CVE-2026-31775 ALSA: ctxfi: Don't enumerate SPDIF1 at DAIO initialization
A missing check in the ALSA ctxfi driver causes a kernel crash on specific hardware, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31775?
CVE-2026-31775 is a medium-severity vulnerability in Linux kernel, published on 1 May 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ctxfi: Don't enumerate SPDIF1 at DAIO initialization
The recent refactoring of xfi driver changed the assignment of atc->daios[] at atc_get_resources(); now it loops over all enum DAIOTYP entries while it looped formerly only a part of them. The problem is that the last entry, SPDIF1, is a special type that is used only for hw20k1 CTSB073X model (as a replacement of SPDIFIO), and there is no corresponding definition for hw20k2. Due to the lack of the info, it caused a kernel crash on hw20k2, which was already worked around by the commit b045ab3dff97 ("ALSA: ctxfi: Fix missing SPDIFI1 index handling").
This patch addresses the root cause of the regression above properly, simply by skipping the incorrect SPDIF1 type in the parser loop.
For making the change clearer, the code is slightly arranged, too.
Which versions are affected by CVE-2026-31775?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31775?
Apply the vendor's patch.
Is CVE-2026-31775 being exploited?
There is no known exploitation of CVE-2026-31775 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-31775, DEBIAN-CVE-2026-31775, GHSA-h9h9-phrr-4q27, UBUNTU-CVE-2026-31775.