hardening] " Linus Torvalds
2018-01-18 16:49 ` Linus Torvalds
2018-01-18 18:12 ` [kernel-hardening] " Al Viro
2018-01-18 18:12 ` Al Viro
2018-01-17 4:30 ` [kernel-hardening] " Dan Williams
2018-01-17 4:30 ` Dan Williams
2018-01-17 6:28 ` [kernel-hardening] " Al Viro
2018-01-17 6:28 ` Al Viro
2018-01-17 6:50 ` [kernel-hardening] " Dan Williams
2018-01-17 6:50 ` Dan Williams
2018-01-17 10:07 ` [kernel-hardening] " David Laight
2018-01-17 10:07 ` David Laight
2018-01-17 18:12 ` [kernel-hardening] " Dan Williams
2018-01-17 18:12 ` Dan Williams
2018-01-17 19:16 ` [kernel-hardening] " Linus Torvalds
2018-01-17 19:16 ` Linus Torvalds
2018-01-13 18:18 ` [kernel-hardening] [PATCH v3 9/9] vfs, fdtable: prevent bounds-check bypass via speculative execution Dan Williams
2018-01-13 18:18 ` Dan Williams
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180117200532.GX13338@ZenIV.linux.org.uk \
--to=viro@zeniv.linux.org.uk \
--cc=ak@linux.intel.com \
--cc=akpm@linux-foundation.org \
--cc=alan@linux.intel.com \
--cc=dan.j.williams@intel.com \
--cc=gregkh@linuxfoundation.org \
--cc=hpa@zytor.com \
--cc=keescook@chromium.org \
--cc=kernel-hardening@lists.openwall.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.