CVE-2024-56531: In the Linux kernel, the following vulnerability has been resolved: ALSA: caiaq: Use snd_card_free_when_closed() at disconnection The USB disconnect...

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.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.21%

11.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	>= 2.6.22, < 4.19.325
Linux	Linux Kernel	>= 4.20, < 5.4.287
Linux	Linux Kernel	>= 5.5, < 5.10.231
Linux	Linux Kernel	>= 5.11, < 5.15.174
Linux	Linux Kernel	>= 5.16, < 6.1.120
Linux	Linux Kernel	>= 6.2, < 6.6.64
Linux	Linux Kernel	>= 6.7, < 6.11.11
Linux	Linux Kernel	>= 6.12, < 6.12.2

References

Timeline

Published: Dec 27, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-56531?

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.

How severe is CVE-2024-56531?

CVE-2024-56531 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.

How do I fix CVE-2024-56531?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.