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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 3ddd57a55acf8c79dff509079db1d9d5bf7ce66e..19c10dc5651327f3428582fd10bbbea767f589b6 100644 (file)
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -507,6 +507,9 @@ static int at24_read(void *priv, unsigned int off, void *val, size_t count)
        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.
@@ -539,6 +542,9 @@ static int at24_write(void *priv, unsigned int off, void *val, size_t count)
        if (unlikely(!count))
                return -EINVAL;
 
+       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.