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Fencer Vulns
medium 4.7

CVE-2024-42102 json

Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again"

published 2024-07-30 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-39934

cvss
4.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

Revert "mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again"

Patch series "mm: Avoid possible overflows in dirty throttling".

Dirty throttling logic assumes dirty limits in page units fit into 32-bits. This patch series makes sure this is true (see patch 2/2 for more details).

This patch (of 2):

This reverts commit 9319b647902cbd5cc884ac08a8a6d54ce111fc78.

The commit is broken in several ways. Firstly, the removed (u64) cast from the multiplication will introduce a multiplication overflow on 32-bit archs if wb_thresh * bg_thresh >= 1<<32 (which is actually common - the default settings with 4GB of RAM will trigger this). Secondly, the div64_u64() is unnecessarily expensive on 32-bit archs. We have div64_ul() in case we want to be safe & cheap. Thirdly, if dirty thresholds are larger than 1<<32 pages, then dirty balancing is going to blow up in many other spectacular ways anyway so trying to fix one possible overflow is just moot.

Patch / fix

  • Linux Linux 4.19.318, 5.4.280, 5.10.222, 5.15.163, 6.1.98, 6.6.39, 6.8, 6.9.9, 6.10
  • linux Debian 12 6.1.98-1
  • linux Debian 14, Debian 13 6.9.9-1

debian advisories DEBIAN-CVE-2024-42102

  • linux Ubuntu 20.04 LTS 5.4.0-195.215
  • linux Ubuntu 22.04 LTS 5.15.0-121.131
  • linux Ubuntu 24.04 LTS 6.8.0-48.48
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1132.142
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1069.75
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1018.20
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1136.145
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1068.76

ubuntu advisories UBUNTU-CVE-2024-42102

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9 5.14.0-427.35.1.el9_4
  • rv RHEL 9 5.14.0-427.35.1.el9_4
  • perf RHEL 9 5.14.0-427.35.1.el9_4
  • rtla RHEL 9 5.14.0-427.35.1.el9_4
  • bpftool RHEL 9 7.3.0-427.35.1.el9_4
  • libperf RHEL 9 5.14.0-427.35.1.el9_4
  • kernel-rt RHEL 9 5.14.0-427.35.1.el9_4
  • kernel-64k RHEL 9 5.14.0-427.35.1.el9_4

red hat advisories RHSA-2024:6567RHSA-2024:6267RHSA-2024:6268

  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-24.1.21.4
  • kernel-livepatch-MICRO-6-0_Update_4 Linux Micro 6.1, Linux Micro 6.0 1-1.2
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-22.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-22.1
  • kernel-livepatch-MICRO-6-0-RT_Update_4 Linux Micro 6.1, Linux Micro 6.0 1-1.1

suse advisories SUSE-SU-2025:20164-1SUSE-SU-2025:20247-1SUSE-SU-2025:20163-1SUSE-SU-2025:20246-1SUSE-SU-2024:4387-1SUSE-SU-2024:4318-1

  • kernel AlmaLinux 9 5.14.0-427.35.1.el9_4
  • rv AlmaLinux 9 5.14.0-427.35.1.el9_4
  • perf AlmaLinux 9 5.14.0-427.35.1.el9_4
  • rtla AlmaLinux 9 5.14.0-427.35.1.el9_4
  • bpftool AlmaLinux 9 7.3.0-427.35.1.el9_4
  • libperf AlmaLinux 9 5.14.0-427.35.1.el9_4
  • kernel-rt AlmaLinux 9 5.14.0-427.35.1.el9_4
  • kernel-64k AlmaLinux 9 5.14.0-427.35.1.el9_4

almalinux advisories ALSA-2024:6567

  • kernel Rocky Linux 9 5.14.0-427.35.1.el9_4.cloud.1.0
  • kernel Rocky Linux 9 5.14.0-427.35.1.el9_4

rocky linux advisories RXSA-2024:6567RLSA-2024:6567

  • kernel CBL-Mariner 2.0 5.15.164.1-1

azure linux advisories AZL-47934

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-42102 updated cvss 4.7

kernel: Revert &#34;mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again&#34;

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: workaround, no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.82.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.82.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.82.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.82.1.el9_2
    fixed: vendor fix RHSA-2024:6267
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-427.35.1.el9_4, perf 5.14.0-427.35.1.el9_4, rtla 5.14.0-427.35.1.el9_4, kernel-devel-matched 5.14.0-427.35.1.el9_4, kernel-64k-devel-matched 5.14.0-427.35.1.el9_4, kernel-debug-devel-matched 5.14.0-427.35.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:6567
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.82.1.el9_2, rtla 5.14.0-284.82.1.el9_2, kernel-devel-matched 5.14.0-284.82.1.el9_2, kernel-64k-devel-matched 5.14.0-284.82.1.el9_2, kernel-debug-devel-matched 5.14.0-284.82.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.82.1.el9_2, +5 more
    fixed: vendor fix RHSA-2024:6267
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.3.0-427.35.1.el9_4, kernel 5.14.0-427.35.1.el9_4, kernel-64k 5.14.0-427.35.1.el9_4, kernel-core 5.14.0-427.35.1.el9_4, kernel-tools 5.14.0-427.35.1.el9_4, python3-perf 5.14.0-427.35.1.el9_4, +28 more
    fixed: vendor fix RHSA-2024:6567
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.82.1.el9_2, kernel 5.14.0-284.82.1.el9_2, kernel-64k 5.14.0-284.82.1.el9_2, kernel-core 5.14.0-284.82.1.el9_2, kernel-tools 5.14.0-284.82.1.el9_2, python3-perf 5.14.0-284.82.1.el9_2, +28 more
    fixed: vendor fix RHSA-2024:6267
  • Red Hat Enterprise Linux CRB (v. 9) libperf 5.14.0-427.35.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.35.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.35.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.35.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.35.1.el9_4 Red Hat Enterprise Linux NFV (v. 9) kernel-rt 5.14.0-427.35.1.el9_4, kernel-rt-kvm 5.14.0-427.35.1.el9_4, kernel-rt-core 5.14.0-427.35.1.el9_4, kernel-rt-modules 5.14.0-427.35.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.35.1.el9_4, kernel-rt-debug-core 5.14.0-427.35.1.el9_4, +6 more
    fixed: vendor fix RHSA-2024:6567
show 3 more
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-core 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-modules 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-debug-core 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-modules-core 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-debug-modules 5.14.0-284.82.1.rt14.367.el9_2, +4 more Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-kvm 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-core 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-modules 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-debug-kvm 5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-debug-core 5.14.0-284.82.1.rt14.367.el9_2, +6 more
    fixed: vendor fix RHSA-2024:6268
  • Red Hat Enterprise Linux RT (v. 9) kernel-rt 5.14.0-427.35.1.el9_4, kernel-rt-core 5.14.0-427.35.1.el9_4, kernel-rt-modules 5.14.0-427.35.1.el9_4, kernel-rt-debug-core 5.14.0-427.35.1.el9_4, kernel-rt-modules-core 5.14.0-427.35.1.el9_4, kernel-rt-debug-modules 5.14.0-427.35.1.el9_4, +4 more
    fixed: vendor fix RHSA-2024:6567
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-doc 5.14.0-284.82.1.el9_2
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-25-226-15 updated cvss 0.0

Siemens SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) < 3.1 Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family < 3.1
    affected: fixed in V3.1 support.industry.siemens.com
  • Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family
    not affected

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.