3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: James Morse <james.morse@xxxxxxx> commit 7d64f82cceb21e6d95db312d284f5f195e120154 upstream. When removing a GHES device notified by SCI, list_del_rcu() is used, ghes_remove() should call synchronize_rcu() before it goes on to call kfree(ghes), otherwise concurrent RCU readers may still hold this list entry after it has been freed. Signed-off-by: James Morse <james.morse@xxxxxxx> Reviewed-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Fixes: 81e88fdc432a (ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type support) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/apei/ghes.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -1078,6 +1078,7 @@ static int ghes_remove(struct platform_d if (list_empty(&ghes_sci)) unregister_acpi_hed_notifier(&ghes_notifier_sci); mutex_unlock(&ghes_list_mutex); + synchronize_rcu(); break; case ACPI_HEST_NOTIFY_NMI: ghes_nmi_remove(ghes);