From: Jonathan Cameron Date: Fri, 9 Sep 2011 08:53:05 +0000 (+0100) Subject: staging:iio:light: V3 fix out of bounds reg_cache[] access X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=25d7315a19bae4c880ca25b75fe8c632b79a21b7;p=linux-beck.git staging:iio:light: V3 fix out of bounds reg_cache[] access V3 is a straightforward forward port to teh current tree of V2. Simple fix is to just not cache REG_TEST (offset 8). Cache doesn't help REG_TEST anyway since we write all 8 bits exactly once (at resume/init time). Also fix an "off-by-one" allocation of reg_cache[] array size that was in the original code before I touched it. Reported-by: Dan Carpenter Signed-off-by: Grant Grundler Signed-off-by: Jonathan Cameron Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/iio/light/isl29018.c b/drivers/staging/iio/light/isl29018.c index f31e8c2fc5b6..3e9a06c20506 100644 --- a/drivers/staging/iio/light/isl29018.c +++ b/drivers/staging/iio/light/isl29018.c @@ -51,7 +51,7 @@ #define ISL29018_REG_ADD_DATA_LSB 0x02 #define ISL29018_REG_ADD_DATA_MSB 0x03 -#define ISL29018_MAX_REGS ISL29018_REG_ADD_DATA_MSB +#define ISL29018_MAX_REGS (ISL29018_REG_ADD_DATA_MSB+1) #define ISL29018_REG_TEST 0x08 #define ISL29018_TEST_SHIFT 0 @@ -70,22 +70,27 @@ struct isl29018_chip { static int isl29018_write_data(struct i2c_client *client, u8 reg, u8 val, u8 mask, u8 shift) { - u8 regval; - int ret = 0; + u8 regval = val; + int ret; struct isl29018_chip *chip = iio_priv(i2c_get_clientdata(client)); - regval = chip->reg_cache[reg]; - regval &= ~mask; - regval |= val << shift; + /* don't cache or mask REG_TEST */ + if (reg < ISL29018_MAX_REGS) { + regval = chip->reg_cache[reg]; + regval &= ~mask; + regval |= val << shift; + } ret = i2c_smbus_write_byte_data(client, reg, regval); if (ret) { dev_err(&client->dev, "Write to device fails status %x\n", ret); - return ret; + } else { + /* don't update cache on err */ + if (reg < ISL29018_MAX_REGS) + chip->reg_cache[reg] = regval; } - chip->reg_cache[reg] = regval; - return 0; + return ret; } static int isl29018_set_range(struct i2c_client *client, unsigned long range,