Arch Linux Security Advisory ASA-201703-7

Severity: Low
Date : 2017-03-13
CVE-ID : CVE-2017-2636
Package : linux-grsec
Type : privilege escalation
Remote : No
Link : https://security.archlinux.org/AVG-201

Summary

The package linux-grsec before version 1:4.9.14.r201703121245-1 is
vulnerable to privilege escalation.

Resolution

Upgrade to 1:4.9.14.r201703121245-1.

pacman -Syu “linux-grsec>=1:4.9.14.r201703121245-1”

The problem has been fixed upstream in version 4.9.14.r201703121245.

Workaround

echo “install n_hdlc /bin/true” >> /etc/modprobe.d/disable-

n_hdlc.conf

Description

A race condition flaw was found in the N_HLDC Linux kernel driver when
accessing the n_hdlc.tbuf list that can lead to double free. A local,
unprivileged user able to set the HDLC line discipline on the tty
device could use this flaw to crash the system or increase their
privileges on the system.

Impact

A local attacker is able to escalate privileges or crash the system if
the n_hdlc kernel module has already been explicitly loaded by an
administrator.

References

https://bugs.archlinux.org/task/53242
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=82f2341c94d270421f383641b7cd670e474db56b
http://seclists.org/oss-sec/2017/q1/569
https://security.archlinux.org/CVE-2017-2636