CVE-2024-38384: blk-cgroup: fix list corruption from reorder of WRITE ->lqueued

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-06-24 · updated 2026-08-04
Weakness: CWE-400

Description

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix list corruption from reorder of WRITE ->lqueued __blkcg_rstat_flush() can be run anytime, especially when blk_cgroup_bio_start is being executed. If WRITE of `->lqueued` is re-ordered with READ of 'bisc->lnode.next' in the loop of __blkcg_rstat_flush(), `next_bisc` can be assigned with one stat instance being added in blk_cgroup_bio_start(), then the local list in __blkcg_rstat_flush() could be corrupted. Fix the issue by adding one barrier.

Affected products

Linux kernel: from 6.2 before 6.6.33; from 6.7 before 6.9.4 — fixed in 6.6.33, 6.9.4

How to fix

Upgrade to a fixed version: Linux kernel 6.6.33, 6.9.4. Check the vendor advisory for mitigations.

References

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