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=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 DC403C64E7A for ; Thu, 3 Dec 2020 04:52:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 88ED4208A9 for ; Thu, 3 Dec 2020 04:52:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727886AbgLCEvr (ORCPT ); Wed, 2 Dec 2020 23:51:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:47998 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbgLCEvr (ORCPT ); Wed, 2 Dec 2020 23:51:47 -0500 From: Masami Hiramatsu Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: x86@kernel.org, Thomas Gleixner , Ingo Molnar , Borislav Petkov Cc: Kees Cook , Masami Hiramatsu , "H . Peter Anvin" , Joerg Roedel , Tom Lendacky , "Gustavo A . R . Silva" , Jann Horn , Srikar Dronamraju , Ricardo Neri , linux-kernel@vger.kernel.org Subject: [PATCH v2 3/3] x86/sev-es: Fix not using prefixes.nbytes for loop over prefixes.bytes Date: Thu, 3 Dec 2020 13:51:01 +0900 Message-Id: <160697106089.3146288.2052422845039649176.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <160697102582.3146288.10127018634865687932.stgit@devnote2> References: <160697102582.3146288.10127018634865687932.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since the insn.prefixes.nbytes can be bigger than the size of insn.prefixes.bytes[] when a same prefix is repeated, we have to check whether the i < 4 and insn.prefixes.bytes[i] != 0 instead of insn.prefixes.nbytes. Fixes: 25189d08e516 ("x86/sev-es: Add support for handling IOIO exceptions") Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com Debugged-by: Kees Cook Signed-off-by: Masami Hiramatsu --- arch/x86/boot/compressed/sev-es.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/boot/compressed/sev-es.c b/arch/x86/boot/compressed/sev-es.c index 954cb2702e23..27826c265aab 100644 --- a/arch/x86/boot/compressed/sev-es.c +++ b/arch/x86/boot/compressed/sev-es.c @@ -32,13 +32,12 @@ struct ghcb *boot_ghcb; */ static bool insn_has_rep_prefix(struct insn *insn) { + insn_byte_t p; int i; insn_get_prefixes(insn); - for (i = 0; i < insn->prefixes.nbytes; i++) { - insn_byte_t p = insn->prefixes.bytes[i]; - + for_each_insn_prefix(insn, i, p) { if (p == 0xf2 || p == 0xf3) return true; }