Advisories ยป MGASA-2018-0106

Updated kernel packages fix security vulnerabilities

Publication date: 05 Feb 2018
Type: security
Affected Mageia releases : 6
CVE: CVE-2017-5715 , CVE-2017-5753 , CVE-2017-8824 , CVE-2017-1000410


This kernel update is based on the upstream 4.14.16 and and fixes
several security issues.

The most important fixes in this update is for the security issue named
"Spectre, variant 2 (CVE-2017-5715)" that is partly mitigated by enabling
retpoline support. For full retpoline mitigation, kernel needs to be built
with a retpoline-aware cpmpiler (something we just added in testing), so
next kernel will be built with full retpoline mititgation.
For the security issue known as "Spectre, variant 1" there are some
lfence bits added but full fix also needs microcode support, and that is
something we dont have control over.

The BPF interpreter has been used as part of the spectre 2 attack
CVE-2017-5715. To make attacker job harder introduce BPF_JIT_ALWAYS_ON
config option that removes interpreter from the kernel in favor of JIT-only
mode. This is now enabled by default in Mageia kernels.

KVM on x86 gained a memory barrier on vmcs field lookup as part of
mitigating Spectre variant 2 (CVE-2017-5753).

Other security fixes in this update:

Linux kernel version 3.3-rc1 and later is affected by a vulnerability lies
in the processing of incoming L2CAP commands - ConfigRequest, and
ConfigResponse messages. This info leak is a result of uninitialized stack
variables that may be returned to an attacker in their uninitialized state.
By manipulating the code flows that precede the handling of these
configuration messages, an attacker can also gain some control over which
data will be held in the uninitialized stack variables. This can allow him
to bypass KASLR, and stack canaries protection - as both pointers and stack
canaries may be leaked in this manner (CVE-2017-1000410).

The dccp_disconnect function in net/dccp/proto.c in the Linux kernel through
4.14.3 allows local users to gain privileges or cause a denial of service
(use-after-free) via an AF_UNSPEC connect system call during the DCCP_LISTEN
state (CVE-2017-8824).

WireGuard has been updated to 0.0.20180118.

For other fixes, see the referenced changelogs.