From: Heiner Kallweit <hkallweit1@gmail.com>
Date: Fri, 24 Nov 2017 06:47:50 +0000 (+0100)
Subject: eeprom: at24: check at24_read/write arguments
X-Git-Tag: v3.18.86~5
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=165a3c7d786e16dc4a84403b73d18dac9ea97f7d;p=thirdparty%2Fkernel%2Fstable.git

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 d87f77f790d67..c1cceeaf9aeb0 100644
--- 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.
@@ -328,6 +331,9 @@ 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);