From 916b61abba586d950a4d8264e2841cc5ccfa4df1 Mon Sep 17 00:00:00 2001 From: Sumeet Pawnikar Date: Sat, 22 Aug 2026 15:16:57 +0530 Subject: [PATCH] powercap: intel_rapl: Fix kernel panic during PMU unbind rapl_package_add_pmu() fails internally at perf_pmu_register(), and rapl_pmu_update() leaves the global rapl_pmu.pmu structure zero-initialized via memset and returns an error. But any previously probed packages retain has_pmu = true. When the driver is subsequently unbound or removed, rapl_package_remove_pmu_locked() sees has_pmu == true and unconditionally calls perf_pmu_unregister(&rapl_pmu.pmu) on the zeroed-out structure. This attempts a list_del_rcu() on a NULL list head, immediately causing a kernel panic. Fix this by checking if the PMU is actually registered before attempting to unregister it. Signed-off-by: Sumeet Pawnikar Reviewed-by: Abel Vesa [ rjw: Added empty line after the new conditional ] Link: https://patch.msgid.link/20260822094657.12489-1-sumeet4linux@gmail.com Signed-off-by: Rafael J. Wysocki --- drivers/powercap/intel_rapl_common.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/powercap/intel_rapl_common.c b/drivers/powercap/intel_rapl_common.c index 6b7d11a0abc5..0c743a86df76 100644 --- a/drivers/powercap/intel_rapl_common.c +++ b/drivers/powercap/intel_rapl_common.c @@ -1661,7 +1661,9 @@ void rapl_package_remove_pmu_locked(struct rapl_package *rp) return; } - perf_pmu_unregister(&rapl_pmu.pmu); + if (rapl_pmu.registered) + perf_pmu_unregister(&rapl_pmu.pmu); + memset(&rapl_pmu, 0, sizeof(struct rapl_pmu)); } EXPORT_SYMBOL_NS_GPL(rapl_package_remove_pmu_locked, "INTEL_RAPL");