* [PATCH] thermal: intel_powerclamp: Check for a possible array out of bounds access.
@ 2023-06-02 8:55 Daniil Dulov
2023-06-04 16:13 ` Rafael J. Wysocki
0 siblings, 1 reply; 3+ messages in thread
From: Daniil Dulov @ 2023-06-02 8:55 UTC (permalink / raw)
To: Zhang Rui
Cc: Daniil Dulov, Daniel Lezcano, Amit Kucheria, Rafael J. Wysocki,
Srinivas Pandruvada, Greg Kroah-Hartman, Chen Yu, Sasha Levin,
Arjan van de Ven, Jacob Pan, linux-pm, linux-kernel, lvc-project
ratio may be equal to MAX_TARGET_RATIO - 1 that will result in
out of bound access.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Fixes: d6d71ee4a14a ("PM: Introduce Intel PowerClamp Driver")
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
---
drivers/thermal/intel/intel_powerclamp.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/thermal/intel/intel_powerclamp.c b/drivers/thermal/intel/intel_powerclamp.c
index fb04470d7d4b..9deaf2b8ccf6 100644
--- a/drivers/thermal/intel/intel_powerclamp.c
+++ b/drivers/thermal/intel/intel_powerclamp.c
@@ -277,7 +277,8 @@ static unsigned int get_compensation(int ratio)
comp = (cal_data[ratio].steady_comp +
cal_data[ratio - 1].steady_comp +
cal_data[ratio - 2].steady_comp) / 3;
- } else if (cal_data[ratio].confidence >= CONFIDENCE_OK &&
+ } else if (ratio < MAX_TARGET_RATIO - 1 &&
+ cal_data[ratio].confidence >= CONFIDENCE_OK &&
cal_data[ratio - 1].confidence >= CONFIDENCE_OK &&
cal_data[ratio + 1].confidence >= CONFIDENCE_OK) {
comp = (cal_data[ratio].steady_comp +
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] thermal: intel_powerclamp: Check for a possible array out of bounds access.
2023-06-02 8:55 [PATCH] thermal: intel_powerclamp: Check for a possible array out of bounds access Daniil Dulov
@ 2023-06-04 16:13 ` Rafael J. Wysocki
2023-06-05 16:36 ` srinivas pandruvada
0 siblings, 1 reply; 3+ messages in thread
From: Rafael J. Wysocki @ 2023-06-04 16:13 UTC (permalink / raw)
To: Daniil Dulov, Zhang Rui, Srinivas Pandruvada
Cc: Daniel Lezcano, Amit Kucheria, Chen Yu, Jacob Pan, linux-pm,
linux-kernel, lvc-project
Cc list trimmed.
On Fri, Jun 2, 2023 at 11:12 AM Daniil Dulov <d.dulov@aladdin.ru> wrote:
>
> ratio may be equal to MAX_TARGET_RATIO - 1 that will result in
> out of bound access.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: d6d71ee4a14a ("PM: Introduce Intel PowerClamp Driver")
> Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
> ---
> drivers/thermal/intel/intel_powerclamp.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/thermal/intel/intel_powerclamp.c b/drivers/thermal/intel/intel_powerclamp.c
> index fb04470d7d4b..9deaf2b8ccf6 100644
> --- a/drivers/thermal/intel/intel_powerclamp.c
> +++ b/drivers/thermal/intel/intel_powerclamp.c
> @@ -277,7 +277,8 @@ static unsigned int get_compensation(int ratio)
> comp = (cal_data[ratio].steady_comp +
> cal_data[ratio - 1].steady_comp +
> cal_data[ratio - 2].steady_comp) / 3;
> - } else if (cal_data[ratio].confidence >= CONFIDENCE_OK &&
> + } else if (ratio < MAX_TARGET_RATIO - 1 &&
> + cal_data[ratio].confidence >= CONFIDENCE_OK &&
> cal_data[ratio - 1].confidence >= CONFIDENCE_OK &&
> cal_data[ratio + 1].confidence >= CONFIDENCE_OK) {
> comp = (cal_data[ratio].steady_comp +
> --
Rui, Srinivas, can you have a look at this, please?
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] thermal: intel_powerclamp: Check for a possible array out of bounds access.
2023-06-04 16:13 ` Rafael J. Wysocki
@ 2023-06-05 16:36 ` srinivas pandruvada
0 siblings, 0 replies; 3+ messages in thread
From: srinivas pandruvada @ 2023-06-05 16:36 UTC (permalink / raw)
To: Rafael J. Wysocki, Daniil Dulov, Zhang Rui
Cc: Daniel Lezcano, Amit Kucheria, Chen Yu, Jacob Pan, linux-pm,
linux-kernel, lvc-project
On Sun, 2023-06-04 at 18:13 +0200, Rafael J. Wysocki wrote:
> Cc list trimmed.
>
> On Fri, Jun 2, 2023 at 11:12 AM Daniil Dulov <d.dulov@aladdin.ru>
> wrote:
> >
> > ratio may be equal to MAX_TARGET_RATIO - 1 that will result in
> > out of bound access.
> >
The description was not clear to me.
May be something like this:
"
The max value of "ratio" parameter passed to the function
get_compensation() is MAX_TARGET_RATIO - 1. The size of cal_data array
is MAX_TARGET_RATIO. Hence, accessing cal_data[ratio + 1], will result
in out of bound access.
Add a condition to check ratio < MAX_TARGET_RATIO - 1, before accsssing
cal_data[ratio + 1].
"
The change is correct. But for actual code change,
the ratio < MAX_TARGET_RATIO - 1 is also checked in else if() before,
which can be merged to check only once for this condition.
Thanks,
Srinivas
> > Found by Linux Verification Center (linuxtesting.org) with SVACE.
> >
> > Fixes: d6d71ee4a14a ("PM: Introduce Intel PowerClamp Driver")
> > Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
> > ---
> > drivers/thermal/intel/intel_powerclamp.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/thermal/intel/intel_powerclamp.c
> > b/drivers/thermal/intel/intel_powerclamp.c
> > index fb04470d7d4b..9deaf2b8ccf6 100644
> > --- a/drivers/thermal/intel/intel_powerclamp.c
> > +++ b/drivers/thermal/intel/intel_powerclamp.c
> > @@ -277,7 +277,8 @@ static unsigned int get_compensation(int ratio)
> > comp = (cal_data[ratio].steady_comp +
> > cal_data[ratio - 1].steady_comp +
> > cal_data[ratio - 2].steady_comp) / 3;
> > - } else if (cal_data[ratio].confidence >= CONFIDENCE_OK &&
I think the concern is that cal_data[ratio + 1] is going out of bound
for the "ratio" passed to this function, when ratio ==
ARRAY_SIZE(cal_data) - 1;
Here size of cal_data array is 50. The max possible "ratio" passed can
be 49.
> > + } else if (ratio < MAX_TARGET_RATIO - 1 &&
> > + cal_data[ratio].confidence >= CONFIDENCE_OK &&
> > cal_data[ratio - 1].confidence >= CONFIDENCE_OK &&
> > cal_data[ratio + 1].confidence >= CONFIDENCE_OK) {
> > comp = (cal_data[ratio].steady_comp +
> > --
>
> Rui, Srinivas, can you have a look at this, please?
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-06-05 16:37 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-06-02 8:55 [PATCH] thermal: intel_powerclamp: Check for a possible array out of bounds access Daniil Dulov
2023-06-04 16:13 ` Rafael J. Wysocki
2023-06-05 16:36 ` srinivas pandruvada
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).