From 5fbbb90dfdedb9a258550e4e5debd3013266372e Mon Sep 17 00:00:00 2001 From: "Jon Medhurst (Tixy)" Date: Wed, 15 Aug 2012 22:11:00 +0200 Subject: [PATCH] cpuidle: Prevent null pointer dereference in cpuidle_coupled_cpu_notify When a kernel is built to support multiple hardware types it's possible that CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED is set but the hardware the kernel is run on doesn't support cpuidle and therefore doesn't load a driver for it. In this case, when the system is shut down, cpuidle_coupled_cpu_notify() gets called with cpuidle_devices set to NULL. There are quite possibly other circumstances where this situation can also occur and we should check for it. Signed-off-by: Jon Medhurst Signed-off-by: Rafael J. Wysocki --- drivers/cpuidle/coupled.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c index c24dda03c143..3265844839bf 100644 --- a/drivers/cpuidle/coupled.c +++ b/drivers/cpuidle/coupled.c @@ -693,7 +693,7 @@ static int cpuidle_coupled_cpu_notify(struct notifier_block *nb, mutex_lock(&cpuidle_lock); dev = per_cpu(cpuidle_devices, cpu); - if (!dev->coupled) + if (!dev || !dev->coupled) goto out; switch (action & ~CPU_TASKS_FROZEN) { -- 2.20.1