From: ChiYuan Huang <cy_huang@xxxxxxxxxxx> commit 5f4f94e9f26cca6514474b307b59348b8485e711 upstream. Fix the potential risk of OOB read 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@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ If not to check the bound, there is the same issue on mt6360. Cc: stable@xxxxxxxxxxxxxxx Fixes: 3b0850440a06c (mfd: mt6360: Merge different sub-devices I2C read/write) Signed-off-by: ChiYuan Huang <cy_huang@xxxxxxxxxxx> Signed-off-by: Lee Jones <lee@xxxxxxxxxx> Link: https://lore.kernel.org/r/1664416817-31590-1-git-send-email-u0084500@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mfd/mt6360-core.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) --- a/drivers/mfd/mt6360-core.c +++ b/drivers/mfd/mt6360-core.c @@ -402,7 +402,7 @@ static int mt6360_regmap_read(void *cont 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 *cont 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(®_addr, val_size); @@ -453,13 +458,18 @@ static int mt6360_regmap_write(void *con 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(®_addr, val_size - MT6360_REGMAP_REG_BYTE_SIZE);
