CVE-2026-64070

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

Description A preempt count leak exists in the powerpc/hv-gpci component. Four sysfs show() callbacks—processor bus topology show(), processor config show(), affinity domain via virtual processor show(), and affinity domain via domain show()—utilize get cpu var(hv gpci reqb), which invokes preempt disable(), but fail to call the corresponding put cpu var() upon successful reads. In kernels with CONFIG PREEMPT=y, repeated reads increase the preempt count, causing the system to return to userspace with preemption still disabled. This leads to a SIGSEGV during the next user-mode page fault and can trigger a scheduling while atomic bug during the coredump process.

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