[PATCH 4.4 16/27] eeprom: at24: check at24_read/write arguments

Greg Kroah-Hartman
2017-12-04T16:39:33Z

From: Heiner Kallweit <hkallweit1@gmail.com>

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>

---
drivers/misc/eeprom/at24.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -257,6 +257,9 @@ static ssize_t at24_read(struct at24_dat
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
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);