CVE-2026-31775 Linux CVE debrief

Who should care

Linux system administrators and security teams responsible for patching and vulnerability management. They should assess exposure and prioritize patching for kernel versions 6.19 and 7.0 RCs. Verify patch deployment for Linux kernel versions 6.19 and 7.0 RCs. Assess exposure of Linux systems to specific hardware configurations.

Why it matters

A medium-severity Linux kernel vulnerability was addressed, which could cause a kernel crash on certain hardware configurations. Linux system administrators and security teams should assess exposure and prioritize patching for kernel versions 6.19 and 7.0 RCs.

• Verify patch deployment for Linux kernel versions 6.19 and 7.0 RCs
• Assess exposure of Linux systems to specific hardware configurations
• Prioritize patching for medium-severity vulnerability

Technical summary

The Linux kernel vulnerability was caused by incorrect enumeration of SPDIF1 at DAIO initialization, leading to a kernel crash on certain hardware configurations. This was due to the recent refactoring of xfi driver changing the assignment of atc->daios[] at atc_get_resources(). 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. The patch addresses the root cause of the regression, simply by skipping the incorrect SPDIF1 type in the parser loop.

Defensive priority

Medium-priority patching recommended for Linux kernel versions 6.19 and 7.0 RCs.

Recommended defensive actions

• Apply patches from Linux kernel stable branches
• Inventory Linux systems for kernel versions 6.19 and 7.0 RCs
• Verify system exposure to specific hardware configurations
• Verify patch deployment for Linux kernel versions 6.19 and 7.0 RCs
• Assess exposure of Linux systems to specific hardware configurations
• Prioritize patching for medium-severity vulnerability
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The vulnerability was introduced by refactoring of the xfi driver, changing the assignment of atc->daios[] at atc_get_resources(). 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.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.