CVE-2025-40359: 
Linux Kernel vulnerability analysis and mitigation

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

perf/x86/intel: Fix KASAN global-out-of-bounds warning

When running "perf mem record" command on CWF, the below KASAN global-out-of-bounds warning is seen.

================================================================== BUG: KASAN: global-out-of-bounds in cmt_latency_data+0x176/0x1b0 Read of size 4 at addr ffffffffb721d000 by task dtlb/9850

Call Trace:

kasan_report+0xb8/0xf0 cmt_latency_data+0x176/0x1b0 setup_arch_pebs_sample_data+0xf49/0x2560 intel_pmu_drain_arch_pebs+0x577/0xb00 handle_pmi_common+0x6c4/0xc80

The issue is caused by below code in __grt_latency_data(). The code tries to access x86_hybrid_pmu structure which doesn't exist on non-hybrid platform like CWF.

    WARN_ON_ONCE(hybrid_pmu(event->pmu)->pmu_type == hybrid_big)

So add is_hybrid() check before calling this WARN_ON_ONCE to fix the global-out-of-bounds access issue.