From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.136]:53408 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752949AbbIOJLn (ORCPT ); Tue, 15 Sep 2015 05:11:43 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Rusty Russell , Linus Torvalds , Zefan Li Subject: [PATCH 3.4 113/146] lguest: fix out-by-one error in address checking. Date: Tue, 15 Sep 2015 17:03:48 +0800 Message-Id: <1442307861-32031-113-git-send-email-lizf@kernel.org> In-Reply-To: <1442307787-31952-1-git-send-email-lizf@kernel.org> References: <1442307787-31952-1-git-send-email-lizf@kernel.org> Sender: stable-owner@vger.kernel.org List-ID: From: Rusty Russell 3.4.109-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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 Signed-off-by: Linus Torvalds Signed-off-by: Zefan Li --- drivers/lguest/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/lguest/core.c b/drivers/lguest/core.c index b5fdcb7..34842e5 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -171,7 +171,7 @@ 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); } /* -- 1.9.1