CVE-2026-80626

Descripción

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.