Ubuntu Security Notice 5579-1 - Roger Pau Monné discovered that the Xen virtual block driver in the Linux kernel did not properly initialize memory pages to be used for shared communication with the backend. A local attacker could use this to expose sensitive information. Roger Pau Monné discovered that the Xen paravirtualization frontend in the Linux kernel did not properly initialize memory pages to be used for shared communication with the backend. A local attacker could use this to expose sensitive information.
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Ubuntu Security Notice USN-5579-1
August 24, 2022
linux, linux-kvm, linux-lts-xenial vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 16.04 ESM
- Ubuntu 14.04 ESM
Summary:
Several security issues were fixed in the Linux kernel.
Software Description:
- linux: Linux kernel
- linux-kvm: Linux kernel for cloud environments
- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty
Details:
Roger Pau Monné discovered that the Xen virtual block driver in the
Linux kernel did not properly initialize memory pages to be used for
shared communication with the backend. A local attacker could use this
to expose sensitive information (guest kernel memory). (CVE-2022-26365)
Roger Pau Monné discovered that the Xen paravirtualization frontend in
the Linux kernel did not properly initialize memory pages to be used for
shared communication with the backend. A local attacker could use this
to expose sensitive information (guest kernel memory). (CVE-2022-33740)
It was discovered that the Xen paravirtualization frontend in the Linux
kernel incorrectly shared unrelated data when communicating with certain
backends. A local attacker could use this to cause a denial of service
(guest crash) or expose sensitive information (guest kernel memory).
(CVE-2022-33741)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 16.04 ESM:
linux-image-4.4.0-1113-kvm 4.4.0-1113.123
linux-image-4.4.0-233-generic 4.4.0-233.267
linux-image-4.4.0-233-lowlatency 4.4.0-233.267
linux-image-generic 4.4.0.233.239
linux-image-kvm 4.4.0.1113.110
linux-image-lowlatency 4.4.0.233.239
linux-image-virtual 4.4.0.233.239
Ubuntu 14.04 ESM:
linux-image-4.4.0-233-generic 4.4.0-233.267~14.04.1
linux-image-4.4.0-233-lowlatency 4.4.0-233.267~14.04.1
linux-image-generic-lts-xenial 4.4.0.233.202
linux-image-lowlatency-lts-xenial 4.4.0.233.202
linux-image-virtual-lts-xenial 4.4.0.233.202
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://ubuntu.com/security/notices/USN-5579-1
CVE-2022-26365, CVE-2022-33740, CVE-2022-33741