CVE-2026-23157

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.

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.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.