From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Yu-cheng Yu <yu-cheng.yu@intel.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Tony Luck <tony.luck@intel.com>,
Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>,
Rik van Riel <riel@surriel.com>,
"Ravi V. Shankar" <ravi.v.shankar@intel.com>,
Fenghua Yu <fenghua.yu@intel.com>,
Peter Zijlstra <peterz@infradead.org>, sam <sunhaoyl@outlook.com>,
Kees Cook <keescook@chromium.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Dave Hansen <dave.hansen@intel.com>, Jann Horn <jannh@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Alexander Potapenko <glider@google.com>,
Al Viro <viro@zeniv.linux.org.uk>,
stable@vger.kernel.org
Subject: Re: [PATCH] x86/fpu/xstate: Clear uninitialized xstate areas in core dump
Date: Thu, 7 May 2020 18:56:52 +0200 [thread overview]
Message-ID: <20200507165652.s2cuaxasa2t5wkhx@linutronix.de> (raw)
In-Reply-To: <20200507164904.26927-1-yu-cheng.yu@intel.com>
On 2020-05-07 09:49:04 [-0700], Yu-cheng Yu wrote:
> In a core dump, copy_xstate_to_kernel() copies only enabled user xfeatures
> to a kernel buffer without touching areas for disabled xfeatures. However,
> those uninitialized areas may contain random data, which is then written to
> the core dump file and can be read by a non-privileged user.
>
> Fix it by clearing uninitialized areas.
Is the problem that copy_xstate_to_kernel() gets `kbuf' passed which
isn't zeroed? If so, would it work clean that upfront?
Sebastian
next prev parent reply other threads:[~2020-05-07 16:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-07 16:49 [PATCH] x86/fpu/xstate: Clear uninitialized xstate areas in core dump Yu-cheng Yu
2020-05-07 16:52 ` Dave Hansen
2020-05-07 17:12 ` Yu-cheng Yu
2020-05-07 16:56 ` Sebastian Andrzej Siewior [this message]
2020-05-07 17:11 ` Yu-cheng Yu
2020-05-07 18:22 ` Thomas Gleixner
2020-05-07 18:41 ` Yu-cheng Yu
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=20200507165652.s2cuaxasa2t5wkhx@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=adobriyan@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=bp@alien8.de \
--cc=dave.hansen@intel.com \
--cc=dave.hansen@linux.intel.com \
--cc=fenghua.yu@intel.com \
--cc=glider@google.com \
--cc=hpa@zytor.com \
--cc=jannh@google.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=ravi.v.shankar@intel.com \
--cc=riel@surriel.com \
--cc=stable@vger.kernel.org \
--cc=sunhaoyl@outlook.com \
--cc=tglx@linutronix.de \
--cc=tony.luck@intel.com \
--cc=viro@zeniv.linux.org.uk \
--cc=x86@kernel.org \
--cc=yu-cheng.yu@intel.com \
/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).