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From: Matthew Wilcox <willy@infradead.org>
To: Kees Cook <keescook@chromium.org>
Cc: linux-mm@kvack.org, Thomas Gleixner <tglx@linutronix.de>,
	linux-hardening@vger.kernel.org
Subject: Re: [PATCH v3 3/3] mm/usercopy: Detect compound page overruns
Date: Mon, 13 Dec 2021 23:44:33 +0000	[thread overview]
Message-ID: <Ybfa4RV4fRkgjh8D@casper.infradead.org> (raw)
In-Reply-To: <202112131249.0D2A4A2C7@keescook>

On Mon, Dec 13, 2021 at 12:52:22PM -0800, Kees Cook wrote:
> On Mon, Dec 13, 2021 at 02:27:03PM +0000, Matthew Wilcox (Oracle) wrote:
> > Move the compound page overrun detection out of
> > CONFIG_HARDENED_USERCOPY_PAGESPAN so it's enabled for more people.
> 
> I'd argue that everything else enabled by USERCOPY_PAGESPAN could be
> removed now too. Do you want to add a 4th patch to rip that out?
> 
> https://github.com/KSPP/linux/issues/163

I don't mind ... is it your assessment that it's not worth checking for
a copy_to/from_user that spans a boundary between a reserved and
!reserved page, or overlaps the boundary of rodata/bss/data/CMA?

I have no basis on which to judge that, so it's really up to you.


  reply	other threads:[~2021-12-13 23:44 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-13 14:27 [PATCH v3 0/3] Assorted improvements to usercopy Matthew Wilcox (Oracle)
2021-12-13 14:27 ` [PATCH v3 1/3] mm/usercopy: Check kmap addresses properly Matthew Wilcox (Oracle)
2021-12-13 14:27 ` [PATCH v3 2/3] mm/usercopy: Detect vmalloc overruns Matthew Wilcox (Oracle)
2021-12-13 14:27 ` [PATCH v3 3/3] mm/usercopy: Detect compound page overruns Matthew Wilcox (Oracle)
2021-12-13 20:52   ` Kees Cook
2021-12-13 23:44     ` Matthew Wilcox [this message]
2021-12-13 23:50       ` Kees Cook
2021-12-13 19:18 ` [PATCH v3 0/3] Assorted improvements to usercopy William Kucharski
2021-12-13 20:27   ` Matthew Wilcox
2021-12-13 20:47     ` Kees Cook
2021-12-13 20:53       ` William Kucharski
2021-12-13 21:16       ` Matthew Wilcox
2021-12-13 23:47         ` Kees Cook

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