From patchwork Thu Dec 10 14:27:31 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 341873 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 A997BC433FE for ; Thu, 10 Dec 2020 16:55:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BEAC2067B for ; Thu, 10 Dec 2020 16:55:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392031AbgLJQyo (ORCPT ); Thu, 10 Dec 2020 11:54:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:43578 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391052AbgLJOgw (ORCPT ); Thu, 10 Dec 2020 09:36:52 -0500 From: Greg Kroah-Hartman Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com, Masami Hiramatsu , Borislav Petkov , Sudip Mukherjee Subject: [PATCH 5.4 54/54] x86/insn-eval: Use new for_each_insn_prefix() macro to loop over prefixes bytes Date: Thu, 10 Dec 2020 15:27:31 +0100 Message-Id: <20201210142604.674205207@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201210142602.037095225@linuxfoundation.org> References: <20201210142602.037095225@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Masami Hiramatsu commit 12cb908a11b2544b5f53e9af856e6b6a90ed5533 upstream Since insn.prefixes.nbytes can be bigger than the size of insn.prefixes.bytes[] when a prefix is repeated, the proper check must be insn.prefixes.bytes[i] != 0 and i < 4 instead of using insn.prefixes.nbytes. Use the new for_each_insn_prefix() macro which does it correctly. Debugged by Kees Cook . [ bp: Massage commit message. ] Fixes: 32d0b95300db ("x86/insn-eval: Add utility functions to get segment selector") Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com Signed-off-by: Masami Hiramatsu Signed-off-by: Borislav Petkov Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/160697104969.3146288.16329307586428270032.stgit@devnote2 [sudip: adjust context] Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman --- arch/x86/lib/insn-eval.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -70,14 +70,15 @@ static int get_seg_reg_override_idx(stru { int idx = INAT_SEG_REG_DEFAULT; int num_overrides = 0, i; + insn_byte_t p; insn_get_prefixes(insn); /* Look for any segment override prefixes. */ - for (i = 0; i < insn->prefixes.nbytes; i++) { + for_each_insn_prefix(insn, i, p) { insn_attr_t attr; - attr = inat_get_opcode_attribute(insn->prefixes.bytes[i]); + attr = inat_get_opcode_attribute(p); switch (attr) { case INAT_MAKE_PREFIX(INAT_PFX_CS): idx = INAT_SEG_REG_CS;