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=-20.8 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,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 64F50C43331 for ; Mon, 15 Mar 2021 15:48:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E0E764F22 for ; Mon, 15 Mar 2021 15:48:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233861AbhCOPsi (ORCPT ); Mon, 15 Mar 2021 11:48:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232270AbhCOPsB (ORCPT ); Mon, 15 Mar 2021 11:48:01 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 923D5C0613DF; Mon, 15 Mar 2021 08:47:53 -0700 (PDT) Date: Mon, 15 Mar 2021 15:47:48 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1615823269; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/Iy0EXFAOKCEIJt0bqlzzIHdW6J20TYlKyqis8i6oJw=; b=Mu2+CRPZL/HGJpyxDsrt7E0iw5cvjcvsLBjPWWXGACHJ1NpOX41ahEa1uoZIUVBxfjsiE0 CbVg7ULU/itF/efVQqv1w4ptxhlr+HIe+k0eZyfz+xcCFh71ZfH2/9lk4GLNLKzQ9c20v4 VKljEgwIIH+HP1bNe6w7XZXyDSoSPwrpC9l5d44l/YwCVZZQigqLbyffoEuOhP1hBRPrvS 91i5LqjlLaAyMKxtd3p/wPYSu8JQnqFIPtS4Ms0Yp5ZeW5Ka9ODoE0zzZNAVYrDtlC+LdZ YoxhNt+YtqKvM5m0aDJbLsPXtrZc6pNmTEVfniKUjXKkAMkARui7C8pAmGxrhQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1615823269; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/Iy0EXFAOKCEIJt0bqlzzIHdW6J20TYlKyqis8i6oJw=; b=ojUDfgrLLh8C+XMvtHZmgRpQP7nnjJomv5lmGeZo1zdOZc6ygfYummUx047x9o9wBhmKpk M/dhzV2TyLJjw8AA== From: "tip-bot2 for Borislav Petkov" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/core] x86/insn-eval: Handle return values from the decoder Cc: Borislav Petkov , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20210304174237.31945-6-bp@alien8.de> References: <20210304174237.31945-6-bp@alien8.de> MIME-Version: 1.0 Message-ID: <161582326863.398.12655944025614758313.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the x86/core branch of tip: Commit-ID: 6e8c83d2a3afbfd5ee019ec720b75a42df515caa Gitweb: https://git.kernel.org/tip/6e8c83d2a3afbfd5ee019ec720b75a42df515caa Author: Borislav Petkov AuthorDate: Thu, 19 Nov 2020 19:20:18 +01:00 Committer: Borislav Petkov CommitterDate: Mon, 15 Mar 2021 11:12:15 +01:00 x86/insn-eval: Handle return values from the decoder 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 Link: https://lkml.kernel.org/r/20210304174237.31945-6-bp@alien8.de --- arch/x86/lib/insn-eval.c | 34 +++++++++++++++++++++------------- 1 file changed, 21 insertions(+), 13 deletions(-) diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c index 422a592..321a157 100644 --- a/arch/x86/lib/insn-eval.c +++ b/arch/x86/lib/insn-eval.c @@ -924,10 +924,11 @@ static int get_seg_base_limit(struct insn *insn, struct pt_regs *regs, static int get_eff_addr_reg(struct insn *insn, struct pt_regs *regs, int *regoff, long *eff_addr) { - insn_get_modrm(insn); + int ret; - if (!insn->modrm.nbytes) - return -EINVAL; + ret = insn_get_modrm(insn); + if (ret) + return ret; if (X86_MODRM_MOD(insn->modrm.value) != 3) return -EINVAL; @@ -973,14 +974,14 @@ static int get_eff_addr_modrm(struct insn *insn, struct pt_regs *regs, int *regoff, long *eff_addr) { long tmp; + int ret; if (insn->addr_bytes != 8 && insn->addr_bytes != 4) return -EINVAL; - insn_get_modrm(insn); - - if (!insn->modrm.nbytes) - return -EINVAL; + ret = insn_get_modrm(insn); + if (ret) + return ret; if (X86_MODRM_MOD(insn->modrm.value) > 2) return -EINVAL; @@ -1102,18 +1103,21 @@ 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; @@ -1121,7 +1125,9 @@ 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; @@ -1190,8 +1196,8 @@ 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; @@ -1525,7 +1531,9 @@ bool insn_decode_from_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;