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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38D8EC7618A for ; Mon, 20 Mar 2023 15:03:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231479AbjCTPD5 (ORCPT ); Mon, 20 Mar 2023 11:03:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231955AbjCTPD0 (ORCPT ); Mon, 20 Mar 2023 11:03:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 33D962E818 for ; Mon, 20 Mar 2023 07:59:31 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id C9398B80ECA for ; Mon, 20 Mar 2023 14:59:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 251D8C433D2; Mon, 20 Mar 2023 14:59:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1679324367; bh=c4du/Yd/+K3ZjQy2a3poNfNcNLvRrgxix1oesLeWU/s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gg1Qc7fYxQ3pHOsNwjiTMC4KPcaI9qu4jgRbPo0i0outL2D1lvRhVJ2D5oDHZwmZI MZSi7HxAAUDcZQAIEevVM+7Wj3jxXhyOMgdmph4/RlstuBu6Ew1jmC7bDU95v7qgUU +b6qmaAptEiwNL8NdNRPNgGFTjUdz8bmHbNPGLJQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nikita Zhandarovich , "Borislav Petkov (AMD)" , Tom Lendacky , stable@kernel.org Subject: [PATCH 4.19 32/36] x86/mm: Fix use of uninitialized buffer in sme_enable() Date: Mon, 20 Mar 2023 15:54:58 +0100 Message-Id: <20230320145425.433875798@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230320145424.191578432@linuxfoundation.org> References: <20230320145424.191578432@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Nikita Zhandarovich commit cbebd68f59f03633469f3ecf9bea99cd6cce3854 upstream. cmdline_find_option() may fail before doing any initialization of the buffer array. This may lead to unpredictable results when the same buffer is used later in calls to strncmp() function. Fix the issue by returning early if cmdline_find_option() returns an error. Found by Linux Verification Center (linuxtesting.org) with static analysis tool SVACE. Fixes: aca20d546214 ("x86/mm: Add support to make use of Secure Memory Encryption") Signed-off-by: Nikita Zhandarovich Signed-off-by: Borislav Petkov (AMD) Acked-by: Tom Lendacky Cc: Link: https://lore.kernel.org/r/20230306160656.14844-1-n.zhandarovich@fintech.ru Signed-off-by: Greg Kroah-Hartman --- arch/x86/mm/mem_encrypt_identity.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/mm/mem_encrypt_identity.c +++ b/arch/x86/mm/mem_encrypt_identity.c @@ -563,7 +563,8 @@ void __init sme_enable(struct boot_param cmdline_ptr = (const char *)((u64)bp->hdr.cmd_line_ptr | ((u64)bp->ext_cmd_line_ptr << 32)); - cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer)); + if (cmdline_find_option(cmdline_ptr, cmdline_arg, buffer, sizeof(buffer)) < 0) + return; if (!strncmp(buffer, cmdline_on, sizeof(buffer))) sme_me_mask = me_mask;