From 8ef0b11af70799f96588c2aca36fff8d5ce25c7b Mon Sep 17 00:00:00 2001 From: Jinjie Ruan Date: Wed, 6 Nov 2024 09:12:38 +0800 Subject: cpufreq: CPPC: Fix wrong return value in cppc_get_cpu_cost() [ Upstream commit be392aa80f1e5b0b65ccc2a540b9304fefcfe3d8 ] cppc_get_cpu_cost() return 0 if the policy is NULL. Then in em_compute_costs(), the later zero check for cost is not valid as cost is uninitialized. As Quentin pointed out, kernel energy model core check the return value of get_cost() first, so if the callback failed it should tell the core. Return -EINVAL to fix it. Fixes: 1a1374bb8c59 ("cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost()") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/all/c4765377-7830-44c2-84fa-706b6e304e10@stanley.mountain/ Signed-off-by: Jinjie Ruan Suggested-by: Quentin Perret Signed-off-by: Viresh Kumar Signed-off-by: Sasha Levin --- drivers/cpufreq/cppc_cpufreq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 0a2c21d5bc1c..fd02702de504 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -493,7 +493,7 @@ static int cppc_get_cpu_cost(struct device *cpu_dev, unsigned long KHz, policy = cpufreq_cpu_get_raw(cpu_dev->id); if (!policy) - return 0; + return -EINVAL; cpu_data = policy->driver_data; perf_caps = &cpu_data->perf_caps; -- cgit v1.2.3