[PATCH AUTOSEL 6.1 35/58] regulator: max77802: Bounds check regulator id against opmode

Sasha Levin
2023-02-27T02:11:13Z

From: Kees Cook <keescook@chromium.org>

[ Upstream commit 4fd8bcec5fd7c0d586206fa2f42bd67b06cdaa7e ]

Explicitly bounds-check the id before accessing the opmode array. Seen
with GCC 13:

../drivers/regulator/max77802-regulator.c: In function 'max77802_enable':
../drivers/regulator/max77802-regulator.c:217:29: warning: array subscript [0, 41] is outside array bounds of 'unsigned int[42]' [-Warray-bounds=]
217 | if (max77802->opmode[id] == MAX77802_OFF_PWRREQ)
| ~~~~~~~~~~~~~~~~^~~~
../drivers/regulator/max77802-regulator.c:62:22: note: while referencing 'opmode'
62 | unsigned int opmode[MAX77802_REG_MAX];
| ^~~~~~

Cc: Javier Martinez Canillas <javier@dowhile0.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20230127225203.never.864-kees@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/regulator/max77802-regulator.c | 34 ++++++++++++++++++--------
1 file changed, 24 insertions(+), 10 deletions(-)

diff --git a/drivers/regulator/max77802-regulator.c b/drivers/regulator/max77802-regulator.c
index 21e0eb0f43f94..befe5f319819b 100644
--- a/drivers/regulator/max77802-regulator.c
+++ b/drivers/regulator/max77802-regulator.c
@@ -94,9 +94,11 @@ static int max77802_set_suspend_disable(struct regulator_dev *rdev)
{
unsigned int val = MAX77802_OFF_PWRREQ;
struct max77802_regulator_prv *max77802 = rdev_get_drvdata(rdev);
- int id = rdev_get_id(rdev);
+ unsigned int id = rdev_get_id(rdev);
int shift = max77802_get_opmode_shift(id);

+ if (WARN_ON_ONCE(id >= ARRAY_SIZE(max77802->opmode)))
+ return -EINVAL;
max77802->opmode[id] = val;
return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
rdev->desc->enable_mask, val << shift);
@@ -110,7 +112,7 @@ static int max77802_set_suspend_disable(struct regulator_dev *rdev)
static int max77802_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
struct max77802_regulator_prv *max77802 = rdev_get_drvdata(rdev);
- int id = rdev_get_id(rdev);
+ unsigned int id = rdev_get_id(rdev);
unsigned int val;
int shift = max77802_get_opmode_shift(id);

@@ -127,6 +129,9 @@ static int max77802_set_mode(struct regulator_dev *rdev, unsigned int mode)
return -EINVAL;
}

+ if (WARN_ON_ONCE(id >= ARRAY_SIZE(max77802->opmode)))
+ return -EINVAL;
+
max77802->opmode[id] = val;
return regmap_update_bits(rdev->regmap, rdev->desc->enable_reg,
rdev->desc->enable_mask, val << shift);
@@ -135,8 +140,10 @@ static int max77802_set_mode(struct regulator_dev *rdev, unsigned int mode)
static unsigned max77802_get_mode(struct regulator_dev *rdev)
{
struct max77802_regulator_prv *max77802 = rdev_get_drvdata(rdev);
- int id = rdev_get_id(rdev);
+ unsigned int id = rdev_get_id(rdev);

+ if (WARN_ON_ONCE(id >= ARRAY_SIZE(max77802->opmode)))
+ return -EINVAL;
return max77802_map_mode(max77802->opmode[id]);
}

@@ -160,10 +167,13 @@ static int max77802_set_suspend_mode(struct regulator_dev *rdev,
unsigned int mode)
{
struct max77802_regulator_prv *max77802 = rdev_get_drvdata(rdev);
- int id = rdev_get_id(rdev);
+ unsigned int id = rdev_get_id(rdev);
unsigned int val;
int shift = max77802_get_opmode_shift(id);

+ if (WARN_ON_ONCE(id >= ARRAY_SIZE(max77802->opmode)))
+ return -EINVAL;
+
/*
* If the regulator has been disabled for suspend
* then is invalid to try setting a suspend mode.
@@ -209,9 +219,11 @@ static int max77802_set_suspend_mode(struct regulator_dev *rdev,
static int max77802_enable(struct regulator_dev *rdev)
{
struct max77802_regulator_prv *max77802 = rdev_get_drvdata(rdev);
- int id = rdev_get_id(rdev);
+ unsigned int id = rdev_get_id(rdev);
int shift = max77802_get_opmode_shift(id);

+ if (WARN_ON_ONCE(id >= ARRAY_SIZE(max77802->opmode)))
+ return -EINVAL;
if (max77802->opmode[id] == MAX77802_OFF_PWRREQ)
max77802->opmode[id] = MAX77802_OPMODE_NORMAL;

@@ -495,7 +507,7 @@ static int max77802_pmic_probe(struct platform_device *pdev)

for (i = 0; i < MAX77802_REG_MAX; i++) {
struct regulator_dev *rdev;
- int id = regulators[i].id;
+ unsigned int id = regulators[i].id;
int shift = max77802_get_opmode_shift(id);
int ret;

@@ -513,10 +525,12 @@ static int max77802_pmic_probe(struct platform_device *pdev)
* the hardware reports OFF as the regulator operating mode.
* Default to operating mode NORMAL in that case.
*/
- if (val == MAX77802_STATUS_OFF)
- max77802->opmode[id] = MAX77802_OPMODE_NORMAL;
- else
- max77802->opmode[id] = val;
+ if (id < ARRAY_SIZE(max77802->opmode)) {
+ if (val == MAX77802_STATUS_OFF)
+ max77802->opmode[id] = MAX77802_OPMODE_NORMAL;
+ else
+ max77802->opmode[id] = val;
+ }

rdev = devm_regulator_register(&pdev->dev,
&regulators[i], &config);
--
2.39.0