CVE-2024-56531: Linux kernel · ALSA: caiaq: Use snd_card_free_when_closed() at disconnection
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.4.0-1142.152~18.04.1 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:14 UTC
- Patch
- Available – fixed in 5.4.0-1142.152~18.04.1, 5.4.0-1147.154~18.04.1, 5.4.0-1145.154~18.04.1 +82
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Dec 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7310-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7391-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7392-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7393-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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.
References
- ubuntu.com/security/CVE-2024-56531 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-56531 (opens in a new tab)
- git.kernel.org/linus/b04dcbb7f7b1908806b7dc22671cdbe78ff2b82c (opens in a new tab)
- git.kernel.org/stable/c/237f3faf0177bdde728fa3106d730d806436aa4d (opens in a new tab)
- git.kernel.org/stable/c/3993edf44d3df7b6e8c753eac6ac8783473fcbab (opens in a new tab)
- git.kernel.org/stable/c/4507a8b9b30344c5ddd8219945f446d47e966a6d (opens in a new tab)
- git.kernel.org/stable/c/4dd821dcbfcecf7af6a08370b0b217cde2818acf (opens in a new tab)
- git.kernel.org/stable/c/a3f9314752dbb6f6aa1f0f2b4c58243bda800738 (opens in a new tab)
- git.kernel.org/stable/c/b04dcbb7f7b1908806b7dc22671cdbe78ff2b82c (opens in a new tab)
- git.kernel.org/stable/c/cadf1d8e9ddcd74584ec961aeac14ac549b261d8 (opens in a new tab)
- git.kernel.org/stable/c/dd0de8cb708951cebf727aa045e8242ba651bb52 (opens in a new tab)
- git.kernel.org/stable/c/ebad462eec93b0f701dfe4de98990e7355283801 (opens in a new tab)
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7310-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)