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mfd: mt6360: add bound check in regmap read/write function

PATCH Applied cy_huang 2 participants 3 messages Sep 29, 2022 – Oct 31, 2022

Subsystems (3)
Stable branch Arm MediaTek Multifunction devices (MFD)

v2 of 3 Applied Latest is v3 →

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cy_huang

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#0 lore raw

PATCH v2 1/1 mfd: mt6360: add bound check in regmap read/write function

From: ChiYuan Huang <[email protected]>

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/[email protected]/
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 [email protected]
Signed-off-by ChiYuan Huang <[email protected]>

---
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(-)
drivers/mfd/mt6360-core.c +12 -2
index 6eaa677..d3b32eb 100644
@@ -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);
Signature · 1 line
2.7.4
author
#1 lore raw

Hi,

cy_huang <[email protected]> 於 2022年9月29日 週四 上午10:00寫道：

Quoted 12 lines

From: ChiYuan Huang <[email protected]>

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/[email protected]/
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 [email protected]
Signed-off-by ChiYuan Huang <[email protected]>
Quoted 8 lines

---
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?

Quoted 48 lines
drivers/mfd/mt6360-core.c +12 -3
index 6eaa677..d3b32eb 100644
@@ -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

maintainer Applied
#2 lore raw
In reply to cy_huang
Quoted 11 lines · cy_huang

From: ChiYuan Huang <[email protected]>

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/[email protected]/
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 [email protected]
Signed-off-by ChiYuan Huang <[email protected]>
Quoted 7 lines

---
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(-)

Applied, thanks.

Signature · 1 line
Lee Jones [李琼斯]