VULNERABILITY

Ubuntu: (Multiple Advisories) (CVE-2025-21971): Linux kernel vulnerabilities

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Ubuntu: (Multiple Advisories) (CVE-2025-21971): Linux kernel vulnerabilities

Severity
5
CVSS
(AV:L/AC:L/Au:S/C:N/I:N/A:C)
Published
04/01/2025
Created
05/12/2025
Added
05/08/2025
Modified
05/14/2025

Description

In the Linux kernel, the following vulnerability has been resolved: net_sched: Prevent creation of classes with TC_H_ROOT The function qdisc_tree_reduce_backlog() uses TC_H_ROOT as a termination condition when traversing up the qdisc tree to update parent backlog counters. However, if a class is created with classid TC_H_ROOT, the traversal terminates prematurely at this class instead of reaching the actual root qdisc, causing parent statistics to be incorrectly maintained. In case of DRR, this could lead to a crash as reported by Mingi Cho. Prevent the creation of any Qdisc class with classid TC_H_ROOT (0xFFFFFFFF) across all qdisc types, as suggested by Jamal.

Solution(s)

  • ubuntu-upgrade-linux-image-4-15-0-1135-fips
  • ubuntu-upgrade-linux-image-4-15-0-1142-oracle
  • ubuntu-upgrade-linux-image-4-15-0-1163-kvm
  • ubuntu-upgrade-linux-image-4-15-0-1173-gcp
  • ubuntu-upgrade-linux-image-4-15-0-1180-aws
  • ubuntu-upgrade-linux-image-4-15-0-1188-azure
  • ubuntu-upgrade-linux-image-4-15-0-2081-gcp-fips
  • ubuntu-upgrade-linux-image-4-15-0-2097-azure-fips
  • ubuntu-upgrade-linux-image-4-15-0-2118-aws-fips
  • ubuntu-upgrade-linux-image-4-15-0-237-generic
  • ubuntu-upgrade-linux-image-4-15-0-237-lowlatency
  • ubuntu-upgrade-linux-image-4-4-0-1113-fips
  • ubuntu-upgrade-linux-image-4-4-0-1143-aws
  • ubuntu-upgrade-linux-image-4-4-0-1144-kvm
  • ubuntu-upgrade-linux-image-4-4-0-1181-aws
  • ubuntu-upgrade-linux-image-4-4-0-268-generic
  • ubuntu-upgrade-linux-image-4-4-0-268-lowlatency
  • ubuntu-upgrade-linux-image-aws
  • ubuntu-upgrade-linux-image-aws-fips
  • ubuntu-upgrade-linux-image-aws-hwe
  • ubuntu-upgrade-linux-image-aws-lts-18-04
  • ubuntu-upgrade-linux-image-azure
  • ubuntu-upgrade-linux-image-azure-fips
  • ubuntu-upgrade-linux-image-azure-lts-18-04
  • ubuntu-upgrade-linux-image-fips
  • ubuntu-upgrade-linux-image-gcp
  • ubuntu-upgrade-linux-image-gcp-fips
  • ubuntu-upgrade-linux-image-gcp-lts-18-04
  • ubuntu-upgrade-linux-image-generic
  • ubuntu-upgrade-linux-image-generic-hwe-16-04
  • ubuntu-upgrade-linux-image-generic-lts-xenial
  • ubuntu-upgrade-linux-image-gke
  • ubuntu-upgrade-linux-image-kvm
  • ubuntu-upgrade-linux-image-lowlatency
  • ubuntu-upgrade-linux-image-lowlatency-hwe-16-04
  • ubuntu-upgrade-linux-image-lowlatency-lts-xenial
  • ubuntu-upgrade-linux-image-oem
  • ubuntu-upgrade-linux-image-oracle
  • ubuntu-upgrade-linux-image-oracle-lts-18-04
  • ubuntu-upgrade-linux-image-virtual
  • ubuntu-upgrade-linux-image-virtual-hwe-16-04
  • ubuntu-upgrade-linux-image-virtual-lts-xenial

References

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