Ubuntu Security Notice 3507-2 - Mohamed Ghannam discovered that a use-after-free vulnerability existed in the Netlink subsystem in the Linux kernel. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. It was discovered that the Linux kernel did not properly handle copy-on- write of transparent huge pages. A local attacker could use this to cause a denial of service or possibly gain administrative privileges. Various other issues were also addressed.
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Ubuntu Security Notice USN-3507-2
December 08, 2017
linux-gcp vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 16.04 LTS
Summary:
Several security issues were fixed in the Linux kernel.
Software Description:
- linux-gcp: Linux kernel for Google Cloud Platform (GCP) systems
Details:
Mohamed Ghannam discovered that a use-after-free vulnerability existed in
the Netlink subsystem (XFRM) in the Linux kernel. A local attacker could
use this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2017-16939)
It was discovered that the Linux kernel did not properly handle copy-on-
write of transparent huge pages. A local attacker could use this to cause a
denial of service (application crashes) or possibly gain administrative
privileges. (CVE-2017-1000405)
Fan Wu, Haoran Qiu, and Shixiong Zhao discovered that the associative array
implementation in the Linux kernel sometimes did not properly handle adding
a new entry. A local attacker could use this to cause a denial of service
(system crash). (CVE-2017-12193)
Eric Biggers discovered that the key management subsystem in the Linux
kernel did not properly restrict adding a key that already exists but is
uninstantiated. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2017-15299)
It was discovered that a null pointer dereference error existed in the
PowerPC KVM implementation in the Linux kernel. A local attacker could use
this to cause a denial of service (system crash). (CVE-2017-15306)
Eric Biggers discovered a race condition in the key management subsystem of
the Linux kernel around keys in a negative state. A local attacker could
use this to cause a denial of service (system crash) or possibly execute
arbitrary code. (CVE-2017-15951)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 16.04 LTS:
linux-image-4.13.0-1002-gcp 4.13.0-1002.5
linux-image-gcp 4.13.0.1002.4
linux-image-gke 4.13.0.1002.4
After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.
References:
https://www.ubuntu.com/usn/usn-3507-2
https://www.ubuntu.com/usn/usn-3507-1
CVE-2017-1000405, CVE-2017-12193, CVE-2017-15299, CVE-2017-15306,
CVE-2017-15951, CVE-2017-16939
Package Information:
https://launchpad.net/ubuntu/+source/linux-gcp/4.13.0-1002.5