Arch Linux: ASA-201811-2 Low Severity: Linux-LTS Denial of Service

Arch Linux Security Advisory ASA-201811-2
========================================
Severity: Low
Date    : 2018-11-01
CVE-ID  : CVE-2018-18445
Package : linux-lts
Type    : denial of service
Remote  : No
Link    : https://security.archlinux.org/AVG-801

Summary
======
The package linux-lts before version 4.14.75-1 is vulnerable to denial
of service.

Resolution
=========
Upgrade to 4.14.75-1.

# pacman -Syu "linux-lts>=4.14.75-1"

The problem has been fixed upstream in version 4.14.75.

Workaround
=========
None.

Description
==========
In the Linux kernel 4.14.x before 4.14.75 and 4.18.x before 4.18.13,
faulty computation of numeric bounds in the BPF verifier permits out-
of-bounds memory accesses because adjust_scalar_min_max_vals in
kernel/bpf/verifier.c mishandles 32-bit right shifts.

Impact
=====
A local attacker is able to crash the kernel and leak information using
a specially crafted BPF program.

References
=========
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.13
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.75
https://bugs.chromium.org/p/project-zero/issues/detail?id=1686
https://seclists.org/oss-sec/2018/q4/69
https://security.archlinux.org/CVE-2018-18445