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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 DF015C433E6 for ; Wed, 23 Dec 2020 17:43:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A997D22286 for ; Wed, 23 Dec 2020 17:43:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728113AbgLWRn0 (ORCPT ); Wed, 23 Dec 2020 12:43:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726424AbgLWRnZ (ORCPT ); Wed, 23 Dec 2020 12:43:25 -0500 Received: from mail.skyhub.de (mail.skyhub.de [IPv6:2a01:4f8:190:11c2::b:1457]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 108DAC0617A6 for ; Wed, 23 Dec 2020 09:42:45 -0800 (PST) Received: from zn.tnic (p200300ec2f0de600b74d534b1676c98b.dip0.t-ipconnect.de [IPv6:2003:ec:2f0d:e600:b74d:534b:1676:c98b]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 8CA781EC0523; Wed, 23 Dec 2020 18:42:43 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1608745363; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=zGB/vH4Jniwdgk7zkgw0KjQfWC0SQJDo/NXJ7wbYNlE=; b=njKJyTl4pQOc2EMQKnxmYJBNkOwaSpSJweVC0NKlIb8gak9h0hmvqjoEhmbkQo43xmmfNT 7WFogBUYBdjsBAlu4D2b9Af1hfhrX2B4aqIZU1zqsimXbBvkquKRjd+91TfsuRrycPevvP NtSS5ukNgsZQAjwfBtXQdk294eQkuMk= From: Borislav Petkov To: Andy Lutomirski , Masami Hiramatsu Cc: X86 ML , LKML Subject: [PATCH v1 04/19] x86/insn-eval: Handle return values from the decoder Date: Wed, 23 Dec 2020 18:42:18 +0100 Message-Id: <20201223174233.28638-5-bp@alien8.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201223174233.28638-1-bp@alien8.de> References: <20201223174233.28638-1-bp@alien8.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov Now that the different instruction-inspecting functions return a value, test that and return early from callers if error has been encountered. While at it, do not call insn_get_modrm() when calling insn_get_displacement() because latter will make sure to call insn_get_modrm() if ModRM hasn't been parsed yet. Signed-off-by: Borislav Petkov --- arch/x86/lib/insn-eval.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index 265d23a0c334..7e49aaf5454c 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -1106,18 +1106,21 @@ static int get_eff_addr_modrm_16(struct insn *insn, struct pt_regs *regs, * @base_offset will have a register, as an offset from the base of pt_regs, * that can be used to resolve the associated segment. * - * -EINVAL on error. + * Negative value on error. */ static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs, int *base_offset, long *eff_addr) { long base, indx; int indx_offset; + int ret; if (insn->addr_bytes != 8 && insn->addr_bytes != 4) return -EINVAL; - insn_get_modrm(insn); + ret = insn_get_modrm(insn); + if (ret) + return ret; if (!insn->modrm.nbytes) return -EINVAL; @@ -1125,7 +1128,9 @@ static int get_eff_addr_sib(struct insn *insn, struct pt_regs *regs, if (X86_MODRM_MOD(insn->modrm.value) > 2) return -EINVAL; - insn_get_sib(insn); + ret = insn_get_sib(insn); + if (ret) + return ret; if (!insn->sib.nbytes) return -EINVAL; @@ -1194,8 +1199,8 @@ static void __user *get_addr_ref_16(struct insn *insn, struct pt_regs *regs) short eff_addr; long tmp; - insn_get_modrm(insn); - insn_get_displacement(insn); + if (insn_get_displacement(insn)) + goto out; if (insn->addr_bytes != 2) goto out; @@ -1491,7 +1496,9 @@ bool insn_decode_regs(struct insn *insn, struct pt_regs *regs, insn->addr_bytes = INSN_CODE_SEG_ADDR_SZ(seg_defs); insn->opnd_bytes = INSN_CODE_SEG_OPND_SZ(seg_defs); - insn_get_length(insn); + if (insn_get_length(insn)) + return false; + if (buf_size < insn->length) return false; -- 2.29.2