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From: Kees Cook <keescook@chromium.org>
To: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "Stephen Röttger" <sroettger@google.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: PKU usage improvements for threads
Date: Mon, 22 Aug 2022 13:40:28 -0700	[thread overview]
Message-ID: <202208221331.71C50A6F@keescook> (raw)

Hi!

I was hoping to start a conversation about PKU usage for threads in two
places, which Stephen Röttger brought to my attention, with the hope of
being able to use these in Chrome:

1) It appears to be a bug that a thread without the correct PK can make
VMAs covered by a separate PK, out from under other threads. (e.g. mmap
a new mapping to wipe out the defined PK for it.) It seems that PK checks
should be made when modifying VMAs.

2) It would be very helpful to have a mechanism for the signal stack to
be PK aware, in the sense that the kernel would switch to a predefined
PK. i.e. having a new interface to sigaltstack() which includes a PK.

Are either of these something the PKU authors have considered? (Or are
there some details we're missing in this area?)

Thanks!

-Kees

-- 
Kees Cook

             reply	other threads:[~2022-08-22 20:40 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-08-22 20:40 Kees Cook [this message]
2022-08-22 21:11 ` PKU usage improvements for threads Dave Hansen
2022-08-23 11:08   ` Stephen Röttger
2022-08-23 18:12     ` Dave Hansen
2022-08-23 18:24       ` Andy Lutomirski
2022-08-24  8:51         ` Stephen Röttger
2022-08-24 16:28           ` Dave Hansen
2022-08-24 16:45           ` Andy Lutomirski
2022-08-25 12:30             ` Stephen Röttger
2022-08-25 14:36               ` Dave Hansen
2022-09-02 17:18                 ` Andy Lutomirski
2022-09-03  0:16         ` Fangfei Yang
2022-09-03  0:14       ` Fangfei Yang
2022-09-06  4:34         ` Andy Lutomirski
2022-09-06  5:58           ` Fangfei Yang

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