misc/at24: avoid infinite loop on write()

This change fixes a problem of infinite zero byte write() without
an error status, if there is an attempt to write a file bigger than
EEPROM size over sysfs interface.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 5d4fd69d04ca..94b8a3324319 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -428,6 +428,9 @@ static ssize_t at24_bin_write(struct file *filp, struct kobject *kobj,
 {
         struct at24_data *at24;
 
+        if (unlikely(off >= attr->size))
+                return -EFBIG;
+
         at24 = dev_get_drvdata(container_of(kobj, struct device, kobj));
         return at24_write(at24, buf, off, count);
 }