Patch "lguest: fix out-by-one error in address checking." has been added to the 4.0-stable tree

Patch "lguest: fix out-by-one error in address checking." has been added to the 4.0-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    lguest: fix out-by-one error in address checking.

to the 4.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     lguest-fix-out-by-one-error-in-address-checking.patch
and it can be found in the queue-4.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 83a35114d0e4583e6b0ca39502e68b6a92e2910c Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Wed, 27 May 2015 10:59:26 +0930
Subject: lguest: fix out-by-one error in address checking.

From: Rusty Russell <rusty@rustcorp.com.au>

commit 83a35114d0e4583e6b0ca39502e68b6a92e2910c upstream.

This bug has been there since day 1; addresses in the top guest physical
page weren't considered valid.  You could map that page (the check in
check_gpte() is correct), but if a guest tried to put a pagetable there
we'd check that address manually when walking it, and kill the guest.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/lguest/core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/lguest/core.c
+++ b/drivers/lguest/core.c
@@ -173,7 +173,7 @@ static void unmap_switcher(void)
 bool lguest_address_ok(const struct lguest *lg,
 		       unsigned long addr, unsigned long len)
 {
-	return (addr+len) / PAGE_SIZE < lg->pfn_limit && (addr+len >= addr);
+	return addr+len <= lg->pfn_limit * PAGE_SIZE && (addr+len >= addr);
 }
 
 /*


Patches currently in stable-queue which might be from rusty@rustcorp.com.au are

queue-4.0/lguest-fix-out-by-one-error-in-address-checking.patch