From: Borislav Petkov <bp@alien8.de>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: x86@kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Will Deacon <will@kernel.org>,
Dan Williams <dan.j.williams@intel.com>,
Andrea Arcangeli <aarcange@redhat.com>,
Waiman Long <longman@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Andy Lutomirski <luto@kernel.org>, Christoph Hellwig <hch@lst.de>,
David Laight <David.Laight@aculab.com>,
Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH v3] x86/uaccess: Use pointer masking to limit uaccess speculation
Date: Mon, 14 Sep 2020 19:56:04 +0200 [thread overview]
Message-ID: <20200914175604.GF680@zn.tnic> (raw)
In-Reply-To: <1d06ed6485b66b9f674900368b63d7ef79f666ca.1599756789.git.jpoimboe@redhat.com>
On Thu, Sep 10, 2020 at 12:22:53PM -0500, Josh Poimboeuf wrote:
> +/*
> + * Sanitize a user pointer such that it becomes NULL if it's not a valid user
> + * pointer. This prevents speculative dereferences of user-controlled pointers
> + * to kernel space when access_ok() speculatively returns true. This should be
> + * done *after* access_ok(), to avoid affecting error handling behavior.
Err, stupid question: can this macro then be folded into access_ok() so
that you don't have to touch so many places and the check can happen
automatically?
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-09-14 17:56 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-10 17:22 [PATCH v3] x86/uaccess: Use pointer masking to limit uaccess speculation Josh Poimboeuf
2020-09-10 19:25 ` Peter Zijlstra
2020-09-14 17:56 ` Borislav Petkov [this message]
2020-09-14 18:48 ` Dan Williams
2020-09-14 19:21 ` Borislav Petkov
2020-09-14 19:27 ` Josh Poimboeuf
2020-09-14 19:34 ` Andrew Cooper
2020-09-14 21:23 ` David Laight
2020-09-14 21:51 ` Josh Poimboeuf
2020-09-15 8:22 ` David Laight
2020-09-14 19:06 ` Dan Williams
2020-09-14 19:50 ` Josh Poimboeuf
2020-09-14 19:42 ` Borislav Petkov
2020-09-14 19:53 ` Josh Poimboeuf
2020-09-14 20:51 ` Thomas Gleixner
2020-09-23 3:38 ` Al Viro
2021-05-03 23:31 ` Josh Poimboeuf
2021-05-04 0:31 ` Al Viro
2021-05-04 4:12 ` Josh Poimboeuf
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=20200914175604.GF680@zn.tnic \
--to=bp@alien8.de \
--cc=David.Laight@aculab.com \
--cc=aarcange@redhat.com \
--cc=andrew.cooper3@citrix.com \
--cc=dan.j.williams@intel.com \
--cc=hch@lst.de \
--cc=jpoimboe@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=longman@redhat.com \
--cc=luto@kernel.org \
--cc=mark.rutland@arm.com \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=viro@zeniv.linux.org.uk \
--cc=will@kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox