[igt-dev] [PATCH i-g-t] tests/kms_plane_scaling: Fix out-of-bound array access

[igt-dev] [PATCH i-g-t] tests/kms_plane_scaling: Fix out-of-bound array access

[Swati Sharma]

When k == n_planes - 1, we will try to access planes[n_planes],
which is out of bounds. Fix this.

Reported-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
---
 tests/kms_plane_scaling.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/kms_plane_scaling.c b/tests/kms_plane_scaling.c
index 3a6904afb..8d78752cc 100644
--- a/tests/kms_plane_scaling.c
+++ b/tests/kms_plane_scaling.c
@@ -744,7 +744,7 @@ test_planes_scaling_combo(data_t *d, int w1, int h1, int w2, int h2,
 		igt_assert(0);
 	}
 
-	for (int k = 0; k < display->pipes[pipe].n_planes; k++) {
+	for (int k = 0; k < display->pipes[pipe].n_planes - 1; k++) {
 		igt_plane_t *p1, *p2;
 
 		p1 = &display->pipes[pipe].planes[k];
-- 
2.25.1

[igt-dev] [PATCH i-g-t] tests/kms_plane_scaling: Fix out-of-bound array access

[Swati Sharma]

With this fix we are solving 2 issues. Firstly, the
planes_scaling_combo() tests were leaving one scaler assigned
after running sub-test with two consecutive planes because
one scaler was getting reused in the next run.

Secondly, when k == n_planes - 1, we were trying to access
planes[n_planes], which led to array out of bounds error.

Suggested-by: Luca Coelho <luciano.coelho@intel.com>
Suggested-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
Reported-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
---
 tests/kms_plane_scaling.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/kms_plane_scaling.c b/tests/kms_plane_scaling.c
index 3a6904afb..3898446ed 100644
--- a/tests/kms_plane_scaling.c
+++ b/tests/kms_plane_scaling.c
@@ -744,7 +744,7 @@ test_planes_scaling_combo(data_t *d, int w1, int h1, int w2, int h2,
 		igt_assert(0);
 	}
 
-	for (int k = 0; k < display->pipes[pipe].n_planes; k++) {
+	for (int k = 0; k < display->pipes[pipe].n_planes; k += 2) {
 		igt_plane_t *p1, *p2;
 
 		p1 = &display->pipes[pipe].planes[k];
-- 
2.25.1

Re: [igt-dev] [PATCH i-g-t] tests/kms_plane_scaling: Fix out-of-bound array access

[Coelho, Luciano]

On Thu, 2023-03-16 at 21:43 +0530, Swati Sharma wrote:
> With this fix we are solving 2 issues. Firstly, the
> planes_scaling_combo() tests were leaving one scaler assigned
> after running sub-test with two consecutive planes because
> one scaler was getting reused in the next run.
> 
> Secondly, when k == n_planes - 1, we were trying to access
> planes[n_planes], which led to array out of bounds error.
> 
> Suggested-by: Luca Coelho <luciano.coelho@intel.com>
> Suggested-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
> Reported-by: Luca Coelho <luciano.coelho@intel.com>
> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> ---

Looks goods.  Thanks for fixing it.

Reviewed-by: Luca Coelho <luciano.coelho@intel.com>

--
Cheers,
Luca.

Re: [igt-dev] [PATCH i-g-t] tests/kms_plane_scaling: Fix out-of-bound array access

[Juha-Pekka Heikkilä]

Hi Swati,

Swati Sharma kirjoitti 16.3.2023 klo 18.13:
> With this fix we are solving 2 issues. Firstly, the
> planes_scaling_combo() tests were leaving one scaler assigned
> after running sub-test with two consecutive planes because
> one scaler was getting reused in the next run.
> 
> Secondly, when k == n_planes - 1, we were trying to access
> planes[n_planes], which led to array out of bounds error.
> 
> Suggested-by: Luca Coelho <luciano.coelho@intel.com>
> Suggested-by: Juha-Pekka Heikkila <juhapekka.heikkila@gmail.com>
> Reported-by: Luca Coelho <luciano.coelho@intel.com>
> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> ---
>   tests/kms_plane_scaling.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tests/kms_plane_scaling.c b/tests/kms_plane_scaling.c
> index 3a6904afb..3898446ed 100644
> --- a/tests/kms_plane_scaling.c
> +++ b/tests/kms_plane_scaling.c
> @@ -744,7 +744,7 @@ test_planes_scaling_combo(data_t *d, int w1, int h1, int w2, int h2,
>   		igt_assert(0);
>   	}
>   
> -	for (int k = 0; k < display->pipes[pipe].n_planes; k++) {
> +	for (int k = 0; k < display->pipes[pipe].n_planes; k += 2) {

What happen if n_planes is not even number? Is that reasonable 
expectation to happen here?

>   		igt_plane_t *p1, *p2;
>   
>   		p1 = &display->pipes[pipe].planes[k];

[igt-dev] [PATCH i-g-t] tests/kms_plane_scaling: Fix out-of-bound array access

[Swati Sharma]

When k == n_planes - 1, we will try to access planes[n_planes],
which is out of bounds. Fix this.

Reported-by: Coelho, Luciano <luciano.coelho@intel.com>
Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
---
 tests/kms_plane_scaling.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/kms_plane_scaling.c b/tests/kms_plane_scaling.c
index 3a6904af..8d78752c 100644
--- a/tests/kms_plane_scaling.c
+++ b/tests/kms_plane_scaling.c
@@ -744,7 +744,7 @@ test_planes_scaling_combo(data_t *d, int w1, int h1, int w2, int h2,
 		igt_assert(0);
 	}
 
-	for (int k = 0; k < display->pipes[pipe].n_planes; k++) {
+	for (int k = 0; k < display->pipes[pipe].n_planes - 1; k++) {
 		igt_plane_t *p1, *p2;
 
 		p1 = &display->pipes[pipe].planes[k];
-- 
2.25.1