# CVE-2022-48931: configfs: fix a race in configfs\_{,un}register\_subsystem()

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-08-22 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 2.6.16

## Description

In the Linux kernel, the following vulnerability has been resolved: configfs: fix a race in configfs_{,un}register_subsystem() When configfs_register_subsystem() or configfs_unregister_subsystem() is executing link_group() or unlink_group(), it is possible that two processes add or delete list concurrently. Some unfortunate interleavings of them can cause kernel panic. One of cases is: A --> B --> C --> D A <-- B <-- C <-- D delete list_head *B | delete list_head *C --------------------------------|----------------------------------- configfs_unregister_subsystem | configfs_unregister_subsystem unlink_group | unlink_group unlink_obj | unlink_obj list_del_init | list_del_init __list_del_entry | __list_del_entry __list_del | __list_del // next == C | next->prev = prev | | next->prev = prev prev->next = next | | // prev == B | prev->next = next Fix this by adding mutex when calling link_group() or unlink_group(), but parent configfs_subsystem is NULL when config_item is root. So I create a mutex configfs_subsystem_mutex.

## 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.
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## 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/40805099af11f68c5ca7dbcfacf455da8f99f622
- https://git.kernel.org/stable/c/d1654de19d42f513b6cfe955cc77e7f427e05a77
- https://git.kernel.org/stable/c/a37024f7757c25550accdebf49e497ad6ae239fe
- https://git.kernel.org/stable/c/b7e2b91fcb5c78c414e33dc8d50642e307ca0c5a
- https://git.kernel.org/stable/c/a7ab53d3c27dfe83bb594456b9f38a37796ec39b
- https://git.kernel.org/stable/c/e7a66dd2687758718eddd79b542a95cf3aa488cc
- https://git.kernel.org/stable/c/3aadfd46858b1f64d4d6a0654b863e21aabff975
- https://git.kernel.org/stable/c/84ec758fb2daa236026506868c8796b0500c047d

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Page: https://cve.now/CVE-2022-48931
JSON: https://cve.now/api/v1/entries/CVE-2022-48931
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