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=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,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 F1BCFC282CE for ; Wed, 24 Apr 2019 17:13:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C115E21900 for ; Wed, 24 Apr 2019 17:13:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556125998; bh=BhA/5EtCpsFz+7+fREpuApLVcW9Z87+ouqrHBogYnTc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PSw0f7+Fnfz2Auh+x7TOcy6FH1f6PJH/Gchf9NumCEknyzeFczvaXShfcNo7tffEb YvIXzJaeuLveZihnLHBjbDRWyaSDMG85bGS6OpZFJMoFXP/p5idiilBUgGuWZXjuPV KKY9Go+ounpDgzYWWOVZ6yK75xfbf39+949zYBb0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387427AbfDXRNR (ORCPT ); Wed, 24 Apr 2019 13:13:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:37284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387839AbfDXRNP (ORCPT ); Wed, 24 Apr 2019 13:13:15 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 631C721900; Wed, 24 Apr 2019 17:13:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556125994; bh=BhA/5EtCpsFz+7+fREpuApLVcW9Z87+ouqrHBogYnTc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EhZvVh+c9BtKQNzqPvi2J4EO4mtN5kIqcDEAGwsS+LTfvANa33IZplfH4aIyoIklZ RFmNUCjeRH+U1BX+uQybPbMN3fpivgzHAWkBw27wRlrGwuYL3RyJkiz1owNTVB8dYx ssW8q2x05oXb4H4abbzGkpOF/l+fZAzby8V6c2UQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Boris Ostrovsky , Juergen Gross Subject: [PATCH 3.18 056/104] xen: Prevent buffer overflow in privcmd ioctl Date: Wed, 24 Apr 2019 19:09:13 +0200 Message-Id: <20190424170902.788752710@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170839.996641496@linuxfoundation.org> References: <20190424170839.996641496@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dan Carpenter commit 42d8644bd77dd2d747e004e367cb0c895a606f39 upstream. The "call" variable comes from the user in privcmd_ioctl_hypercall(). It's an offset into the hypercall_page[] which has (PAGE_SIZE / 32) elements. We need to put an upper bound on it to prevent an out of bounds access. Cc: stable@vger.kernel.org Fixes: 1246ae0bb992 ("xen: add variable hypercall caller") Signed-off-by: Dan Carpenter Reviewed-by: Boris Ostrovsky Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/xen/hypercall.h | 3 +++ 1 file changed, 3 insertions(+) --- a/arch/x86/include/asm/xen/hypercall.h +++ b/arch/x86/include/asm/xen/hypercall.h @@ -213,6 +213,9 @@ privcmd_call(unsigned call, __HYPERCALL_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5); + if (call >= PAGE_SIZE / sizeof(hypercall_page[0])) + return -EINVAL; + asm volatile("call *%[call]" : __HYPERCALL_5PARAM : [call] "a" (&hypercall_page[call])