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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 B4ABBC433DF for ; Tue, 9 Jun 2020 18:24:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A158C2067B for ; Tue, 9 Jun 2020 18:24:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389115AbgFISYJ (ORCPT ); Tue, 9 Jun 2020 14:24:09 -0400 Received: from foss.arm.com ([217.140.110.172]:45998 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730588AbgFIRrD (ORCPT ); Tue, 9 Jun 2020 13:47:03 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 45AD51F1; Tue, 9 Jun 2020 10:47:02 -0700 (PDT) Received: from e121166-lin.cambridge.arm.com (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A21CA3F73D; Tue, 9 Jun 2020 10:47:00 -0700 (PDT) Date: Tue, 9 Jun 2020 18:46:54 +0100 From: Lorenzo Pieralisi To: Nick Desaulniers Cc: Will Deacon , Catalin Marinas , stable@vger.kernel.org, Ard Biesheuvel , Enrico Weigelt , Allison Randal , Jeremy Linton , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] arm64: acpi: fix UBSAN warning Message-ID: <20200609174654.GA2994@e121166-lin.cambridge.arm.com> References: <20200608203818.189423-1-ndesaulniers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200608203818.189423-1-ndesaulniers@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 08, 2020 at 01:38:17PM -0700, Nick Desaulniers wrote: > Will reported a UBSAN warning: > > UBSAN: null-ptr-deref in arch/arm64/kernel/smp.c:596:6 > member access within null pointer of type 'struct acpi_madt_generic_interrupt' > CPU: 0 PID: 0 Comm: swapper Not tainted 5.7.0-rc6-00124-g96bc42ff0a82 #1 > Call trace: > dump_backtrace+0x0/0x384 > show_stack+0x28/0x38 > dump_stack+0xec/0x174 > handle_null_ptr_deref+0x134/0x174 > __ubsan_handle_type_mismatch_v1+0x84/0xa4 > acpi_parse_gic_cpu_interface+0x60/0xe8 > acpi_parse_entries_array+0x288/0x498 > acpi_table_parse_entries_array+0x178/0x1b4 > acpi_table_parse_madt+0xa4/0x110 > acpi_parse_and_init_cpus+0x38/0x100 > smp_init_cpus+0x74/0x258 > setup_arch+0x350/0x3ec > start_kernel+0x98/0x6f4 > > This is from the use of the ACPI_OFFSET in > arch/arm64/include/asm/acpi.h. Replace its use with offsetof from > include/linux/stddef.h which should implement the same logic using > __builtin_offsetof, so that UBSAN wont warn. > > Link: https://lore.kernel.org/lkml/20200521100952.GA5360@willie-the-truck/ > Cc: stable@vger.kernel.org > Reported-by: Will Deacon > Suggested-by: Ard Biesheuvel > Signed-off-by: Nick Desaulniers > --- > Changes V1 -> V2: > * Just fix one of the two warnings, specific to arm64. > * Put warning in commit message. > > arch/arm64/include/asm/acpi.h | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) Acked-by: Lorenzo Pieralisi > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > index b263e239cb59..a45366c3909b 100644 > --- a/arch/arm64/include/asm/acpi.h > +++ b/arch/arm64/include/asm/acpi.h > @@ -12,6 +12,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -31,14 +32,14 @@ > * is therefore used to delimit the MADT GICC structure minimum length > * appropriately. > */ > -#define ACPI_MADT_GICC_MIN_LENGTH ACPI_OFFSET( \ > +#define ACPI_MADT_GICC_MIN_LENGTH offsetof( \ > struct acpi_madt_generic_interrupt, efficiency_class) > > #define BAD_MADT_GICC_ENTRY(entry, end) \ > (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \ > (unsigned long)(entry) + (entry)->header.length > (end)) > > -#define ACPI_MADT_GICC_SPE (ACPI_OFFSET(struct acpi_madt_generic_interrupt, \ > +#define ACPI_MADT_GICC_SPE (offsetof(struct acpi_madt_generic_interrupt, \ > spe_interrupt) + sizeof(u16)) > > /* Basic configuration for ACPI */ > -- > 2.27.0.278.ge193c7cf3a9-goog >