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Fencer Vulns
high 7.8

CVE-2024-43892 json

memcg: protect concurrent access to mem_cgroup_idr

published 2024-08-26 2 y ago modified 2026-08-05 3 mo ago also EUVD-2024-40542

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

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

memcg: protect concurrent access to mem_cgroup_idr

Commit 73f576c04b94 ("mm: memcontrol: fix cgroup creation failure after many small jobs") decoupled the memcg IDs from the CSS ID space to fix the cgroup creation failures. It introduced IDR to maintain the memcg ID space. The IDR depends on external synchronization mechanisms for modifications. For the mem_cgroup_idr, the idr_alloc() and idr_replace() happen within css callback and thus are protected through cgroup_mutex from concurrent modifications. However idr_remove() for mem_cgroup_idr was not protected against concurrency and can be run concurrently for different memcgs when they hit their refcnt to zero. Fix that.

We have been seeing list_lru based kernel crashes at a low frequency in our fleet for a long time. These crashes were in different part of list_lru code including list_lru_add(), list_lru_del() and reparenting code. Upon further inspection, it looked like for a given object (dentry and inode), the super_block's list_lru didn't have list_lru_one for the memcg of that object. The initial suspicions were either the object is not allocated through kmem_cache_alloc_lru() or somehow memcg_list_lru_alloc() failed to allocate list_lru_one() for a memcg but returned success. No evidence were found for these cases.

Looking more deeply, we started seeing situations where valid memcg's id is not present in mem_cgroup_idr and in some cases multiple valid memcgs have same id and mem_cgroup_idr is pointing to one of them. So, the most reasonable explanation is that these situations can happen due to race between multiple idr_remove() calls or race between idr_alloc()/idr_replace() and idr_remove(). These races are causing multiple memcgs to acquire the same ID and then offlining of one of them would cleanup list_lrus on the system for all of them. Later access from other memcgs to the list_lru cause crashes due to missing list_lru_one.

Patch / fix

  • Linux Linux 4.5, 4.7, 5.10.226, 5.15.167, 6.1.110, 6.6.46, 6.10.5, 6.11
  • linux Debian 12 6.1.112-1
  • linux Debian 14, Debian 13 6.10.6-1

debian advisories DEBIAN-CVE-2024-43892

  • linux Ubuntu 20.04 LTS 5.4.0-204.224
  • linux Ubuntu 22.04 LTS 5.15.0-125.135
  • linux Ubuntu 24.04 LTS 6.8.0-50.51
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1137.147
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1072.78
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1020.22
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1141.150
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1071.79

ubuntu advisories UBUNTU-CVE-2024-43892

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 5.14.0-503.11.1.el9_5
  • rv RHEL 9 5.14.0-503.11.1.el9_5
  • perf RHEL 9 5.14.0-503.11.1.el9_5
  • rtla RHEL 9 5.14.0-503.11.1.el9_5
  • bpftool RHEL 9 7.4.0-503.11.1.el9_5
  • libperf RHEL 9 5.14.0-503.11.1.el9_5
  • kernel-rt RHEL 9 5.14.0-503.11.1.el9_5
  • kernel-64k RHEL 9 5.14.0-503.11.1.el9_5

red hat advisories RHSA-2025:3021RHSA-2024:9315RHSA-2024:8870RHSA-2024:8856

  • kernel-rt Linux Micro 6.0 6.4.0-10.1
  • kernel-source-rt Linux Micro 6.0 6.4.0-10.1
  • kernel-livepatch-MICRO-6-0-RT_Update_2 Linux Micro 6.0 1-1.1
  • kernel-source Linux Micro 6.0 6.4.0-19.1
  • kernel-default Linux Micro 6.0 6.4.0-19.1
  • kernel-kvmsmall Linux Micro 6.0 6.4.0-19.1
  • kernel-default-base Linux Micro 6.0 6.4.0-17.1.1.51
  • kernel-livepatch-MICRO-6-0_Update_2 Linux Micro 6.0 1-1.1

suse advisories SUSE-SU-2025:20047-1SUSE-SU-2025:20044-1SUSE-SU-2024:3483-1SUSE-SU-2024:3383-1SUSE-SU-2024:3252-1SUSE-SU-2024:3251-1

  • kernel AlmaLinux 8 4.18.0-553.27.1.el8_10
  • perf AlmaLinux 8 4.18.0-553.27.1.el8_10
  • bpftool AlmaLinux 8 4.18.0-553.27.1.el8_10
  • kernel-core AlmaLinux 8 4.18.0-553.27.1.el8_10
  • kernel-tools AlmaLinux 8 4.18.0-553.27.1.el8_10
  • python3-perf AlmaLinux 8 4.18.0-553.27.1.el8_10
  • kernel-modules AlmaLinux 8 4.18.0-553.27.1.el8_10
  • kernel-zfcpdump AlmaLinux 8 4.18.0-553.27.1.el8_10

almalinux advisories ALSA-2024:8856ALSA-2024:8870

  • kernel-rt Rocky Linux 8 4.18.0-553.27.1.rt7.368.el8_10
  • kernel Rocky Linux 8 4.18.0-553.27.1.el8_10

rocky linux advisories RLSA-2024:8870RLSA-2024:8856

  • kernel CBL-Mariner 2.0 5.15.167.1-1

azure linux advisories AZL-48662

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-2024-43892 updated cvss 4.7

kernel: memcg: protect concurrent access to mem_cgroup_idr

  • 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: no fix planned “Out of support scope”
  • Red Hat CodeReady Linux Builder (v. 9) libperf 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-s390x 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-x86_64 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-aarch64 5.14.0-503.11.1.el9_5, kernel-debuginfo-common-ppc64le 5.14.0-503.11.1.el9_5
    fixed: vendor fix RHSA-2024:9315
  • Red Hat CodeReady Linux Builder EUS (v.9.4) libperf 5.14.0-427.60.1.el9_4, kernel-debuginfo-common-s390x 5.14.0-427.60.1.el9_4, kernel-debuginfo-common-x86_64 5.14.0-427.60.1.el9_4, kernel-debuginfo-common-aarch64 5.14.0-427.60.1.el9_4, kernel-debuginfo-common-ppc64le 5.14.0-427.60.1.el9_4
    fixed: vendor fix RHSA-2025:3021
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-503.11.1.el9_5, perf 5.14.0-503.11.1.el9_5, rtla 5.14.0-503.11.1.el9_5, kernel-devel-matched 5.14.0-503.11.1.el9_5, kernel-64k-devel-matched 5.14.0-503.11.1.el9_5, kernel-debug-devel-matched 5.14.0-503.11.1.el9_5, +6 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat Enterprise Linux AppStream EUS (v.9.4) rv 5.14.0-427.60.1.el9_4, perf 5.14.0-427.60.1.el9_4, rtla 5.14.0-427.60.1.el9_4, kernel-devel-matched 5.14.0-427.60.1.el9_4, kernel-64k-devel-matched 5.14.0-427.60.1.el9_4, kernel-debug-devel-matched 5.14.0-427.60.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:3021
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-553.27.1.el8_10, kernel 4.18.0-553.27.1.el8_10, bpftool 4.18.0-553.27.1.el8_10, kernel-core 4.18.0-553.27.1.el8_10, kernel-tools 4.18.0-553.27.1.el8_10, python3-perf 4.18.0-553.27.1.el8_10, +15 more
    fixed: vendor fix RHSA-2024:8856
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.4.0-503.11.1.el9_5, kernel 5.14.0-503.11.1.el9_5, kernel-64k 5.14.0-503.11.1.el9_5, kernel-core 5.14.0-503.11.1.el9_5, kernel-tools 5.14.0-503.11.1.el9_5, python3-perf 5.14.0-503.11.1.el9_5, +29 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool 7.3.0-427.60.1.el9_4, kernel 5.14.0-427.60.1.el9_4, kernel-64k 5.14.0-427.60.1.el9_4, kernel-core 5.14.0-427.60.1.el9_4, kernel-tools 5.14.0-427.60.1.el9_4, python3-perf 5.14.0-427.60.1.el9_4, +28 more
    fixed: vendor fix RHSA-2025:3021
show 8 more
  • Red Hat Enterprise Linux CRB (v. 8) kernel-debuginfo-common-x86_64 4.18.0-553.27.1.el8_10, kernel-debuginfo-common-aarch64 4.18.0-553.27.1.el8_10, kernel-debuginfo-common-ppc64le 4.18.0-553.27.1.el8_10
    fixed: vendor fix RHSA-2024:8856
  • Red Hat Enterprise Linux NFV (v. 8) kernel-rt 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-kvm 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-core 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-modules 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-debug-kvm 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-debug-core 4.18.0-553.27.1.rt7.368.el8_10, +4 more
    fixed: vendor fix RHSA-2024:8870
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-503.11.1.el9_5, kernel-rt-core 5.14.0-503.11.1.el9_5, kernel-rt-modules 5.14.0-503.11.1.el9_5, kernel-rt-debug-core 5.14.0-503.11.1.el9_5, kernel-rt-modules-core 5.14.0-503.11.1.el9_5, kernel-rt-debug-modules 5.14.0-503.11.1.el9_5, +4 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt 5.14.0-427.60.1.el9_4, kernel-rt-core 5.14.0-427.60.1.el9_4, kernel-rt-modules 5.14.0-427.60.1.el9_4, kernel-rt-debug-core 5.14.0-427.60.1.el9_4, kernel-rt-modules-core 5.14.0-427.60.1.el9_4, kernel-rt-debug-modules 5.14.0-427.60.1.el9_4, +4 more
    fixed: vendor fix RHSA-2025:3021
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-503.11.1.el9_5, kernel-rt-kvm 5.14.0-503.11.1.el9_5, kernel-rt-core 5.14.0-503.11.1.el9_5, kernel-rt-modules 5.14.0-503.11.1.el9_5, kernel-rt-debug-kvm 5.14.0-503.11.1.el9_5, kernel-rt-debug-core 5.14.0-503.11.1.el9_5, +6 more
    fixed: vendor fix RHSA-2024:9315
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt 5.14.0-427.60.1.el9_4, kernel-rt-kvm 5.14.0-427.60.1.el9_4, kernel-rt-core 5.14.0-427.60.1.el9_4, kernel-rt-modules 5.14.0-427.60.1.el9_4, kernel-rt-debug-kvm 5.14.0-427.60.1.el9_4, kernel-rt-debug-core 5.14.0-427.60.1.el9_4, +6 more
    fixed: vendor fix RHSA-2025:3021
  • Red Hat Enterprise Linux RT (v. 8) kernel-rt 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-core 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-modules 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-debug-core 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-debug-modules 4.18.0-553.27.1.rt7.368.el8_10, kernel-rt-modules-extra 4.18.0-553.27.1.rt7.368.el8_10, +2 more
    fixed: vendor fix RHSA-2024:8870
  • Red Hat CodeReady Linux Builder (v. 9) kernel-cross-headers 5.14.0-503.11.1.el9_5 Red Hat Enterprise Linux AppStream (v. 9) kernel-headers 5.14.0-503.11.1.el9_5
    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 SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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

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.