diff mbox series

thermal: cpufreq_cooling: fix slab OOB issue

Message ID 20201223074849.1989-1-michael.kao@mediatek.com
State Superseded
Headers show
Series thermal: cpufreq_cooling: fix slab OOB issue | expand

Commit Message

Michael Kao Dec. 23, 2020, 7:48 a.m. UTC
From: brian-sy yang <brian-sy.yang@mediatek.com>

Slab OOB issue is scanned by KASAN in cpu_power_to_freq().
If power is limited below the power of OPP0 in EM table,
it will cause slab out-of-bound issue with negative array
index.

Return the lowest frequency if limited power cannot found
a suitable OPP in EM table to fix this issue.

Backtrace:
[<ffffffd02d2a37f0>] die+0x104/0x5ac
[<ffffffd02d2a5630>] bug_handler+0x64/0xd0
[<ffffffd02d288ce4>] brk_handler+0x160/0x258
[<ffffffd02d281e5c>] do_debug_exception+0x248/0x3f0
[<ffffffd02d284488>] el1_dbg+0x14/0xbc
[<ffffffd02d75d1d4>] __kasan_report+0x1dc/0x1e0
[<ffffffd02d75c2e0>] kasan_report+0x10/0x20
[<ffffffd02d75def8>] __asan_report_load8_noabort+0x18/0x28
[<ffffffd02e6fce5c>] cpufreq_power2state+0x180/0x43c
[<ffffffd02e6ead80>] power_actor_set_power+0x114/0x1d4
[<ffffffd02e6fac24>] allocate_power+0xaec/0xde0
[<ffffffd02e6f9f80>] power_allocator_throttle+0x3ec/0x5a4
[<ffffffd02e6ea888>] handle_thermal_trip+0x160/0x294
[<ffffffd02e6edd08>] thermal_zone_device_check+0xe4/0x154
[<ffffffd02d351cb4>] process_one_work+0x5e4/0xe28
[<ffffffd02d352f44>] worker_thread+0xa4c/0xfac
[<ffffffd02d360124>] kthread+0x33c/0x358
[<ffffffd02d289940>] ret_from_fork+0xc/0x18

Signed-off-by: brian-sy yang <brian-sy.yang@mediatek.com>
---
 drivers/thermal/cpufreq_cooling.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Lukasz Luba Dec. 28, 2020, 10:28 a.m. UTC | #1
On 12/23/20 7:48 AM, Michael Kao wrote:
> From: brian-sy yang <brian-sy.yang@mediatek.com>

> 

> Slab OOB issue is scanned by KASAN in cpu_power_to_freq().

> If power is limited below the power of OPP0 in EM table,

> it will cause slab out-of-bound issue with negative array

> index.

> 

> Return the lowest frequency if limited power cannot found

> a suitable OPP in EM table to fix this issue.

> 

> Backtrace:

> [<ffffffd02d2a37f0>] die+0x104/0x5ac

> [<ffffffd02d2a5630>] bug_handler+0x64/0xd0

> [<ffffffd02d288ce4>] brk_handler+0x160/0x258

> [<ffffffd02d281e5c>] do_debug_exception+0x248/0x3f0

> [<ffffffd02d284488>] el1_dbg+0x14/0xbc

> [<ffffffd02d75d1d4>] __kasan_report+0x1dc/0x1e0

> [<ffffffd02d75c2e0>] kasan_report+0x10/0x20

> [<ffffffd02d75def8>] __asan_report_load8_noabort+0x18/0x28

> [<ffffffd02e6fce5c>] cpufreq_power2state+0x180/0x43c

> [<ffffffd02e6ead80>] power_actor_set_power+0x114/0x1d4

> [<ffffffd02e6fac24>] allocate_power+0xaec/0xde0

> [<ffffffd02e6f9f80>] power_allocator_throttle+0x3ec/0x5a4

> [<ffffffd02e6ea888>] handle_thermal_trip+0x160/0x294

> [<ffffffd02e6edd08>] thermal_zone_device_check+0xe4/0x154

> [<ffffffd02d351cb4>] process_one_work+0x5e4/0xe28

> [<ffffffd02d352f44>] worker_thread+0xa4c/0xfac

> [<ffffffd02d360124>] kthread+0x33c/0x358

> [<ffffffd02d289940>] ret_from_fork+0xc/0x18


Thank you for looking at this and sending a fix.

It's worth to add the 'fixes' line:

Fixes: 371a3bc79c11b ("thermal/drivers/cpufreq_cooling: Fix wrong 
frequency converted from power")

IIRC that patch was sent to stable trees. Might be worth to check
and apply this fix.


> 

> Signed-off-by: brian-sy yang <brian-sy.yang@mediatek.com>



Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>



> ---

>   drivers/thermal/cpufreq_cooling.c | 2 +-

>   1 file changed, 1 insertion(+), 1 deletion(-)

> 

> diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c

> index cc2959f22f01..fb33b3480a8f 100644

> --- a/drivers/thermal/cpufreq_cooling.c

> +++ b/drivers/thermal/cpufreq_cooling.c

> @@ -123,7 +123,7 @@ static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev,

>   {

>   	int i;

>   

> -	for (i = cpufreq_cdev->max_level; i >= 0; i--) {

> +	for (i = cpufreq_cdev->max_level; i > 0; i--) {

>   		if (power >= cpufreq_cdev->em->table[i].power)

>   			break;

>   	}

>
diff mbox series

Patch

diff --git a/drivers/thermal/cpufreq_cooling.c b/drivers/thermal/cpufreq_cooling.c
index cc2959f22f01..fb33b3480a8f 100644
--- a/drivers/thermal/cpufreq_cooling.c
+++ b/drivers/thermal/cpufreq_cooling.c
@@ -123,7 +123,7 @@  static u32 cpu_power_to_freq(struct cpufreq_cooling_device *cpufreq_cdev,
 {
 	int i;
 
-	for (i = cpufreq_cdev->max_level; i >= 0; i--) {
+	for (i = cpufreq_cdev->max_level; i > 0; i--) {
 		if (power >= cpufreq_cdev->em->table[i].power)
 			break;
 	}