On Wed, 14 Sep 2022, cy_huang wrote:

From: ChiYuan Huang cy_huang@richtek.com

Fix the potential risk for null pointer if bank index is over the maximimum.

Refer to the discussion list for the experiment result on mt6370. https://lore.kernel.org/all/20220914013345.GA5802@cyhuang-hp-elitebook-840-g... If not to check the bound, there is the same issue on mt6360.

Fixes: 3b0850440a06c (mfd: mt6360: Merge different sub-devices I2C read/write) Cc: stable@vger.kernel.org Signed-off-by: ChiYuan Huang cy_huang@richtek.com

---

drivers/mfd/mt6360-core.c | 6 ++++++ 1 file changed, 6 insertions(+)

diff --git a/drivers/mfd/mt6360-core.c b/drivers/mfd/mt6360-core.c index 6eaa677..d375333 100644 --- a/drivers/mfd/mt6360-core.c +++ b/drivers/mfd/mt6360-core.c @@ -410,6 +410,9 @@ static int mt6360_regmap_read(void *context, const void *reg, size_t reg_size, u8 crc; int ret;

• if (bank >= MT6360_SLAVE_MAX)

• return -EINVAL;
  

It's too late to check bank's value here, we have already used it to index into an array by this point. Please fix that.

if (bank == MT6360_SLAVE_PMIC || bank == MT6360_SLAVE_LDO) { crc_needed = true; ret = mt6360_xlate_pmicldo_addr(&reg_addr, val_size); @@ -460,6 +463,9 @@ static int mt6360_regmap_write(void *context, const void *val, size_t val_size) int write_size = val_size - MT6360_REGMAP_REG_BYTE_SIZE; int ret;

• if (bank >= MT6360_SLAVE_MAX)

• return -EINVAL;
  

• if (bank == MT6360_SLAVE_PMIC || bank == MT6360_SLAVE_LDO) { crc_needed = true; ret = mt6360_xlate_pmicldo_addr(&reg_addr, val_size - MT6360_REGMAP_REG_BYTE_SIZE);