Arch Linux alert ASA-201710-26 (kernel)

From:
    	     
 
Santiago Torres-Arias <santiago@archlinux.org> 
To:
    	     
 
Archlinux security <arch-security@archlinux.org> 
Subject:
    	     
 
[arch-security] [ASA-201710-26] linux: privilege escalation 
Date:
    	     
 
Tue, 17 Oct 2017 16:23:03 -0400
Message-ID:
    	     
 
<20171017202303.yacsmwf5pbwcvsck@riseup.net>
Arch Linux Security Advisory ASA-201710-26
==========================================

Severity: High
Date    : 2017-10-17
CVE-ID  : CVE-2017-5123
Package : linux
Type    : privilege escalation
Remote  : No
Link    : https://security.archlinux.org/AVG-444

Summary
=======

The package linux before version 4.13.7-1 is vulnerable to privilege
escalation.

Resolution
==========

Upgrade to 4.13.7-1.

# pacman -Syu "linux>=4.13.7-1"

The problem has been fixed upstream in version 4.13.7.

Workaround
==========

None.

Description
===========

It was discovered that when the waitid() syscall in Linux kernel v4.13
was refactored, it accidentally stopped checking that the incoming
argument was pointing to userspace. This allowed local attackers to
write directly to kernel memory, which could lead to privilege
escalation.

Impact
======

A local attacker is able to escalate privileges on the affected host.

References
==========

http://www.openwall.com/lists/oss-security/2017/10/12/18
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/...
https://security.archlinux.org/CVE-2017-5123