From: Kees Cook <keescook@chromium.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Arnaldo Carvalho de Melo <acme@ghostprotocols.net>,
Cong Ding <dinggnu@gmail.com>,
"H. Peter Anvin" <hpa@linux.intel.com>,
Ingo Molnar <mingo@elte.hu>, Ingo Molnar <mingo@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Mathias Krause <minipli@googlemail.com>,
Michael Davidson <md@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Subject: Re: [GIT PULL] x86/kaslr for v3.14
Date: Tue, 21 Jan 2014 10:37:00 -0800 [thread overview]
Message-ID: <CAGXu5jLdz2b2gozgK_TWjUzGacwyD_qb47Yc8rkmWkzVe1zcWg@mail.gmail.com> (raw)
In-Reply-To: <52DE8231.6080408@zytor.com>
On Tue, Jan 21, 2014 at 6:20 AM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 01/21/2014 01:00 AM, Peter Zijlstra wrote:
>>>
>>> So this is presumably something that needs to be fixed in perf?
>>
>> Where do we learn about the offset from userspace?
>
> Now this is tricky... if this offset is too easy to get it completely
> defeats kASLR. On the other hand, I presume that if we are exporting
> /proc/kcore we're not secure anyway. Kees, I assume that in "secure"
> mode perf annotations simply wouldn't work anyway?
The goal scope of the kernel base address randomization is to keep it
secret from non-root users, confined processes, and/or remote systems.
For local secrecy, if you're running with kaslr and you haven't set
kptr_restrict, dmesg_restrict, and perf_event_paranoid, that's a
problem since you're likely leaking things trivially through
/proc/kallsyms, dmesg, and/or perf.
-Kees
--
Kees Cook
Chrome OS Security
next prev parent reply other threads:[~2014-01-21 18:37 UTC|newest]
Thread overview: 70+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-20 16:47 [GIT PULL] x86/kaslr for v3.14 H. Peter Anvin
2014-01-20 22:54 ` Linus Torvalds
2014-01-20 23:00 ` H. Peter Anvin
2014-01-20 23:12 ` Linus Torvalds
2014-01-20 23:13 ` H. Peter Anvin
2014-01-21 9:00 ` Peter Zijlstra
2014-01-21 14:20 ` H. Peter Anvin
2014-01-21 14:39 ` Ingo Molnar
2014-01-21 14:51 ` H. Peter Anvin
2014-01-21 14:56 ` Ingo Molnar
2014-01-21 18:37 ` Kees Cook [this message]
2014-01-21 10:27 ` Ingo Molnar
2014-01-21 13:55 ` H. Peter Anvin
2014-01-21 14:03 ` Ingo Molnar
2014-01-21 14:05 ` H. Peter Anvin
2014-01-21 14:14 ` Ingo Molnar
2014-01-21 14:17 ` H. Peter Anvin
2014-01-21 5:18 ` Kees Cook
2014-01-23 9:39 ` Pavel Machek
2014-01-26 10:16 ` Richard Weinberger
2014-01-27 5:33 ` H. Peter Anvin
2014-01-27 6:49 ` Richard Weinberger
2014-01-27 6:51 ` H. Peter Anvin
2014-01-27 7:38 ` Ingo Molnar
2014-01-27 7:43 ` Ingo Molnar
2014-01-27 7:59 ` Richard Weinberger
2014-01-30 22:07 ` Vivek Goyal
2014-01-31 16:57 ` Kees Cook
2014-02-07 14:49 ` Vivek Goyal
2014-02-07 16:04 ` H. Peter Anvin
2014-02-07 16:24 ` Vivek Goyal
2014-02-07 23:16 ` Dave Young
2014-02-07 23:20 ` H. Peter Anvin
2014-02-07 23:28 ` Dave Young
2014-02-07 19:07 ` H. Peter Anvin
2014-02-07 19:44 ` Kees Cook
2014-01-27 6:52 ` H. Peter Anvin
2014-01-27 7:34 ` Richard Weinberger
2014-01-27 17:05 ` Kees Cook
2014-01-27 17:20 ` Richard Weinberger
2014-01-27 17:24 ` Kees Cook
2014-01-28 6:28 ` Ingo Molnar
2014-01-28 8:25 ` Richard Weinberger
2014-01-28 15:55 ` H. Peter Anvin
2014-01-28 16:25 ` Richard Weinberger
2014-01-28 16:30 ` H. Peter Anvin
2014-01-28 16:51 ` Linus Torvalds
2014-01-28 17:05 ` Ingo Molnar
2014-01-28 17:12 ` Linus Torvalds
2014-01-28 17:24 ` Richard Weinberger
2014-01-28 17:35 ` Linus Torvalds
2014-01-28 17:52 ` Richard Weinberger
2014-01-28 17:56 ` Linus Torvalds
2014-01-28 18:54 ` Richard Weinberger
2014-01-28 19:48 ` Ingo Molnar
2014-01-28 20:07 ` Linus Torvalds
2014-01-28 20:15 ` Borislav Petkov
2014-01-28 20:25 ` Linus Torvalds
2014-01-28 20:28 ` Richard Weinberger
2014-01-28 20:38 ` H. Peter Anvin
2014-01-29 8:25 ` Ingo Molnar
2014-01-29 10:40 ` Borislav Petkov
2014-01-28 20:49 ` Borislav Petkov
2014-01-28 23:37 ` Borislav Petkov
2014-01-28 21:08 ` Dave Jones
2014-01-29 6:36 ` Mike Galbraith
2014-01-29 8:11 ` Ingo Molnar
2014-01-29 8:27 ` Mathias Krause
2014-01-30 9:23 ` Ingo Molnar
2014-01-30 18:15 ` Linus Torvalds
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