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: 3b0850440a (mfd: mt6360: Merge different sub-devices I2C read/write)
Signed-off-by: ChiYuan Huang <cy_huang@richtek.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/1664416817-31590-1-git-send-email-u0084500@gmail.com
This commit is contained in:
ChiYuan Huang 2022-09-29 10:00:17 +08:00 committed by Lee Jones
parent 4bef4d519b
commit 5f4f94e9f2

View File

@ -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);