eeprom: at24: check at24_read/write arguments

commit d9bcd462daf34aebb8de9ad7f76de0198bb5a0f0 upstream.

So far we completely rely on the caller to provide valid arguments.
To be on the safe side perform an own sanity check.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index ab1ad41..18b2dec 100644 (file)
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -274,6 +274,9 @@ static ssize_t at24_read(struct at24_data *at24,
        if (unlikely(!count))
                return count;
 
+       if (off + count > at24->chip.byte_len)
+               return -EINVAL;
+
        /*
         * Read data from chip, protecting against concurrent updates
         * from this host, but not from other I2C masters.
@@ -396,6 +399,9 @@ static ssize_t at24_write(struct at24_data *at24, const char *buf, loff_t off,
        if (unlikely(!count))
                return count;
 
+       if (off + count > at24->chip.byte_len)
+               return -EINVAL;
+
        /*
         * Write data to chip, protecting against concurrent updates
         * from this host, but not from other I2C masters.