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Ubuntu: USN-4712-1: Linux kernel regression

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Ubuntu: USN-4712-1: Linux kernel regression

Severity
4
CVSS
(AV:L/AC:M/Au:N/C:P/I:P/A:P)
Published
01/28/2021
Created
02/02/2021
Added
01/29/2021
Modified
02/03/2021

Description

USN-4576-1 fixed a vulnerability in the overlay file system implementation in the Linux kernel. Unfortunately, that fix introduced a regression that could incorrectly deny access to overlay files in some situations. This update fixes the problem.

We apologize for the inconvenience.

Original vulnerability details:

Giuseppe Scrivano discovered that the overlay file system in the Linux kernel did not properly perform permission checks in some situations. A local attacker could possibly use this to bypass intended restrictions and gain read access to restricted files.

Solution(s)

  • ubuntu-upgrade-linux-image-5-4-0-65-generic
  • ubuntu-upgrade-linux-image-5-4-0-65-generic-lpae
  • ubuntu-upgrade-linux-image-5-4-0-65-lowlatency
  • ubuntu-upgrade-linux-image-5-8-0-41-generic
  • ubuntu-upgrade-linux-image-5-8-0-41-generic-64k
  • ubuntu-upgrade-linux-image-5-8-0-41-generic-lpae
  • ubuntu-upgrade-linux-image-5-8-0-41-lowlatency
  • ubuntu-upgrade-linux-image-generic
  • ubuntu-upgrade-linux-image-generic-64k
  • ubuntu-upgrade-linux-image-generic-64k-hwe-20-04
  • ubuntu-upgrade-linux-image-generic-hwe-18-04
  • ubuntu-upgrade-linux-image-generic-hwe-20-04
  • ubuntu-upgrade-linux-image-generic-lpae
  • ubuntu-upgrade-linux-image-generic-lpae-hwe-18-04
  • ubuntu-upgrade-linux-image-generic-lpae-hwe-20-04
  • ubuntu-upgrade-linux-image-lowlatency
  • ubuntu-upgrade-linux-image-lowlatency-hwe-18-04
  • ubuntu-upgrade-linux-image-lowlatency-hwe-20-04
  • ubuntu-upgrade-linux-image-oem
  • ubuntu-upgrade-linux-image-oem-20-04
  • ubuntu-upgrade-linux-image-oem-osp1
  • ubuntu-upgrade-linux-image-snapdragon-hwe-18-04
  • ubuntu-upgrade-linux-image-virtual
  • ubuntu-upgrade-linux-image-virtual-hwe-18-04
  • ubuntu-upgrade-linux-image-virtual-hwe-20-04

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