From: Peter Zijlstra <peterz@infradead.org>
To: Andy Lutomirski <luto@amacapital.net>
Cc: David Smith <dsmith@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>, "H. Peter Anvin" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"Frank Ch. Eigler" <fche@redhat.com>
Subject: Re: [RFC][PATCH] x86: Verify access_ok() context
Date: Fri, 20 Jan 2017 09:24:06 +0100 [thread overview]
Message-ID: <20170120082406.GJ6515@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <CALCETrUTtg5GRmn-rKMUHfLSgDh8PPJn2MmKtmQTYOKV_jisQw@mail.gmail.com>
On Wed, Jan 18, 2017 at 04:19:47PM -0800, Andy Lutomirski wrote:
> ISTM even with pagefault_disable() in play, using access_ok() from,
> say, interrupt context is dangerous unless you've first checked that
> you're in a task. But I guess that in_task() would still return
> false, e.g. in perf.
The test was created exactly because perf was using access_ok()
_wrongly_. See commit: ae31fe51a3cc ("perf/x86: Restore TASK_SIZE check
on frame pointer").
next prev parent reply other threads:[~2017-01-20 8:24 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-22 9:57 [RFC][PATCH] x86: Verify access_ok() context Peter Zijlstra
2016-11-22 17:28 ` Andy Lutomirski
2016-11-22 19:37 ` Peter Zijlstra
2016-11-22 19:42 ` Linus Torvalds
2016-12-05 10:27 ` Peter Zijlstra
2017-01-16 20:27 ` David Smith
2017-01-16 21:14 ` Thomas Gleixner
2017-01-18 22:16 ` David Smith
2017-01-19 0:19 ` Andy Lutomirski
2017-01-19 15:37 ` David Smith
2017-01-20 8:24 ` Peter Zijlstra [this message]
2017-01-20 8:50 ` Thomas Gleixner
2017-01-19 18:12 ` Thomas Gleixner
2017-01-19 20:22 ` Frank Ch. Eigler
2017-01-19 20:50 ` Thomas Gleixner
2017-01-19 21:27 ` Frank Ch. Eigler
2017-01-19 22:20 ` Peter Zijlstra
2017-01-19 23:04 ` Thomas Gleixner
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