CVE-2025-21919

Aliases:UBUNTU-CVE-2025-21919DEBIAN-CVE-2025-21919
Advisory lineage Upstream: 0 Downstream: 53
Modified
Published: 01 Apr 2025, 15:40
Last modified:08 Sept 2026, 08:40

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.23% LOW
0% probability +0.15%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

01 Apr 2025, 15:40
Published
Vulnerability first disclosed
08 Sept 2026, 08:40
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: sched/fair: Fix potential memory corruption in child_cfs_rq_on_list child_cfs_rq_on_list attempts to convert a 'prev' pointer to a cfs_rq. This 'prev' pointer can originate from struct rq's leaf_cfs_rq_list, making the conversion invalid and potentially leading to memory corruption. Depending on the relative positions of leaf_cfs_rq_list and the task group (tg) pointer within the struct, this can cause a memory fault or access garbage data. The issue arises in list_add_leaf_cfs_rq, where both cfs_rq->leaf_cfs_rq_list and rq->leaf_cfs_rq_list are added to the same leaf list. Also, rq->tmp_alone_branch can be set to rq->leaf_cfs_rq_list. This adds a check `if (prev == &rq->leaf_cfs_rq_list)` after the main conditional in child_cfs_rq_on_list. This ensures that the container_of operation will convert a correct cfs_rq struct. This check is sufficient because only cfs_rqs on the same CPU are added to the list, so verifying the 'prev' pointer against the current rq's list head is enough. Fixes a potential memory corruption issue that due to current struct layout might not be manifesting as a crash but could lead to unpredictable behavior when the layout changes.

CVSS Metrics

  • v4.0•MEDIUM•Score: 5.7CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.23%• Percentile: 14%

Techniques & Countermeasures

  • CWE-787•Out-of-bounds Write

    The product writes data past the end, or before the beginning, of the intended buffer.

Affected Systems

  • debian•linux

    < 6.1.133-1 | < 6.12.19-1 | < 6.12.19-1

  • debian•linux-6.1

    < 6.1.137-1~deb11u1

  • ubuntu•linux

    < 5.15.0-140.150 | < 6.8.0-84.84

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    < 5.15.0-1084.91 | < 6.8.0-1039.41

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    < 5.15.0-1084.91~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    < 6.8.0-1039.41~22.04.1

  • ubuntu•linux-aws-fips

    all | < 5.15.0-1084.91+fips1 | < 6.8.0-1039.41+fips1

  • ubuntu•linux-azure

    all | < 5.15.0-1089.98 | < 6.8.0-1038.44

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    < 5.15.0-1089.98~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    < 6.11.0-1018.18~24.04.1

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    all

  • ubuntu•linux-azure-6.8

    < 6.8.0-1036.42~22.04.1

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all | all

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-fips

    all | < 5.15.0-1089.98+fips1 | < 6.8.0-1040.46+fips1

  • ubuntu•linux-azure-nvidia

    < 6.8.0-1025.27

  • ubuntu•linux-bluefield

    all | < 5.15.0-1066.68

  • ubuntu•linux-fips

    all | < 5.15.0-140.150+fips1 | < 6.8.0-84.84+fips1

  • ubuntu•linux-gcp

    all | < 5.15.0-1083.92 | < 6.8.0-1040.42

  • ubuntu•linux-gcp-5.11

    all

  • ubuntu•linux-gcp-5.13

    all

  • ubuntu•linux-gcp-5.15

    < 5.15.0-1083.92~20.04.1

  • ubuntu•linux-gcp-5.19

    all

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gcp-6.11

    < 6.11.0-1016.16~24.04.1

  • ubuntu•linux-gcp-6.2

    all

  • ubuntu•linux-gcp-6.5

    all

  • ubuntu•linux-gcp-6.8

    < 6.8.0-1040.42~22.04.1

  • ubuntu•linux-gcp-fips

    all | < 5.15.0-1083.92+fips1 | < 6.8.0-1040.42+fips1

  • ubuntu•linux-gke

    all | < 5.15.0-1081.87 | < 6.8.0-1036.40

  • ubuntu•linux-gke-4.15

    all

  • ubuntu•linux-gke-5.15

    all

Showing first 50 affected entries in server-rendered view.

References (44)