Commit 5f4f94e9 authored by ChiYuan Huang's avatar ChiYuan Huang Committed by Lee Jones
Browse files

mfd: mt6360: Add bounds checking in Regmap read/write call-backs 

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@cyhuang-hp-elitebook-840-g3.rt/


If not to check the bound, there is the same issue on mt6360.

Cc: stable@vger.kernel.org
Fixes: 3b085044 (mfd: mt6360: Merge different sub-devices I2C read/write)
Signed-off-by: default avatarChiYuan Huang <cy_huang@richtek.com>
Signed-off-by: default avatarLee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/1664416817-31590-1-git-send-email-u0084500@gmail.com
parent 4bef4d51

drivers/mfd/mt6360-core.c

+12 −2
Original line number Diff line number Diff line
@@ -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);