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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 72D04C4338F for ; Tue, 24 Aug 2021 17:37:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 50E71610D1 for ; Tue, 24 Aug 2021 17:37:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241078AbhHXRif (ORCPT ); Tue, 24 Aug 2021 13:38:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:41186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242355AbhHXRfJ (ORCPT ); Tue, 24 Aug 2021 13:35:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3742761BC1; Tue, 24 Aug 2021 17:06:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629824807; bh=Astv9Y1lGkmZ6IPwhybz40DQskpH+ZmQ1aj00HYuO5g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=junMbsQpNWrWz4ygv7W/eW5nhvt3cZPFT0BsON/A32Ds7qslxVQhegG2u/fBhxqWi UjormD08dBKbfobqvomvFnSOMAVT+VBXMu/vgaD58SM9PvFjUXCW9rp5eh2CcJXr3e hD1iAMOb9W1BEUDWjGBRDeXqCVR12Qsymm9KqzgdinyRm85qK/4nfAsRQ8TkR5H+L8 ngP3MFMIw5urLfCMSFlsSILGtfifBi4z976JpywYOIxFH0FTeDUjtYJdABRrG1exXm V0s0D48tcwnj20Y4JAtQ4AuV8HYqh1oN5SHAVUkARfelV4pwY4aqHeMa8wPv2QkvzP AwZah3xdcqsSQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Xie Yongji , Jason Wang , "Michael S . Tsirkin" , Sasha Levin Subject: [PATCH 4.9 32/43] vhost: Fix the calculation in vhost_overflow() Date: Tue, 24 Aug 2021 13:06:03 -0400 Message-Id: <20210824170614.710813-33-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210824170614.710813-1-sashal@kernel.org> References: <20210824170614.710813-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.9.281-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.9.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.9.281-rc1 X-KernelTest-Deadline: 2021-08-26T17:06+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xie Yongji [ Upstream commit f7ad318ea0ad58ebe0e595e59aed270bb643b29b ] This fixes the incorrect calculation for integer overflow when the last address of iova range is 0xffffffff. Fixes: ec33d031a14b ("vhost: detect 32 bit integer wrap around") Reported-by: Jason Wang Signed-off-by: Xie Yongji Acked-by: Jason Wang Link: https://lore.kernel.org/r/20210728130756.97-2-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin --- drivers/vhost/vhost.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index d2431afeda84..62c61a283b35 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -675,10 +675,16 @@ static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); } +/* Make sure 64 bit math will not overflow. */ static bool vhost_overflow(u64 uaddr, u64 size) { - /* Make sure 64 bit math will not overflow. */ - return uaddr > ULONG_MAX || size > ULONG_MAX || uaddr > ULONG_MAX - size; + if (uaddr > ULONG_MAX || size > ULONG_MAX) + return true; + + if (!size) + return false; + + return uaddr > ULONG_MAX - size + 1; } /* Caller should have vq mutex and device mutex. */ -- 2.30.2