CVE-2026-80626

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

powerpc/perf: fix preempt count underflow in fsl_emb_pmu_del

fsl_emb_pmu_del() unconditionally calls put_cpu_var(cpu_hw_events) at

the 'out:' label, but only calls the matching get_cpu_var() after the

'i < 0' early-return check. When event->hw.idx is negative the

function jumps to 'out:' without having taken get_cpu_var(), and the

trailing put_cpu_var() then issues an unmatched preempt_enable(),

underflowing preempt_count.

On a CONFIG_PREEMPT=y kernel preempt_count would underflow and

eventually present as a 'scheduling while atomic' BUG.

Move put_cpu_var() to pair with get_cpu_var() so the percpu access is

correctly bracketed and the 'out:' label only handles perf_pmu_enable.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References