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=-9.0 required=3.0 tests=DATE_IN_PAST_06_12, 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 974DBC4740C for ; Mon, 9 Sep 2019 22:16:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5714A21D82 for ; Mon, 9 Sep 2019 22:16:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568067411; bh=cA0/ajFdxMeE7KcBnjMNO94Hp7DUcbWHvPWzYGo6SCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Pvd2sOeMdKinCPdtrpAqxfbHBvVgB6ny9XXTJsHDWwYppbIBmrZneFioWSlpCoEuR ovrzc1BddTb31DUQGWHUNjuYzYDQYU5G6GAaPzKF0dpQJLpYDUXkzPPrzF6+K4cx1K R0A/JjUiLjqvI8/B/rHvEcnTJ8IekIb4ElTQ6G6s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406242AbfIIWQt (ORCPT ); Mon, 9 Sep 2019 18:16:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:45660 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2406221AbfIIWQr (ORCPT ); Mon, 9 Sep 2019 18:16:47 -0400 Received: from sasha-vm.mshome.net (unknown [62.28.240.114]) (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 DA5D721A4A; Mon, 9 Sep 2019 22:16:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1568067406; bh=cA0/ajFdxMeE7KcBnjMNO94Hp7DUcbWHvPWzYGo6SCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kVTSKDmxouI/xgDgqXI2lGlp8eeosOcupZ9J8NbQ2ORKRe/qXsNLHaPf5a0BCEe6d pS7jKOtDMDp84bRhPMJefxPQ5HVnWc0m6WYE6CgwS4Se32hiEhydsenWIwu40a5jTw qO35hp+4MN02bf8Lf8RE7lpbWVpsA3vqDR/DLjMo= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tianyu Lan , Jong Hyun Park , Michael Kelley , Borislav Petkov , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Sasha Levin , linux-hyperv@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 4/8] x86/hyper-v: Fix overflow bug in fill_gva_list() Date: Mon, 9 Sep 2019 11:41:19 -0400 Message-Id: <20190909154124.31146-4-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190909154124.31146-1-sashal@kernel.org> References: <20190909154124.31146-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tianyu Lan [ Upstream commit 4030b4c585c41eeefec7bd20ce3d0e100a0f2e4d ] When the 'start' parameter is >= 0xFF000000 on 32-bit systems, or >= 0xFFFFFFFF'FF000000 on 64-bit systems, fill_gva_list() gets into an infinite loop. With such inputs, 'cur' overflows after adding HV_TLB_FLUSH_UNIT and always compares as less than end. Memory is filled with guest virtual addresses until the system crashes. Fix this by never incrementing 'cur' to be larger than 'end'. Reported-by: Jong Hyun Park Signed-off-by: Tianyu Lan Reviewed-by: Michael Kelley Cc: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: 2ffd9e33ce4a ("x86/hyper-v: Use hypercall for remote TLB flush") Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- arch/x86/hyperv/mmu.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/hyperv/mmu.c b/arch/x86/hyperv/mmu.c index ef5f29f913d7b..2f34d52753526 100644 --- a/arch/x86/hyperv/mmu.c +++ b/arch/x86/hyperv/mmu.c @@ -37,12 +37,14 @@ static inline int fill_gva_list(u64 gva_list[], int offset, * Lower 12 bits encode the number of additional * pages to flush (in addition to the 'cur' page). */ - if (diff >= HV_TLB_FLUSH_UNIT) + if (diff >= HV_TLB_FLUSH_UNIT) { gva_list[gva_n] |= ~PAGE_MASK; - else if (diff) + cur += HV_TLB_FLUSH_UNIT; + } else if (diff) { gva_list[gva_n] |= (diff - 1) >> PAGE_SHIFT; + cur = end; + } - cur += HV_TLB_FLUSH_UNIT; gva_n++; } while (cur < end); -- 2.20.1