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 5d7c0900fa1b129c8bf103d3eddd03cbd92fe80d..f112c5bc082a57b1c5402f1d2a21907f80b36637 100644 (file)
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -257,6 +257,9 @@ 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.
@@ -311,6 +314,9 @@ static ssize_t at24_eeprom_write(struct at24_data *at24, const char *buf,
        unsigned long timeout, write_time;
        unsigned next_page;
 
+       if (offset + count > at24->chip.byte_len)
+               return -EINVAL;
+
        /* Get corresponding I2C address and adjust offset */
        client = at24_translate_offset(at24, &offset);