=========================================================================Ubuntu Security Notice USN-5630-1
September 22, 2022

linux-raspi-5.4 vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in the Linux kernel.

Software Description:
- linux-raspi-5.4: Linux kernel for Raspberry Pi systems

Details:

It was discovered that the framebuffer driver on the Linux kernel did 
not verify size limits when changing font or screen size, leading to an 
out-of-bounds write. A local attacker could use this to cause a denial 
of service (system crash) or possibly execute arbitrary code. 
(CVE-2021-33655)

Moshe Kol, Amit Klein and Yossi Gilad discovered that the IP 
implementation in the Linux kernel did not provide sufficient 
randomization when calculating port offsets. An attacker could possibly 
use this to expose sensitive information.
(CVE-2022-1012, CVE-2022-32296)

Norbert Slusarek discovered that a race condition existed in the perf
subsystem in the Linux kernel, resulting in a use-after-free 
vulnerability. A privileged local attacker could use this to cause a 
denial of service (system crash) or possibly execute arbitrary code. 
(CVE-2022-1729)

It was discovered that the device-mapper verity (dm-verity) driver in 
the Linux kernel did not properly verify targets being loaded into the 
device-mapper table. A privileged attacker could use this to cause a 
denial of service (system crash) or possibly execute arbitrary code. 
(CVE-2022-2503)

Domingo Dirutigliano and Nicola Guerrera discovered that the netfilter
subsystem in the Linux kernel did not properly handle rules that 
truncated packets below the packet header size. When such rules are in 
place, a remote attacker could possibly use this to cause a denial of 
service (system crash). (CVE-2022-36946)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 18.04 LTS:
   linux-image-5.4.0-1070-raspi    5.4.0-1070.80~18.04.1
   linux-image-raspi-hwe-18.04     5.4.0.1070.70

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-5630-1
   CVE-2021-33655, CVE-2022-1012, CVE-2022-1729, CVE-2022-2503,
   CVE-2022-32296, CVE-2022-36946

Package Information:
 
https://launchpad.net/ubuntu/+source/linux-raspi-5.4/5.4.0-1070.80~18.04.1