From: "PaX Team" <pageexec@freemail.hu>
To: Mark Rutland <mark.rutland@arm.com>
Cc: kernel-hardening@lists.openwall.com,
Kees Cook <keescook@chromium.org>,
Emese Revfy <re.emese@gmail.com>,
"AKASHI, Takahiro" <takahiro.akashi@linaro.org>,
park jinbum <jinb.park7@gmail.com>,
Daniel Micay <danielmicay@gmail.com>,
linux-kernel@vger.kernel.org, spender@grsecurity.net
Subject: [kernel-hardening] Re: [PATCH] gcc-plugins: Add structleak for more stack initialization
Date: Mon, 16 Jan 2017 20:30:29 +0100 [thread overview]
Message-ID: <587D1F55.2222.8A262A4@pageexec.freemail.hu> (raw)
In-Reply-To: <20170116152425.GG5908@leverpostej>
On 16 Jan 2017 at 15:24, Mark Rutland wrote:
> To me, it seems that the __user annotation can only be an indicator of
> an issue by chance. We have structures with __user pointers in structs
> that will never be copied to userspace, and conversely we have structs
> that don't contain a __user field, but will be copied to userspace.
>
> Maybe it happens that structs in more complex systems are more likely to
> contain some __user pointer. Was that part of the rationale?
it's as i explained in an earlier email: we wanted to pattern match a
specific bug situation and this was the easiest way (as you can see,
the plugin's code is very simple, not much effort went into it).
> I wonder if there's any analysis we can do of data passing into
> copy_to_user() and friends. I guess we can't follow the data flow across
> compilation units, but we might be able to follow it well enough if we
> added a new attribute that described whether data was to be copied to
> userspace.
there're are all kinds of data flow analyses you can do within and even
across translation units (summary info a'la size overflow hash tables or
LTO). i never went into that direction because i think the security goal
can be achieved without the performance impact of forced initialization.
next prev parent reply other threads:[~2017-01-16 19:30 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-13 22:02 [kernel-hardening] [PATCH] gcc-plugins: Add structleak for more stack initialization Kees Cook
2017-01-14 10:03 ` [kernel-hardening] " PaX Team
2017-01-16 15:24 ` Mark Rutland
2017-01-16 19:08 ` Daniel Micay
2017-01-16 19:30 ` PaX Team [this message]
2017-01-17 17:48 ` Mark Rutland
2017-01-17 18:54 ` PaX Team
2017-01-18 10:48 ` Mark Rutland
2017-01-17 17:48 ` Kees Cook
2017-01-16 11:54 ` Mark Rutland
2017-01-16 12:26 ` Mark Rutland
2017-01-16 19:22 ` PaX Team
2017-01-17 10:42 ` Dave P Martin
2017-01-17 17:09 ` PaX Team
2017-01-17 18:07 ` Dave P Martin
2017-01-17 19:25 ` PaX Team
2017-01-17 22:04 ` Dave P Martin
2017-01-17 17:56 ` Kees Cook
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