From: Greg KH <gregkh@linuxfoundation.org>
To: Jann Horn <jannh@google.com>
Cc: stable@vger.kernel.org
Subject: Re: [PATCH for 4.18.y] x86/dumpstack: Don't dump kernel memory based on usermode RIP
Date: Mon, 3 Sep 2018 18:16:01 +0200 [thread overview]
Message-ID: <20180903161601.GA5823@kroah.com> (raw)
In-Reply-To: <20180903143248.98687-1-jannh@google.com>
On Mon, Sep 03, 2018 at 04:32:48PM +0200, Jann Horn wrote:
> commit 342db04ae71273322f0011384a9ed414df8bdae4 upstream.
>
> show_opcodes() is used both for dumping kernel instructions and for dumping
> user instructions. If userspace causes #PF by jumping to a kernel address,
> show_opcodes() can be reached with regs->ip controlled by the user,
> pointing to kernel code. Make sure that userspace can't trick us into
> dumping kernel memory into dmesg.
>
> Manually backported: show_opcodes() has changed a bit in the meantime.
> I have manually tested the backport.
>
> Fixes: 7cccf0725cf7 ("x86/dumpstack: Add a show_ip() function")
> Cc: stable@vger.kernel.org
> Link: https://lkml.kernel.org/r/20180828154901.112726-1-jannh@google.com
> Signed-off-by: Jann Horn <jannh@google.com>
> ---
> Since I manually backported this, I have removed all other
> sign-off/reviewed-by lines. I hope that's correct?
Yes, that's fine, but I added them back as this wasn't that different of
a backport :)
THanks for the patch, now queued up.
greg k-h
prev parent reply other threads:[~2018-09-03 20:36 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-03 14:32 [PATCH for 4.18.y] x86/dumpstack: Don't dump kernel memory based on usermode RIP Jann Horn
2018-09-03 16:16 ` Greg KH [this message]
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=20180903161601.GA5823@kroah.com \
--to=gregkh@linuxfoundation.org \
--cc=jannh@google.com \
--cc=stable@vger.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).