USN-3523-1: Linux kernel vulnerabilities
Ubuntu Security Notice USN-3523-1
9th January, 2018
linux vulnerabilities
A security issue affects these releases of Ubuntu and its
derivatives:
- Ubuntu 17.10
Summary
Several security issues were fixed in the Linux kernel.
Software description
- linux
– Linux kernel
Details
Jann Horn discovered that microprocessors utilizing speculative execution
and indirect branch prediction may allow unauthorized memory reads via
sidechannel attacks. This flaw is known as Meltdown. A local attacker could
use this to expose sensitive information, including kernel memory.
(CVE-2017-5754)
Jann Horn discovered that the Berkeley Packet Filter (BPF) implementation
in the Linux kernel did not properly check the relationship between pointer
values and the BPF stack. A local attacker could use this to cause a denial
of service (system crash) or possibly execute arbitrary code.
(CVE-2017-17863)
Jann Horn discovered that the Berkeley Packet Filter (BPF) implementation
in the Linux kernel improperly performed sign extension in some situations.
A local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code. (CVE-2017-16995)
Alexei Starovoitov discovered that the Berkeley Packet Filter (BPF)
implementation in the Linux kernel contained a branch-pruning logic issue
around unreachable code. A local attacker could use this to cause a denial
of service. (CVE-2017-17862)
Jann Horn discovered that the Berkeley Packet Filter (BPF) implementation
in the Linux kernel mishandled pointer data values in some situations. A
local attacker could use this to to expose sensitive information (kernel
memory). (CVE-2017-17864)
Update instructions
The problem can be corrected by updating your system to the following
package version:
- Ubuntu 17.10:
-
linux-image-4.13.0-25-lowlatency
4.13.0-25.29
-
linux-image-generic
4.13.0.25.26
-
linux-image-4.13.0-25-generic
4.13.0-25.29
-
linux-image-lowlatency
4.13.0.25.26
To update your system, please follow these instructions:
https://wiki.ubuntu.com/Security/Upgrades.
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
Source: USN-3523-1: Linux kernel vulnerabilities
