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Unscored CVE-2024-42102 EUVD-2024-39934GHSA-3cf4-3gwv-8jwp

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

Published Jul 30, 2024 · Updated May 23, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: kernel Package: linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.15 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.4 Package: linux-aws-5.8 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-aws-6.8 Package: linux-aws-fips Package: linux-aws-hwe Package: linux-azure Package: linux-azure-4.15 Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.15 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.4 Package: linux-azure-5.8 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-6.8 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.2 Package: linux-azure-fips Package: linux-bluefield Package: linux-fips Package: linux-gcp Package: linux-gcp-4.15 Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.15 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.4 Package: linux-gcp-5.8 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gcp-6.8 Package: linux-gcp-fips Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.15 Package: linux-hwe-5.19 Package: linux-hwe-5.4 Package: linux-hwe-5.8 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-6.8 Package: linux-hwe-edge Package: linux-ibm Package: linux-ibm-5.15 Package: linux-ibm-5.4 Package: linux-ibm-6.8 Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-intel-iotg Package: linux-intel-iotg-5.15 Package: linux-iot Package: linux-kvm Package: linux-lowlatency Package: linux-lowlatency-hwe-5.15 Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-lowlatency-hwe-6.8 Package: linux-lts-xenial Package: linux-nvidia Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-nvidia-6.8 Package: linux-nvidia-lowlatency Package: linux-nvidia-tegra Package: linux-nvidia-tegra-5.15 Package: linux-nvidia-tegra-igx Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.15 Package: linux-oracle-5.3 Package: linux-oracle-5.4 Package: linux-oracle-5.8 Package: linux-oracle-6.5 Package: linux-oracle-6.8 Package: linux-raspi Package: linux-raspi-5.4 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.8 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.15 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.5 Package: linux-riscv-6.8 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Package: linux-xilinx Package: linux-xilinx-zynqmp Platform: Linux Ecosystem: Azure Linux Ecosystem: Debian Ecosystem: Ubuntu

Description

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.

Affected products

VendorProductAffectedFixed
Linux Linux 4.19.307 – < 4.19.318, 5.4.269 – < 5.4.280, 5.10.210 – < 5.10.222, 5.15.149 – < 5.15.163, 6.1.79 – < 6.1.98, 6.6.18 – < 6.6.39, 6.7.6 – < 6.8, 6.8 4.19.318

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 6.9.9-1 —
Debian 13 linux 6.9.9-1 —
Debian 12 linux 6.1.98-1 —
Debian 11 linux 5.10.223-1 DSA-5747-1
Debian 11 linux-6.1 6.1.119-1~deb11u1 DLA-4008-1
ReleasePackageFixed inAdvisory
Ubuntu Nvidia-BlueField 22.04 LTS linux-bluefield 5.15.0-1052.54 —
Ubuntu 24.04 LTS linux 6.8.0-48.48 USN-7089-1
Ubuntu 24.04 LTS linux-aws 6.8.0-1018.20 USN-7089-3
Ubuntu 24.04 LTS linux-azure 6.8.0-1017.20 USN-7089-2
Ubuntu 24.04 LTS linux-gcp +1 6.8.0-1017.19 USN-7095-1, USN-7089-2
Ubuntu 24.04 LTS linux-gke 6.8.0-1013.17 USN-7089-6
Ubuntu 24.04 LTS linux-gkeop 6.8.0-1002.4 USN-7156-1
Ubuntu 24.04 LTS linux-ibm 6.8.0-1015.15 USN-7089-2
Ubuntu 24.04 LTS linux-lowlatency 6.8.0-48.48.3 USN-7089-7
Ubuntu 24.04 LTS linux-nvidia-lowlatency 6.8.0-1017.19.1 USN-7095-1
Ubuntu 24.04 LTS linux-oem-6.8 6.8.0-1016.16 USN-7089-4
Ubuntu 24.04 LTS linux-oracle 6.8.0-1015.16 USN-7089-3
Ubuntu 24.04 LTS linux-raspi 6.8.0-1014.16 USN-7089-5
Ubuntu 24.04 LTS linux-riscv 6.8.0-48.48.1 —
Ubuntu 24.04 LTS linux-xilinx 6.8.0-1009.10 —
Ubuntu 22.04 LTS linux +1 5.15.0-121.131 USN-7007-3, USN-7007-1
Ubuntu 22.04 LTS linux-aws 5.15.0-1069.75 USN-7007-1
Ubuntu 22.04 LTS linux-aws-6.8 6.8.0-1018.19~22.04.1 USN-7089-3
Ubuntu 22.04 LTS linux-azure 5.15.0-1072.81 USN-7009-1
Ubuntu 22.04 LTS linux-azure-6.8 6.8.0-1017.20~22.04.1 USN-7090-1
Ubuntu 22.04 LTS linux-azure-fde 5.15.0-1072.81.1 USN-7009-1
Ubuntu 22.04 LTS linux-gcp 5.15.0-1068.76 USN-7007-1
Ubuntu 22.04 LTS linux-gcp-6.8 +1 6.8.0-1017.19~22.04.1 USN-7095-1, USN-7089-1
Ubuntu 22.04 LTS linux-gke 5.15.0-1066.72 USN-7007-1
Ubuntu 22.04 LTS linux-gkeop 5.15.0-1052.59 USN-7007-1
Ubuntu 22.04 LTS linux-hwe-6.8 6.8.0-48.48~22.04.1 USN-7089-1
Ubuntu 22.04 LTS linux-ibm +1 5.15.0-1062.65 USN-7007-1
Ubuntu 22.04 LTS linux-ibm-6.8 +1 6.8.0-1015.15~22.04.1 USN-7089-3
Ubuntu 22.04 LTS linux-intel-iotg 5.15.0-1064.70 USN-7007-1
Ubuntu 22.04 LTS linux-kvm 5.15.0-1066.71 USN-7007-1
Ubuntu 22.04 LTS linux-lowlatency-hwe-6.8 6.8.0-48.48.3~22.04.1 USN-7089-7
Ubuntu 22.04 LTS linux-nvidia 5.15.0-1064.65 USN-7007-1
Ubuntu 22.04 LTS linux-nvidia-tegra 5.15.0-1028.28 —
Ubuntu 22.04 LTS linux-nvidia-tegra-igx 5.15.0-1016.16 —
Ubuntu 22.04 LTS linux-oracle 5.15.0-1067.73 USN-7007-1
Ubuntu 22.04 LTS linux-riscv +31 No fix yet —
Ubuntu 22.04 LTS linux-riscv-6.8 6.8.0-48.48.1~22.04.2 —
Ubuntu 22.04 LTS linux-xilinx-zynqmp 5.15.0-1035.39 USN-7019-1
Ubuntu 20.04 LTS linux 5.4.0-195.215 USN-7003-1
Ubuntu 20.04 LTS linux-aws 5.4.0-1132.142 USN-7003-1
Ubuntu 20.04 LTS linux-aws-5.15 5.15.0-1069.75~20.04.1 USN-7007-1
Ubuntu 20.04 LTS linux-azure 5.4.0-1137.144 USN-7003-1
Ubuntu 20.04 LTS linux-azure-5.15 5.15.0-1072.81~20.04.1 USN-7009-1
Ubuntu 20.04 LTS linux-azure-fde-5.15 5.15.0-1072.81~20.04.1.1 USN-7009-2
Ubuntu 20.04 LTS linux-bluefield 5.4.0-1092.99 USN-7003-1
Ubuntu 20.04 LTS linux-gcp 5.4.0-1136.145 USN-7003-1
Ubuntu 20.04 LTS linux-gcp-5.15 5.15.0-1068.76~20.04.1 USN-7007-1
Ubuntu 20.04 LTS linux-gke +26 No fix yet —
Ubuntu 20.04 LTS linux-gkeop 5.4.0-1099.103 USN-7003-1
Ubuntu 20.04 LTS linux-gkeop-5.15 5.15.0-1052.59~20.04.1 USN-7007-1
Ubuntu 20.04 LTS linux-hwe-5.15 +1 5.15.0-121.131~20.04.1 USN-7007-3, USN-7007-1
Ubuntu 20.04 LTS linux-ibm 5.4.0-1079.84 USN-7003-1
Ubuntu 20.04 LTS linux-ibm-5.15 5.15.0-1062.65~20.04.1 USN-7007-2
Ubuntu 20.04 LTS linux-intel-iotg-5.15 5.15.0-1064.70~20.04.1 USN-7007-1
Ubuntu 20.04 LTS linux-iot 5.4.0-1043.44 USN-7006-1
Ubuntu 20.04 LTS linux-kvm 5.4.0-1120.128 USN-7003-1
Ubuntu 20.04 LTS linux-nvidia-tegra-5.15 5.15.0-1030.30~20.04.1 —
Ubuntu 20.04 LTS linux-oracle 5.4.0-1131.140 USN-7003-1
Ubuntu 20.04 LTS linux-oracle-5.15 5.15.0-1067.73~20.04.1 USN-7007-2
Ubuntu 20.04 LTS linux-raspi 5.4.0-1116.128 USN-7003-4
Ubuntu 20.04 LTS linux-riscv-5.15 5.15.0-1065.69~20.04.1 —
Ubuntu 20.04 LTS linux-xilinx-zynqmp 5.4.0-1051.55 USN-7003-3
Ubuntu 18.04 LTS linux-gcp +13 No fix yet —
Show 11 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Ubuntu Pro Realtime 24.04 LTS linux-raspi-realtime 6.8.0-2013.14 —
Ubuntu Pro Realtime 24.04 LTS linux-realtime 6.8.1-1011.11 —
Ubuntu Pro Realtime 22.04 LTS linux-intel-iot-realtime 5.15.0-1063.65 —
Ubuntu Pro Realtime 22.04 LTS linux-realtime 5.15.0-1070.78 —
Ubuntu Pro Realtime 22.04 LTS linux-realtime-6.8 6.8.1-1011.11~22.04.1 —
Ubuntu Pro FIPS-updates 24.04 LTS linux-fips 6.8.0-78.78+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-aws-fips 5.15.0-1069.75+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-azure-fips 5.15.0-1072.81+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-fips 5.15.0-121.131+fips1 —
Ubuntu Pro FIPS-updates 22.04 LTS linux-gcp-fips 5.15.0-1068.76+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-aws-fips 5.4.0-1132.142+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-azure-fips 5.4.0-1137.144+fips1 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-fips 5.4.0-1106.116 —
Ubuntu Pro FIPS-updates 20.04 LTS linux-gcp-fips 5.4.0-1136.145+fips1 —
Ubuntu Pro FIPS-updates 18.04 LTS linux-fips +3 No fix yet —
Ubuntu Pro FIPS-updates 16.04 LTS linux-fips No fix yet —
Ubuntu Pro 18.04 LTS linux +5 No fix yet —
Ubuntu Pro 18.04 LTS linux-aws-5.4 5.4.0-1132.142~18.04.1 USN-7003-2
Ubuntu Pro 18.04 LTS linux-azure-5.4 5.4.0-1137.144~18.04.1 USN-7003-2
Ubuntu Pro 18.04 LTS linux-gcp-5.4 5.4.0-1136.145~18.04.1 USN-7003-2
Ubuntu Pro 18.04 LTS linux-hwe-5.4 5.4.0-195.215~18.04.1 USN-7003-2
Ubuntu Pro 18.04 LTS linux-ibm-5.4 5.4.0-1079.84~18.04.1 USN-7003-2
Ubuntu Pro 18.04 LTS linux-oracle-5.4 5.4.0-1131.140~18.04.1 USN-7003-2
Ubuntu Pro 18.04 LTS linux-raspi-5.4 5.4.0-1116.128~18.04.1 USN-7003-5
Ubuntu Pro 16.04 LTS linux +7 No fix yet —
Ubuntu Pro 14.04 LTS linux-aws +2 No fix yet —
ReleasePackageFixed inAdvisory
RHEL 9 bpftool 7.3.0-427.35.1.el9_4 RHSA-2024:6567
RHEL 9 rv +64 5.14.0-427.35.1.el9_4 RHSA-2024:6567
Show 1 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
RHEL 9.2 EUS bpftool 7.0.0-284.82.1.el9_2 RHSA-2024:6267
RHEL 9.2 EUS kernel-rt +14 5.14.0-284.82.1.rt14.367.el9_2 RHSA-2024:6268
RHEL 9.2 EUS perf +47 5.14.0-284.82.1.el9_2 RHSA-2024:6267

AlmaLinux

Errata ↗
ReleasePackageFixed inAdvisory
AlmaLinux 9 bpftool 7.3.0-427.35.1.el9_4 ALSA-2024:6567
AlmaLinux 9 rv +60 5.14.0-427.35.1.el9_4 ALSA-2024:6567

Rocky Linux

Errata ↗
ReleasePackageFixed inAdvisory
Rocky Linux 9 kernel 5.14.0-427.35.1.el9_4 RXSA-2024:6567, RLSA-2024:6567
ReleasePackageFixed inAdvisory
SLES 15 SP6 kernel-64kb +6 6.4.0-150600.23.30.1 SUSE-SU-2024:4318-1
SLES 15 SP6 kernel-azure +2 6.4.0-150600.8.20.1 SUSE-SU-2024:4316-1
SLES 15 SP6 kernel-coco +3 6.4.0-15061.9.coco15sp6.1 SUSE-SU-2024:4387-1
SLES 15 SP6 kernel-default-base 6.4.0-150600.23.30.1.150600.12.12.6 SUSE-SU-2024:4318-1
Show 4 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
SLE Micro 6.1 kernel-default-base 6.4.0-24.1.21.4 SUSE-SU-2025:20247-1
SLE Micro 6.1 kernel-livepatch-MICRO-6-0-RT_Update_4 1-1.1 SUSE-SU-2025:20246-1
SLE Micro 6.1 kernel-livepatch-MICRO-6-0_Update_4 1-1.2 SUSE-SU-2025:20247-1
SLE Micro 6.1 kernel-rt +1 6.4.0-22.1 SUSE-SU-2025:20246-1
SLE Micro 6.1 kernel-source +2 6.4.0-24.1 SUSE-SU-2025:20247-1
SLE Micro 6.0 kernel-default-base 6.4.0-24.1.21.4 SUSE-SU-2025:20164-1
SLE Micro 6.0 kernel-livepatch-MICRO-6-0-RT_Update_4 1-1.1 SUSE-SU-2025:20163-1
SLE Micro 6.0 kernel-livepatch-MICRO-6-0_Update_4 1-1.2 SUSE-SU-2025:20164-1
SLE Micro 6.0 kernel-rt +1 6.4.0-22.1 SUSE-SU-2025:20163-1
SLE Micro 6.0 kernel-source +2 6.4.0-24.1 SUSE-SU-2025:20164-1
SLE Live Patching 15 SP6 kernel-default 6.4.0-150600.23.30.1 SUSE-SU-2024:4318-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6-RT_Update_6 1-150600.1.3.1 SUSE-SU-2024:4314-1
SLE Live Patching 15 SP6 kernel-livepatch-SLE15-SP6_Update_6 1-150600.13.3.5 SUSE-SU-2024:4318-1
SUSE Real Time Module 15 SP6 kernel-rt +3 6.4.0-150600.10.20.1 SUSE-SU-2024:4314-1
ReleasePackageFixed inAdvisory
openSUSE Leap 15.6 dtb-aarch64 +10 6.4.0-150600.23.30.1 SUSE-SU-2024:4318-1
openSUSE Leap 15.6 kernel-azure +2 6.4.0-150600.8.20.1 SUSE-SU-2024:4316-1
openSUSE Leap 15.6 kernel-default-base 6.4.0-150600.23.30.1.150600.12.12.6 SUSE-SU-2024:4318-1
openSUSE Leap 15.6 kernel-rt +3 6.4.0-150600.10.20.1 SUSE-SU-2024:4314-1

Amazon Linux

ReleasePackageFixed inAdvisory
Amazon Linux 2023 kernel-livepatch-6.1.102-108.177 1.0-0.amzn2023 ALAS2023-2024-679
Amazon Linux 2023 perf +14 6.1.102-108.177.amzn2023 ALAS2023-2024-679
Amazon Linux 2 kernel-livepatch-4.14.352-267.564 1.0-0.amzn2 ALAS2-2025-2778
Amazon Linux 2 perf +8 4.14.352-267.564.amzn2 ALAS2-2025-2778

Azure Linux

ReleasePackageFixed inAdvisory
Azure Linux 2 (CBL-Mariner) kernel 5.15.164.1-1 —

Oracle Linux

ReleasePackageFixed inAdvisory
Oracle Linux 9 bpftool 7.3.0-427.35.1.el9_4 ELSA-2024-6567
Oracle Linux 9 rv +27 5.14.0-427.35.1.el9_4 ELSA-2024-6567

Advisories 45

References