CVE-2026-80626

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

powerpc/perf: fix preempt count underflow in fslembpmu_del

fslembpmudel() unconditionally calls putcpuvar(cpuhwevents) at the 'out:' label, but only calls the matching getcpuvar() after the 'i < 0' early-return check. When event->hw.idx is negative the function jumps to 'out:' without having taken getcpuvar(), and the trailing putcpuvar() then issues an unmatched preemptenable(), underflowing preempt_count.

On a CONFIGPREEMPT=y kernel preemptcount would underflow and eventually present as a 'scheduling while atomic' BUG.

Move putcpuvar() to pair with getcpuvar() so the percpu access is correctly bracketed and the 'out:' label only handles perfpmuenable.