diff mbox series

[v2] thermal: cpufreq_cooling: fix slab OOB issue

Message ID 20201229050831.19493-1-michael.kao@mediatek.com
State New
Headers show
Series [v2] thermal: cpufreq_cooling: fix slab OOB issue | expand

Commit Message

Michael Kao Dec. 29, 2020, 5:08 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

Fixes: 371a3bc79c11b ("thermal/drivers/cpufreq_cooling: Fix wrong frequency converted from power")
Signed-off-by: brian-sy yang <brian-sy.yang@mediatek.com>
Signed-off-by: Michael Kao <michael.kao@mediatek.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
---

Changes from v1:
- add fixes tag
- add reviewed-by

 drivers/thermal/cpufreq_cooling.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Michael Kao March 30, 2021, 2:51 a.m. UTC | #1
Dear Daniel,

Kindly ping.
Can this patch be merged? Or any comment?

BR,
Michael

On Tue, 2020-12-29 at 13:08 +0800, 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

> 

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

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

> Signed-off-by: Michael Kao <michael.kao@mediatek.com>

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

> ---

> 

> Changes from v1:

> - add fixes tag

> - add reviewed-by

> 

>  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;

>  	}
Lukasz Luba March 30, 2021, 8:42 a.m. UTC | #2
On 3/30/21 3:51 AM, Michael Kao wrote:
> Dear Daniel,
> 
> Kindly ping.
> Can this patch be merged? Or any comment?
> 
> BR,
> Michael
> 
> On Tue, 2020-12-29 at 13:08 +0800, Michael Kao wrote:

Please also send it to stable@vger.kernel.org
since it affects stable versions starting from v5.7.
Was applied there as  9006b543384ab10 [1].

Regards,
Lukasz

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.7.8
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;
 	}