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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA5EDC433F5 for ; Mon, 27 Sep 2021 17:21:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3CF3610E8 for ; Mon, 27 Sep 2021 17:21:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236185AbhI0RWt (ORCPT ); Mon, 27 Sep 2021 13:22:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:36852 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236847AbhI0RTj (ORCPT ); Mon, 27 Sep 2021 13:19:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E3D73611EF; Mon, 27 Sep 2021 17:12:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632762771; bh=2xoO9EbBO3BATnGBf8H6ObRb99Rb93yV4/QlF5JSOhg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=C19xmNlyzyhYGtLQ/2n20RDqJJvQfLiK1qIkv4jhmPoZRbEh0ldi7SWcBWS1fPs6T n8UhOspduLrfJwcijM9tvRaRi9za+5ddrnZ+tnDEFRF1rbM+PJb4JizoTHBmft1kNh vWay7OXl7cT4IKXpowb6Vcd2eloxVu8iaxgBBMGY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Branislav Rankov , Robin Murphy , Mark Rutland , Catalin Marinas Subject: [PATCH 5.14 045/162] arm64: Mitigate MTE issues with str{n}cmp() Date: Mon, 27 Sep 2021 19:01:31 +0200 Message-Id: <20210927170235.061650896@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210927170233.453060397@linuxfoundation.org> References: <20210927170233.453060397@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Robin Murphy commit 59a68d4138086c015ab8241c3267eec5550fbd44 upstream. As with strlen(), the patches importing the updated str{n}cmp() implementations were originally developed and tested before the advent of CONFIG_KASAN_HW_TAGS, and have subsequently revealed not to be MTE-safe. Since in-kernel MTE is still a rather niche case, let it temporarily fall back to the generic C versions for correctness until we can figure out the best fix. Fixes: 758602c04409 ("arm64: Import latest version of Cortex Strings' strcmp") Fixes: 020b199bc70d ("arm64: Import latest version of Cortex Strings' strncmp") Cc: # 5.14.x Reported-by: Branislav Rankov Signed-off-by: Robin Murphy Acked-by: Mark Rutland Link: https://lore.kernel.org/r/34dc4d12eec0adae49b0ac927df642ed10089d40.1631890770.git.robin.murphy@arm.com Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/assembler.h | 5 +++++ arch/arm64/include/asm/string.h | 2 ++ arch/arm64/lib/strcmp.S | 2 +- arch/arm64/lib/strncmp.S | 2 +- 4 files changed, 9 insertions(+), 2 deletions(-) --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -525,6 +525,11 @@ alternative_endif #define EXPORT_SYMBOL_NOKASAN(name) EXPORT_SYMBOL(name) #endif +#ifdef CONFIG_KASAN_HW_TAGS +#define EXPORT_SYMBOL_NOHWKASAN(name) +#else +#define EXPORT_SYMBOL_NOHWKASAN(name) EXPORT_SYMBOL_NOKASAN(name) +#endif /* * Emit a 64-bit absolute little endian symbol reference in a way that * ensures that it will be resolved at build time, even when building a --- a/arch/arm64/include/asm/string.h +++ b/arch/arm64/include/asm/string.h @@ -12,11 +12,13 @@ extern char *strrchr(const char *, int c #define __HAVE_ARCH_STRCHR extern char *strchr(const char *, int c); +#ifndef CONFIG_KASAN_HW_TAGS #define __HAVE_ARCH_STRCMP extern int strcmp(const char *, const char *); #define __HAVE_ARCH_STRNCMP extern int strncmp(const char *, const char *, __kernel_size_t); +#endif #define __HAVE_ARCH_STRLEN extern __kernel_size_t strlen(const char *); --- a/arch/arm64/lib/strcmp.S +++ b/arch/arm64/lib/strcmp.S @@ -173,4 +173,4 @@ L(done): ret SYM_FUNC_END_PI(strcmp) -EXPORT_SYMBOL_NOKASAN(strcmp) +EXPORT_SYMBOL_NOHWKASAN(strcmp) --- a/arch/arm64/lib/strncmp.S +++ b/arch/arm64/lib/strncmp.S @@ -258,4 +258,4 @@ L(ret0): ret SYM_FUNC_END_PI(strncmp) -EXPORT_SYMBOL_NOKASAN(strncmp) +EXPORT_SYMBOL_NOHWKASAN(strncmp)