CVE-2022-49377: blk-mq: don't touch ->tagset in blk_mq_get_sq_hctx

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: blk-mq: don't touch ->tagset in blk_mq_get_sq_hctx blk_mq_run_hw_queues() could be run when there isn't queued request and after queue is cleaned up, at that time tagset is freed, because tagset lifetime is covered by driver, and often freed after blk_cleanup_queue() returns. So don't touch ->tagset for figuring out current default hctx by the mapping built in request queue, so use-after-free on tagset can be avoided. Meantime this way should be fast than retrieving mapping from tagset.

Affected products

Linux kernel: from 5.12 before 5.15.47; from 5.16 before 5.17.15; from 5.18 before 5.18.4 — fixed in 5.15.47, 5.17.15, 5.18.4

How to fix

Upgrade to a fixed version: Linux kernel 5.15.47, 5.17.15, 5.18.4. Check the vendor advisory for mitigations.

References

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