From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javi Merino Subject: [PATCH] thermal: cpu_cooling: fix out of bounds access in time_in_idle Date: Thu, 11 Feb 2016 12:00:51 +0000 Message-ID: <1455192051-6430-1-git-send-email-javi.merino@arm.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: akpm@linux-foundation.org Cc: rui.zhang@intel.com, edubezval@gmail.com, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, drinkcat@chromium.org, Javi Merino , Amit Daniel Kachhap List-Id: linux-pm@vger.kernel.org In __cpufreq_cooling_register() we allocate the arrays for time_in_idle and time_in_idle_timestamp to be as big as the number of cpus in this cpufreq device. However, in get_load() we access this array using the cpu number as index, which can result in an out of bound access. Index time_in_idle{,_timestamp} using the index in the cpufreq_device's allowed_cpus mask, as we do for the load_cpu array in cpufreq_get_requested_power() Reported-by: Nicolas Boichat Cc: Amit Daniel Kachhap Cc: Zhang Rui Cc: Eduardo Valentin Tested-by: Nicolas Boichat Acked-by: Viresh Kumar Signed-off-by: Javi Merino --- Hi Andrew, This patch fixes an out of bounds access found by Nicolas Boichat using KASAN. It is acked by Viresh, comaintainer of the cpu cooling device and tested by the reporter. It's been in the list[0] for more than a month, I've pinged the thermal maintainers three times but they haven't replied. Can you merge it via your tree? Thanks, Javi drivers/thermal/cpu_cooling.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c index e3fbc5a5d88f..bd1bab9eade0 100644 --- a/drivers/thermal/cpu_cooling.c +++ b/drivers/thermal/cpu_cooling.c @@ -377,26 +377,28 @@ static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_device, * get_load() - get load for a cpu since last updated * @cpufreq_device: &struct cpufreq_cooling_device for this cpu * @cpu: cpu number + * @cpu_idx: index of the cpu in cpufreq_device->allowed_cpus * * Return: The average load of cpu @cpu in percentage since this * function was last called. */ -static u32 get_load(struct cpufreq_cooling_device *cpufreq_device, int cpu) +static u32 get_load(struct cpufreq_cooling_device *cpufreq_device, int cpu, + int cpu_idx) { u32 load; u64 now, now_idle, delta_time, delta_idle; now_idle = get_cpu_idle_time(cpu, &now, 0); - delta_idle = now_idle - cpufreq_device->time_in_idle[cpu]; - delta_time = now - cpufreq_device->time_in_idle_timestamp[cpu]; + delta_idle = now_idle - cpufreq_device->time_in_idle[cpu_idx]; + delta_time = now - cpufreq_device->time_in_idle_timestamp[cpu_idx]; if (delta_time <= delta_idle) load = 0; else load = div64_u64(100 * (delta_time - delta_idle), delta_time); - cpufreq_device->time_in_idle[cpu] = now_idle; - cpufreq_device->time_in_idle_timestamp[cpu] = now; + cpufreq_device->time_in_idle[cpu_idx] = now_idle; + cpufreq_device->time_in_idle_timestamp[cpu_idx] = now; return load; } @@ -598,7 +600,7 @@ static int cpufreq_get_requested_power(struct thermal_cooling_device *cdev, u32 load; if (cpu_online(cpu)) - load = get_load(cpufreq_device, cpu); + load = get_load(cpufreq_device, cpu, i); else load = 0; -- 1.9.1