CVE-2026-23157
Description
A deadlock vulnerability was found in the Linux kernel's Btrfs filesystem when used with cgroups that have low memory/dirty page limits. Btrfs has an internal 32MiB threshold before writing back btree metadata, but if a cgroup's dirty limit is lower (e.g., 16MB), processes can become stuck indefinitely in balance_dirty_pages() waiting for dirty pages to be written back that Btrfs refuses to flush.
Statement
This deadlock affects systems using Btrfs with memory cgroups that have restrictive dirty page limits. Over 1000 processes can become stuck, causing system hangs. The issue primarily impacts containerized environments with strict memory constraints. Newer kernels (6.18+) have mitigations via AS_KERNEL_FILE, but LTS kernels remain vulnerable.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Other); DoS: Crash, Exit, or Restart
Each thread of execution will "hang" and prevent tasks from completing. In some cases, CPU consumption may occur if a lock check occurs in a tight loop.
Frequently Asked Questions
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