userns; Correct the comment in map_write

commit 36476beac4f8ca9dc7722790b2e8ef0e8e51034e upstream.

It is important that all maps are less than PAGE_SIZE
or else setting the last byte of the buffer to '0'
could write off the end of the allocated storage.

Correct the misleading comment.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index a2e37c5d2f63035d4cee00bb12a565f9bf8be774..ad419b04c1469c1be9731cb4cbaf4b7dd02238e1 100644 (file)
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -643,7 +643,7 @@ static ssize_t map_write(struct file *file, const char __user *buf,
        if (!page)
                goto out;
 
-       /* Only allow <= page size writes at the beginning of the file */
+       /* Only allow < page size writes at the beginning of the file */
        ret = -EINVAL;
        if ((*ppos != 0) || (count >= PAGE_SIZE))
                goto out;