CVE-2026-89991

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description An infinite loop can occur in the pcpu freelist push() function when the system is configured with only one possible CPU (such as when CONFIG SMP=n or nr cpus=1). This happens if a Non-Maskable Interrupt (NMI) re-enters pcpu freelist push() while the interrupted context already holds the freelist lock for that CPU. In this scenario, the fallback loop fails to find other CPUs to examine, and since raw res spin lock() returns -EDEADLK to prevent recursive acquisition on the same CPU, the process cannot make progress and loops indefinitely.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.