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,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 D88EDC10F12 for ; Mon, 15 Apr 2019 19:09:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5EC820693 for ; Mon, 15 Apr 2019 19:09:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355343; bh=e2tOFBoU5wYtkPRHkaxNc1B5wnVXy5OOuGbYz/kMnbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=utkQkymUz4Rrvemzy4pKUaQ871fHWasnFfw0RL3lfLuXsd0NWCCi1Qk4LVDl4gxPY YMqFemmm7vGd+IcqrHvNrCiIDhXilXoYEuWqHsk3vDc7U9kxsIHNUcM6COsrZlKglc smBEGyAkTMso1Re2SCPen6t42XxI7oWNoRWfrs8E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730068AbfDOTJC (ORCPT ); Mon, 15 Apr 2019 15:09:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:44588 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730075AbfDOTJA (ORCPT ); Mon, 15 Apr 2019 15:09:00 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 8CAC4218FE; Mon, 15 Apr 2019 19:08:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1555355340; bh=e2tOFBoU5wYtkPRHkaxNc1B5wnVXy5OOuGbYz/kMnbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YPYz0yXtLdnonxdiwxszdt30QobUIPQLN4IL9rNzqSu/TQe8U3cj24NzEPHFQv6Jd DbWLQP12FdovAZ1t6GAkf6hcWk2xcJ5rb2uPWto2DvICFAUb3xuNgv4Azjzg+HjzT2 q1z35l2fVLl3SYmKANsAm0mJCVWrGr0yXnMfYm9k= 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 4.19 083/101] xen: Prevent buffer overflow in privcmd ioctl Date: Mon, 15 Apr 2019 20:59:21 +0200 Message-Id: <20190415183744.798949630@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190415183740.341577907@linuxfoundation.org> References: <20190415183740.341577907@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -206,6 +206,9 @@ xen_single_call(unsigned int call, __HYPERCALL_DECLS; __HYPERCALL_5ARG(a1, a2, a3, a4, a5); + if (call >= PAGE_SIZE / sizeof(hypercall_page[0])) + return -EINVAL; + asm volatile(CALL_NOSPEC : __HYPERCALL_5PARAM : [thunk_target] "a" (&hypercall_page[call])