memcg: protect concurrent access to mem_cgroup_idr
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 14 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.4.18 to before 4.5; 4.6.6 to before 4.7 | 4.5, 4.7 | Patch available | CNA |
| Linux | Linux | 4.7 and later | 5.10.226, 5.15.167, 6.1.110, 6.6.46, 6.10.5, 6.11 | Patch available | CNA |
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.5, 4.7
- Fix · CNA Linux (Linux) Fixed in 5.10.226, 5.15.167, 6.1.110, 6.6.46, 6.10.5, 6.11
Red Hat 4 advisories
- RHSA-2025:3021 Released 2025-03-19 · Red Hat rating Moderatekernel security update
- Red Hat CodeReady Linux Builder EUS (v.9.4) kernel-tools-libs-devel-5.14.0-427.60.1.el9_4, libperf-5.14.0-427.60.1.el9_4
- Red Hat Enterprise Linux AppStream EUS (v.9.4) kernel-64k-debug-devel-5.14.0-427.60.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.60.1.el9_4, kernel-64k-devel-5.14.0-427.60.1.el9_4 +11
- 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 +29
- 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-debug-5.14.0-427.60.1.el9_4 +9
- Red Hat Enterprise Linux Real Time for NFV 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-debug-5.14.0-427.60.1.el9_4 +11
- RHSA-2024:9315 Released 2024-11-12 · Red Hat rating Moderatekernel security update
- Red Hat CodeReady Linux Builder (v. 9) kernel-cross-headers-5.14.0-503.11.1.el9_5, kernel-tools-libs-devel-5.14.0-503.11.1.el9_5, libperf-5.14.0-503.11.1.el9_5
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-503.11.1.el9_5, kernel-64k-debug-devel-matched-5.14.0-503.11.1.el9_5, kernel-64k-devel-5.14.0-503.11.1.el9_5 +12
- 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 +30
- 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-debug-5.14.0-503.11.1.el9_5 +9
- Red Hat Enterprise Linux Real Time for NFV (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-debug-5.14.0-503.11.1.el9_5 +11
- RHSA-2024:8856 Released 2024-11-05 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.27.1.el8_10, kernel-4.18.0-553.27.1.el8_10, kernel-abi-stablelists-4.18.0-553.27.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.27.1.el8_10
Show 1 more Red Hat advisories
- RHSA-2024:8870 Released 2024-11-05 · Red Hat rating Moderatekernel-rt security update
- Red Hat Enterprise Linux NFV (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-debug-4.18.0-553.27.1.rt7.368.el8_10 +9
- 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-debug-4.18.0-553.27.1.rt7.368.el8_10 +7
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat CodeReady Linux Builder (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat CodeReady Linux Builder EUS (v.9.4) | Fixed | RHSA-2025:3021 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux AppStream EUS (v.9.4) | Fixed | RHSA-2025:3021 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2024:8856 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.4) | Fixed | RHSA-2025:3021 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2024:8856 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2024:8870 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2024:8870 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux Real Time EUS (v.9.4) | Fixed | RHSA-2025:3021 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) | Fixed | RHSA-2025:3021 |
Not affected: 2 products
- Red Hat CodeReady Linux Builder (v. 9)
- Red Hat Enterprise Linux AppStream (v. 9)
Timeline
- 2026-10-02 Threatist record created from CVE-2024-43892
- 2026-10-03 Alias added: GHSA-hxw3-49vc-4rrp
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 3
More Linux Kernel vulnerabilities
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Sources
- CVE-2024-43892 · CVE Program
- CVE-2024-43892 · NVD
- FIRST EPSS
- GHSA-hxw3-49vc-4rrp · GitHub Advisory Database · CC BY 4.0
- CVE-2024-43892 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences