[PATCH AUTOSEL 6.1 07/61] drm/amd/display: Check gpio_id before used as array index

Sasha Levin
2024-08-01T00:28:34Z

From: Alex Hung <alex.hung@amd.com>

[ Upstream commit 2a5626eeb3b5eec7a36886f9556113dd93ec8ed6 ]

[WHY & HOW]
GPIO_ID_UNKNOWN (-1) is not a valid value for array index and therefore
should be checked in advance.

This fixes 5 OVERRUN issues reported by Coverity.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Alex Hung <alex.hung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c b/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c
index 3ede6e02c3a78..2f8ca831afa2b 100644
--- a/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c
+++ b/drivers/gpu/drm/amd/display/dc/gpio/gpio_service.c
@@ -239,6 +239,9 @@ static bool is_pin_busy(
enum gpio_id id,
uint32_t en)
{
+ if (id == GPIO_ID_UNKNOWN)
+ return false;
+
return service->busyness[id][en];
}

@@ -247,6 +250,9 @@ static void set_pin_busy(
enum gpio_id id,
uint32_t en)
{
+ if (id == GPIO_ID_UNKNOWN)
+ return;
+
service->busyness[id][en] = true;
}

@@ -255,6 +261,9 @@ static void set_pin_free(
enum gpio_id id,
uint32_t en)
{
+ if (id == GPIO_ID_UNKNOWN)
+ return;
+
service->busyness[id][en] = false;
}

@@ -263,7 +272,7 @@ enum gpio_result dal_gpio_service_lock(
enum gpio_id id,
uint32_t en)
{
- if (!service->busyness[id]) {
+ if (id != GPIO_ID_UNKNOWN && !service->busyness[id]) {
ASSERT_CRITICAL(false);
return GPIO_RESULT_OPEN_FAILED;
}
@@ -277,7 +286,7 @@ enum gpio_result dal_gpio_service_unlock(
enum gpio_id id,
uint32_t en)
{
- if (!service->busyness[id]) {
+ if (id != GPIO_ID_UNKNOWN && !service->busyness[id]) {
ASSERT_CRITICAL(false);
return GPIO_RESULT_OPEN_FAILED;
}
--
2.43.0