Skip to contentSkip to conversation

Patch "thermal: cpu_cooling: fix out of bounds access in time_in_idle" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Mar 7, 2016

Subsystems (2)
Stable branch Thermal
lore
Share & tools
lore

[email protected]

author maintainer Applied
#0 lore raw

This is a note to let you know that I've just added the patch titled

thermal: cpu_cooling: fix out of bounds access in time_in_idle

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
thermal-cpu_cooling-fix-out-of-bounds-access-in-time_in_idle.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From a53b8394ec3c67255928df6ee9cc99dd1cd452e3 Mon Sep 17 00:00:00 2001

From: Javi Merino <[email protected]>
Date: Thu, 11 Feb 2016 12:00:51 +0000
Subject: thermal: cpu_cooling: fix out of bounds access in time_in_idle

From: Javi Merino <[email protected]>

commit a53b8394ec3c67255928df6ee9cc99dd1cd452e3 upstream.

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 <[email protected]>
Cc Amit Daniel Kachhap <[email protected]>
Cc Zhang Rui <[email protected]>
Cc Eduardo Valentin <[email protected]>
Tested-by Nicolas Boichat <[email protected]>
Acked-by Viresh Kumar <[email protected]>
Signed-off-by Javi Merino <[email protected]>
Signed-off-by Eduardo Valentin <[email protected]>
Signed-off-by Greg Kroah-Hartman <[email protected]>
---
 drivers/thermal/cpu_cooling.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)
drivers/thermal/cpu_cooling.c +8 -6
@@ -377,26 +377,28 @@ static u32 cpu_power_to_freq(struct cpuf
  * 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(s
 		u32 load;
 
 		if (cpu_online(cpu))
-			load = get_load(cpufreq_device, cpu);
+			load = get_load(cpufreq_device, cpu, i);
 		else
 			load = 0;

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/thermal-cpu_cooling-fix-out-of-bounds-access-in-time_in_idle.patch