[PATCH 3.2 020/140] eeprom: at24: check at24_read/write arguments

Ben Hutchings
2018-02-28T16:33:16Z

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: Ben Hutchings <ben@decadent.org.uk>
---
drivers/misc/eeprom/at24.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -274,6 +274,9 @@ 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.
@@ -396,6 +399,9 @@ static ssize_t at24_write(struct at24_da
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.