[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <CAHmME9poivOgtCkOs5cjQXT0qxayk7MV2QLUBYhoUrKu=VUhuA@mail.gmail.com>
Date: Fri, 26 Jan 2018 18:47:28 +0100
From: "Jason A. Donenfeld" <Jason@...c4.com>
To: Alan Cox <gnomes@...rguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, LKML <linux-kernel@...r.kernel.org>,
kernel-hardening@...ts.openwall.com
Subject: Re: Re: [PATCH v2] cpu: do not leak
vulnerabilities to unprivileged users
On Fri, Jan 26, 2018 at 5:43 PM, Alan Cox <gnomes@...rguk.ukuu.org.uk> wrote:
> a) The info is already trivially accessible via /proc/cpuinfo
No, /proc/cpuinfo shows if the CPU itself has these bugs, but doesn't
show whether or not the kernel has gone to lengths to mitigate these
bugs.
# grep -o 'bugs.*cpu_meltdown' -m1 /proc/cpuinfo
bugs : cpu_meltdown
# cat /sys/devices/system/cpu/vulnerabilities/meltdown
Mitigation: PTI
> or by measurement to an attacker
Right, so without this, an attacker has to measure. The purpose of
this patchset is to require the attacker to perform an additional
measurement. That seems worthwhile, especially if measurements are or
would ever become non-trivial to make.
> b) Some JIT and other environments need to know
Shouldn't JITs do the best they can with the environment they're in?
And for that, isn't /proc/cpuinfo enough?
Jason
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
