Vulnerability of Linux kernel: use after free via __blk_drain_queue

Synthesis of the vulnerability

An attacker can force the usage of a freed memory area via __blk_drain_queue() of the Linux kernel, in order to trigger a denial of service, and possibly to run code.

Impacted products: Debian, Android OS, Linux, RHEL, SIMATIC, Slackware, SUSE Linux Enterprise Desktop, SLES, Ubuntu.

Severity of this bulletin: 2/4.

Creation date: 14/08/2019.

Références of this threat: CERTFR-2019-AVI-391, CERTFR-2019-AVI-392, CERTFR-2019-AVI-418, CERTFR-2019-AVI-419, CERTFR-2019-AVI-513, CERTFR-2020-AVI-030, CERTFR-2020-AVI-095, CERTFR-2020-AVI-125, CVE-2018-20856, DLA-1885-1, DSA-4497-1, RHSA-2019:3055-01, RHSA-2019:3076-01, RHSA-2019:3089-01, RHSA-2019:3217-01, RHSA-2020:0100-01, RHSA-2020:0103-01, RHSA-2020:0543-01, RHSA-2020:0664-01, RHSA-2020:0698-01, SSA:2019-226-01, SSB-439005, SUSE-SU-2019:2263-1, SUSE-SU-2019:2299-1, USN-4094-1, USN-4116-1, USN-4118-1, VIGILANCE-VUL-30051.

Description of the vulnerability

An attacker can force the usage of a freed memory area via __blk_drain_queue() of the Linux kernel, in order to trigger a denial of service, and possibly to run code.
Full bulletin, software filtering, emails, fixes, ... (Request your free trial)

This security vulnerability impacts software or systems such as Debian, Android OS, Linux, RHEL, SIMATIC, Slackware, SUSE Linux Enterprise Desktop, SLES, Ubuntu.

Our Vigil@nce team determined that the severity of this computer weakness bulletin is medium.

The trust level is of type confirmed by the editor, with an origin of user shell.

An attacker with a expert ability can exploit this security note.

Solutions for this threat

Linux kernel: version 4.18.7.
The version 4.18.7 is fixed:
https://cdn.kernel.org/pub/linux/kernel/v4.x/

Linux kernel: version 4.9.189.
The version 4.9.189 is fixed:
https://cdn.kernel.org/pub/linux/kernel/v4.x/

Linux kernel: version 4.4.189.
The version 4.4.189 is fixed:
https://cdn.kernel.org/pub/linux/kernel/v4.x/

Linux kernel: patch for __blk_drain_queue.
A patch is indicated in information sources.

Debian 8: new linux-4.9 packages.
New packages are available:
Debian 8: linux-4.9 4.9.168-1+deb9u5~deb8u1

Debian 9/10: new linux packages.
New packages are available:
Debian 9: linux 4.9.168-1+deb9u5
Debian 10: linux 4.19.37-5+deb10u2

Google Android/Pixel: patch for January 2020.
A patch is indicated in information sources.

RHEL 6 MRG: new kernel-rt packages.
New packages are available:
RHEL 6.0-6.10: kernel-rt 3.10.0-693.62.1.rt56.659.el6rt

RHEL 7.4: new kernel packages.
New packages are available:
RHEL 7.4: kernel 3.10.0-693.62.1.el7

RHEL 7.5: new kernel packages.
New packages are available:
RHEL 7.0-7.7: kernel 3.10.0-862.48.1.el7

RHEL 7.6: new kernel packages.
New packages are available:
RHEL 7.0-7.7: kernel 3.10.0-957.46.1.el7

RHEL 7.6: new kpatch-patch packages.
New packages are available:
RHEL 7.0-7.7: kpatch-patch 3_10_0-957_35_1-1-6.el7

RHEL 7: new kernel-alt packages.
New packages are available:
RHEL 7: kernel-alt 4.14.0-115.14.1.el7a

RHEL 7: new kernel packages.
New packages are available:
RHEL 7: kernel 3.10.0-1062.4.1.el7

RHEL 7: new kernel-rt packages.
New packages are available:
RHEL 7: kernel-rt 3.10.0-1062.4.1.rt56.1027.el7

RHEL 7: new kpatch-patch packages.
New packages are available:
RHEL 7: kpatch-patch 3_10_0-1062-1-5.el7

SIMATIC S7-1500 CPU 1518: workaround for GNU/Linux Vulnerabilities.
A workaround is indicated in the information source.

Slackware 14.2: new kernel packages.
New packages are available:
Slackware 14.2: kernel 4.4.189-*-1

SUSE LE 12 SP2: new kernel packages.
New packages are available:
SUSE LE 12 SP2: kernel 4.4.121-92.120.1

SUSE LE 12 SP3: new kernel packages.
New packages are available:
SUSE LE 12 SP3: kernel 4.4.180-94.103.1

Ubuntu 16.04: new linux-image-4.4.0 packages.
New packages are available:
Ubuntu 16.04 LTS: linux-image-generic 4.4.0.161.169

Ubuntu 16/18: new linux-image-aws packages.
New packages are available:
Ubuntu 16.04 LTS: linux-image-aws 4.15.0.1047.47
Ubuntu 18.04 LTS: linux-image-aws 4.15.0.1047.46

Ubuntu: new linux-image-4.15.0 packages.
New packages are available:
Ubuntu 16.04 LTS: linux-image-generic-hwe-16.04 4.15.0.58.79
Ubuntu 18.04 LTS: linux-image-generic 4.15.0.58.60
Full bulletin, software filtering, emails, fixes, ... (Request your free trial)

Computer vulnerabilities tracking service

Vigil@nce provides a networks vulnerabilities bulletin. The technology watch team tracks security threats targeting the computer system.