Removes the risk of returning non-null terminated strings
to userspace in those cases the provided buffer is too small.
Signed-off-by: Magnus Vigerl?f <[email protected]>
---
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 12c7ab8..667333c 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -377,11 +377,13 @@ static int str_to_user(const char *str,
if (!str)
return -ENOENT;
- len = strlen(str) + 1;
- if (len > maxlen)
- len = maxlen;
+ len = strlen(str);
+ if (len >= maxlen)
+ len = maxlen - 1;
- return copy_to_user(p, str, len) ? -EFAULT : len;
+ if (copy_to_user(p, str, len))
+ return -EFAULT;
+ return put_user('\0', (char __user *)p + len) ? -EFAULT : len + 1;
}
static long evdev_ioctl_handler(struct file *file, unsigned int cmd,