Re: [PATCH v2] mfd: mt6360: add bound check in regmap read/write function
From: ChiYuan Huang <hidden>
Date: 2022-10-20 07:46:37
Also in:
linux-mediatek, lkml, stable
Hi, cy_huang [off-list ref] 於 2022年9月29日 週四 上午10:00寫道：
From: ChiYuan Huang <redacted> 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-g3.rt/ (local) 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 <redacted> --- 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 hunk ↗ jump to hunk
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(®_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(®_addr, val_size - MT6360_REGMAP_REG_BYTE_SIZE); --2.7.4
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