CVE-2022-49411: bfq: Make sure bfqg for which we are queueing requests is online

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-26 · updated 2026-06-17
Weakness: CWE-416

Description

In the Linux kernel, the following vulnerability has been resolved: bfq: Make sure bfqg for which we are queueing requests is online Bios queued into BFQ IO scheduler can be associated with a cgroup that was already offlined. This may then cause insertion of this bfq_group into a service tree. But this bfq_group will get freed as soon as last bio associated with it is completed leading to use after free issues for service tree users. Fix the problem by making sure we always operate on online bfq_group. If the bfq_group associated with the bio is not online, we pick the first online parent.

Affected products

Linux kernel: from 4.12 before 5.4.198; from 5.5 before 5.10.121; from 5.11 before 5.15.46; from 5.16 before 5.17.14; from 5.18 before 5.18.3 — fixed in 5.10.121, 5.15.46, 5.17.14, 5.18.3, 5.4.198

How to fix

Upgrade to a fixed version: Linux kernel 5.10.121, 5.15.46, 5.17.14, 5.18.3. Check the vendor advisory for mitigations.

References

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