CVE-2026-46298 addresses a race condition in the Linux kernel's pseries/papr-hvpipe subsystem where concurrent execution of the ioctl or release handlers and an interrupt on the same CPU could lead to a deadlock. The fix involves using spin_lock_irqsave and spin_lock_irqrestore variants to properly synchronize access and prevent deadlocks. This vulnerability affects multiple Linux kernel versions prior to 7.0.0-28.28 and related package versions. The issue was resolved in official Ubuntu kernel updates as part of a broader security update addressing multiple kernel vulnerabilities.

The vulnerability can cause a deadlock in the kernel on affected systems, potentially leading to denial of service due to system hang. There is no indication of confidentiality or integrity impact. The attack requires local access with low privileges and has high complexity, limiting exploitability. No known exploits in the wild have been reported.

A patch is available and has been released by Ubuntu as part of their Linux kernel updates for version 7.0.0-28.28 and later. Users should apply the official kernel updates provided by their distribution and reboot the system to ensure the fix is applied. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be necessary after updating. No additional mitigation steps are required beyond applying the official updates.