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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, "Eric W. Biederman" <ebiederm@xmission.com>
Subject: [PATCH 3.18 20/29] userns; Correct the comment in map_write
Date:   Fri,  7 Sep 2018 23:10:41 +0200
Message-Id: <20180907210910.914702875@linuxfoundation.org>
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3.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Eric W. Biederman <ebiederm@xmission.com>

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>

---
 kernel/user_namespace.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -643,7 +643,7 @@ static ssize_t map_write(struct file *fi
 	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;