Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754521AbbFJP3k (ORCPT ); Wed, 10 Jun 2015 11:29:40 -0400 Received: from ip4-83-240-67-251.cust.nbox.cz ([83.240.67.251]:36104 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754283AbbFJP1q (ORCPT ); Wed, 10 Jun 2015 11:27:46 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Rusty Russell , Linus Torvalds , Jiri Slaby Subject: [PATCH 3.12 041/111] lguest: fix out-by-one error in address checking. Date: Wed, 10 Jun 2015 17:26:30 +0200 Message-Id: X-Mailer: git-send-email 2.4.2 In-Reply-To: <93091169a673f49c2574cddf1ef858cf0704f646.1433943052.git.jslaby@suse.cz> References: <93091169a673f49c2574cddf1ef858cf0704f646.1433943052.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1440 Lines: 41 From: Rusty Russell 3.12-stable 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: Jiri Slaby --- 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 0bf1e4edf04d..19da22249bd8 100644 --- a/drivers/lguest/core.c +++ b/drivers/lguest/core.c @@ -176,7 +176,7 @@ 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); } /* -- 2.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/