Hi,

cy_huang u0084500@gmail.com 於 2022年9月29日 週四 上午10:00寫道：

From: ChiYuan Huang cy_huang@richtek.com

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

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

---

Since v2:

• Assign i2c bank variable after bank index is already checked.

---

drivers/mfd/mt6360-core.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)

Any comment?

diff --git a/drivers/mfd/mt6360-core.c b/drivers/mfd/mt6360-core.c index 6eaa677..d3b32eb 100644 --- a/drivers/mfd/mt6360-core.c +++ b/drivers/mfd/mt6360-core.c @@ -402,7 +402,7 @@ static int mt6360_regmap_read(void *context, const void *reg, size_t reg_size, struct mt6360_ddata *ddata = context; u8 bank = *(u8 *)reg; u8 reg_addr = *(u8 *)(reg + 1);

•   struct i2c_client *i2c = ddata->i2c[bank];
  

•   struct i2c_client *i2c;
    bool crc_needed = false;
    u8 *buf;
    int buf_len = MT6360_ALLOC_READ_SIZE(val_size);
  

@@ -410,6 +410,11 @@ 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;
  

•   i2c = ddata->i2c[bank];
  

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

@@ -453,13 +458,18 @@ static int mt6360_regmap_write(void *context, const void *val, size_t val_size) struct mt6360_ddata *ddata = context; u8 bank = *(u8 *)val; u8 reg_addr = *(u8 *)(val + 1);

•   struct i2c_client *i2c = ddata->i2c[bank];
  

•   struct i2c_client *i2c;
    bool crc_needed = false;
    u8 *buf;
    int buf_len = MT6360_ALLOC_WRITE_SIZE(val_size);
    int write_size = val_size - MT6360_REGMAP_REG_BYTE_SIZE;
    int ret;
  
  

•   if (bank >= MT6360_SLAVE_MAX)
  

•           return -EINVAL;
  

•   i2c = ddata->i2c[bank];
  

•   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);
  

-- 2.7.4