From: Ben Hutchings <ben.hutchings@codethink.co.uk>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Sasha Levin <Alexander.Levin@microsoft.com>
Cc: stable <stable@vger.kernel.org>
Subject: [stable] timer/debug: Change /proc/timer_list from 0444 to 0400
Date: Mon, 17 Dec 2018 22:01:03 +0000 [thread overview]
Message-ID: <1545084063.19315.130.camel@codethink.co.uk> (raw)
Please pick this commit for 4.14 and older stable branches:
commit 8e7df2b5b7f245c9bd11064712db5cb69044a362
Author: Ingo Molnar <mingo@kernel.org>
Date: Mon Nov 13 07:15:41 2017 +0100
timer/debug: Change /proc/timer_list from 0444 to 0400
In older kernel versions this file makes it far too easy to exploit
arbitrary-write bugs. It's possible to hide the pointers from
unprivileged users by setting the kernel.kptr_restrict sysctl, but that
wasn't done by default.
(Upstream commits c1eba5bcb643 "timer: Pass timer_list pointer to
callbacks unconditionally" and ad67b74d2469 "printk: hash addresses
printed with %p" provide more general mitigations, but don't seem to be
suitable for stable.)
Ben.
--
Ben Hutchings, Software Developer Codethink Ltd
https://www.codethink.co.uk/ Dale House, 35 Dale Street
Manchester, M1 2HF, United Kingdom
next reply other threads:[~2018-12-17 22:01 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-17 22:01 Ben Hutchings [this message]
2018-12-17 23:32 ` [stable] timer/debug: Change /proc/timer_list from 0444 to 0400 Sasha Levin
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