CVE-2022-2503

Published: 12 August 2022

Dm-verity is used for extending root-of-trust to root filesystems. LoadPin builds on this property to restrict module/firmware loads to just the trusted root filesystem. Device-mapper table reloads currently allow users with root privileges to switch out the target with an equivalent dm-linear target and bypass verification till reboot. This allows root to bypass LoadPin and can be used to load untrusted and unverified kernel modules and firmware, which implies arbitrary kernel execution and persistence for peripherals that do not verify firmware updates. We recommend upgrading past commit 4caae58406f8ceb741603eee460d79bacca9b1b5

From the Ubuntu security team

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.

Priority

Medium

CVSS 3 base score: 6.7

Status

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-2503
• https://github.com/google/security-research/security/advisories/GHSA-6vq3-w69p-w63m
• https://ubuntu.com/security/notices/USN-5594-1
• https://ubuntu.com/security/notices/USN-5599-1
• https://ubuntu.com/security/notices/USN-5602-1
• https://ubuntu.com/security/notices/USN-5616-1
• https://ubuntu.com/security/notices/USN-5622-1
• https://ubuntu.com/security/notices/USN-5623-1
• https://ubuntu.com/security/notices/USN-5630-1
• NVD
• Launchpad
• Debian