diff mbox

thermal: cpu_cooling: fix out of bounds access in time_in_idle

Message ID 1450529677-23426-1-git-send-email-javi.merino@arm.com (mailing list archive)
State Accepted, archived
Delegated to: Zhang Rui
Headers show

Commit Message

Javi Merino Dec. 19, 2015, 12:54 p.m. UTC
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 <drinkcat@chromium.org>
Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Signed-off-by: Javi Merino <javi.merino@arm.com>
---
 drivers/thermal/cpu_cooling.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

Comments

Viresh Kumar Dec. 21, 2015, 3:19 a.m. UTC | #1
On 19-12-15, 12:54, Javi Merino wrote:
> 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 <drinkcat@chromium.org>
> Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: Zhang Rui <rui.zhang@intel.com>
> Cc: Eduardo Valentin <edubezval@gmail.com>
> Signed-off-by: Javi Merino <javi.merino@arm.com>
> ---
>  drivers/thermal/cpu_cooling.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Javi Merino Jan. 5, 2016, 7:19 p.m. UTC | #2
Eduardo, Rui,

On Mon, Dec 21, 2015 at 08:49:40AM +0530, Viresh Kumar wrote:
> On 19-12-15, 12:54, Javi Merino wrote:
> > 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 <drinkcat@chromium.org>
> > Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com>
> > Cc: Viresh Kumar <viresh.kumar@linaro.org>
> > Cc: Zhang Rui <rui.zhang@intel.com>
> > Cc: Eduardo Valentin <edubezval@gmail.com>
> > Signed-off-by: Javi Merino <javi.merino@arm.com>
> > ---
> >  drivers/thermal/cpu_cooling.c | 14 ++++++++------
> >  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

If there are no more objections, can you pick this up?

Thanks,
Javi
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Javi Merino Jan. 15, 2016, 3:20 p.m. UTC | #3
Eduardo, Rui,

On Tue, Jan 05, 2016 at 07:19:25PM +0000, Javi Merino wrote:
> On Mon, Dec 21, 2015 at 08:49:40AM +0530, Viresh Kumar wrote:
> > On 19-12-15, 12:54, Javi Merino wrote:
> > > 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 <drinkcat@chromium.org>
> > > Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com>
> > > Cc: Viresh Kumar <viresh.kumar@linaro.org>
> > > Cc: Zhang Rui <rui.zhang@intel.com>
> > > Cc: Eduardo Valentin <edubezval@gmail.com>
> > > Signed-off-by: Javi Merino <javi.merino@arm.com>
> > > ---
> > >  drivers/thermal/cpu_cooling.c | 14 ++++++++------
> > >  1 file changed, 8 insertions(+), 6 deletions(-)
> > 
> > Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> 
> If there are no more objections, can you pick this up?

Another gentle ping, can this be merged?

Thanks,
Javi
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Nicolas Boichat Jan. 18, 2016, 2:25 a.m. UTC | #4
On Fri, Jan 15, 2016 at 11:20 PM, Javi Merino <javi.merino@arm.com> wrote:
> Eduardo, Rui,
>
> On Tue, Jan 05, 2016 at 07:19:25PM +0000, Javi Merino wrote:
>> On Mon, Dec 21, 2015 at 08:49:40AM +0530, Viresh Kumar wrote:
>> > On 19-12-15, 12:54, Javi Merino wrote:
>> > > 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 <drinkcat@chromium.org>
>> > > Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com>
>> > > Cc: Viresh Kumar <viresh.kumar@linaro.org>
>> > > Cc: Zhang Rui <rui.zhang@intel.com>
>> > > Cc: Eduardo Valentin <edubezval@gmail.com>
>> > > Signed-off-by: Javi Merino <javi.merino@arm.com>
>> > > ---
>> > >  drivers/thermal/cpu_cooling.c | 14 ++++++++------
>> > >  1 file changed, 8 insertions(+), 6 deletions(-)
>> >
>> > Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
>>
>> If there are no more objections, can you pick this up?
>
> Another gentle ping, can this be merged?

Tested-by: Nicolas Boichat <drinkcat@chromium.org>
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Javi Merino Jan. 25, 2016, 2:44 p.m. UTC | #5
On Mon, Jan 18, 2016 at 10:25:35AM +0800, Nicolas Boichat wrote:
> On Fri, Jan 15, 2016 at 11:20 PM, Javi Merino <javi.merino@arm.com> wrote:
> > Eduardo, Rui,
> >
> > On Tue, Jan 05, 2016 at 07:19:25PM +0000, Javi Merino wrote:
> >> On Mon, Dec 21, 2015 at 08:49:40AM +0530, Viresh Kumar wrote:
> >> > On 19-12-15, 12:54, Javi Merino wrote:
> >> > > 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 <drinkcat@chromium.org>
> >> > > Cc: Amit Daniel Kachhap <amit.kachhap@gmail.com>
> >> > > Cc: Viresh Kumar <viresh.kumar@linaro.org>
> >> > > Cc: Zhang Rui <rui.zhang@intel.com>
> >> > > Cc: Eduardo Valentin <edubezval@gmail.com>
> >> > > Signed-off-by: Javi Merino <javi.merino@arm.com>
> >> > > ---
> >> > >  drivers/thermal/cpu_cooling.c | 14 ++++++++------
> >> > >  1 file changed, 8 insertions(+), 6 deletions(-)
> >> >
> >> > Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> >>
> >> If there are no more objections, can you pick this up?
> >
> > Another gentle ping, can this be merged?
> 
> Tested-by: Nicolas Boichat <drinkcat@chromium.org>

Eduardo, Rui,

This has been in the list for more than a month now.  It fixes an out
of bounds access.  It has been acked by Viresh (comaintainer of
cpu_cooling) and has been tested by Nicolas.  Can you guys merge it
please?

Cheers,
Javi 
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diff mbox

Patch

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;