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>

diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 5d4fd69..94b8a33 100644 (file)
--- 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);
 }