From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6EFD1C3A5A1 for ; Thu, 22 Aug 2019 17:18:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 401B52089E for ; Thu, 22 Aug 2019 17:18:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494285; bh=VsA1tRE7LS3MYwuj23vcDHayJKy/yZnl8/Iot3W2XJk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fSe371wtzfMKkxOE/EcLn91ESwYEmpkaU7tj9Cx6qOa4qdvy2nKZEtaKK3ginM6nR 1/VrufME9NeMnEadrXVE0lyQbvXSfpLPYBKhUoju8SrJNa4xhzVd3aYCHW5kLV91fA xN6YgD21FVTsjfa4dKNTqv+DeAlTZA+sGdWOI3U8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391520AbfHVRSE (ORCPT ); Thu, 22 Aug 2019 13:18:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:57750 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390269AbfHVRIU (ORCPT ); Thu, 22 Aug 2019 13:08:20 -0400 Received: from sasha-vm.mshome.net (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D89F823404; Thu, 22 Aug 2019 17:08:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566493700; bh=VsA1tRE7LS3MYwuj23vcDHayJKy/yZnl8/Iot3W2XJk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UHAlcFdSi6ydMBSIkDFrXsfAftRxZkwF+uERuKLzOXWBaKRqoC11Ii4AqbbYp9hhE OiuF+ptu+tEBMeKLJrQbv31WAPJ0s+KbV0tOR0l5dAiRyKMIiYSBfmU0IOYisTT5dm RgJwKGhTmpdq+KcVvvqfpr+3Q+OzeUZ2usuzR6y0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Isaac J. Manjarres" , Prasad Sodagudi , William Kucharski , Kees Cook , Greg Kroah-Hartman , Trilok Soni , Andrew Morton , Linus Torvalds Subject: [PATCH 5.2 010/135] mm/usercopy: use memory range to be accessed for wraparound check Date: Thu, 22 Aug 2019 13:06:06 -0400 Message-Id: <20190822170811.13303-11-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190822170811.13303-1-sashal@kernel.org> References: <20190822170811.13303-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.2.10-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.2.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.2.10-rc1 X-KernelTest-Deadline: 2019-08-24T17:07+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Isaac J. Manjarres" commit 951531691c4bcaa59f56a316e018bc2ff1ddf855 upstream. Currently, when checking to see if accessing n bytes starting at address "ptr" will cause a wraparound in the memory addresses, the check in check_bogus_address() adds an extra byte, which is incorrect, as the range of addresses that will be accessed is [ptr, ptr + (n - 1)]. This can lead to incorrectly detecting a wraparound in the memory address, when trying to read 4 KB from memory that is mapped to the the last possible page in the virtual address space, when in fact, accessing that range of memory would not cause a wraparound to occur. Use the memory range that will actually be accessed when considering if accessing a certain amount of bytes will cause the memory address to wrap around. Link: http://lkml.kernel.org/r/1564509253-23287-1-git-send-email-isaacm@codeaurora.org Fixes: f5509cc18daa ("mm: Hardened usercopy") Signed-off-by: Prasad Sodagudi Signed-off-by: Isaac J. Manjarres Co-developed-by: Prasad Sodagudi Reviewed-by: William Kucharski Acked-by: Kees Cook Cc: Greg Kroah-Hartman Cc: Trilok Soni Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/usercopy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/usercopy.c b/mm/usercopy.c index 2a09796edef8d..98e924864554c 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -147,7 +147,7 @@ static inline void check_bogus_address(const unsigned long ptr, unsigned long n, bool to_user) { /* Reject if object wraps past end of memory. */ - if (ptr + n < ptr) + if (ptr + (n - 1) < ptr) usercopy_abort("wrapped address", NULL, to_user, 0, ptr + n); /* Reject if NULL or ZERO-allocation. */ -- 2.20.1