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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 42822C18E5B for ; Tue, 17 Mar 2020 14:38:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 23170206EC for ; Tue, 17 Mar 2020 14:38:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726683AbgCQOik (ORCPT ); Tue, 17 Mar 2020 10:38:40 -0400 Received: from foss.arm.com ([217.140.110.172]:39076 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726112AbgCQOij (ORCPT ); Tue, 17 Mar 2020 10:38:39 -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 19D3630E; Tue, 17 Mar 2020 07:38:39 -0700 (PDT) Received: from arrakis.emea.arm.com (arrakis.cambridge.arm.com [10.1.196.71]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 241AA3F534; Tue, 17 Mar 2020 07:38:36 -0700 (PDT) Date: Tue, 17 Mar 2020 14:38:34 +0000 From: Catalin Marinas To: Vincenzo Frascino Cc: linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, linux-mips@vger.kernel.org, x86@kernel.org, Will Deacon , Arnd Bergmann , Russell King , Paul Burton , Thomas Gleixner , Andy Lutomirski , Ingo Molnar , Borislav Petkov , Stephen Boyd , Mark Salyzyn , Kees Cook , Peter Collingbourne , Dmitry Safonov <0x7f454c46@gmail.com>, Andrei Vagin , Nick Desaulniers , Marc Zyngier , Mark Rutland , Will Deacon Subject: Re: [PATCH v4 18/26] arm64: vdso32: Replace TASK_SIZE_32 check in vgettimeofday Message-ID: <20200317143834.GC632169@arrakis.emea.arm.com> References: <20200317122220.30393-1-vincenzo.frascino@arm.com> <20200317122220.30393-19-vincenzo.frascino@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200317122220.30393-19-vincenzo.frascino@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 17, 2020 at 12:22:12PM +0000, Vincenzo Frascino wrote: > diff --git a/arch/arm64/kernel/vdso32/vgettimeofday.c b/arch/arm64/kernel/vdso32/vgettimeofday.c > index 54fc1c2ce93f..91138077b073 100644 > --- a/arch/arm64/kernel/vdso32/vgettimeofday.c > +++ b/arch/arm64/kernel/vdso32/vgettimeofday.c > @@ -8,11 +8,14 @@ > #include > #include > > +#define VALID_CLOCK_ID(x) \ > + ((x >= 0) && (x < VDSO_BASES)) > + > int __vdso_clock_gettime(clockid_t clock, > struct old_timespec32 *ts) > { > /* The checks below are required for ABI consistency with arm */ > - if ((u32)ts >= TASK_SIZE_32) > + if ((u32)ts > UINTPTR_MAX - sizeof(*ts) + 1) > return -EFAULT; > > return __cvdso_clock_gettime32(clock, ts); I probably miss something but I can't find the TASK_SIZE check in the arch/arm/vdso/vgettimeofday.c code. Is this done elsewhere? > @@ -22,7 +25,7 @@ int __vdso_clock_gettime64(clockid_t clock, > struct __kernel_timespec *ts) > { > /* The checks below are required for ABI consistency with arm */ > - if ((u32)ts >= TASK_SIZE_32) > + if ((u32)ts > UINTPTR_MAX - sizeof(*ts) + 1) > return -EFAULT; > > return __cvdso_clock_gettime(clock, ts); > @@ -38,9 +41,12 @@ int __vdso_clock_getres(clockid_t clock_id, > struct old_timespec32 *res) > { > /* The checks below are required for ABI consistency with arm */ > - if ((u32)res >= TASK_SIZE_32) > + if ((u32)res > UINTPTR_MAX - sizeof(res) + 1) > return -EFAULT; > > + if (!VALID_CLOCK_ID(clock_id) && res == NULL) > + return -EINVAL; This last check needs an explanation. If the clock_id is invalid but res is not NULL, we allow it. I don't see where the compatibility issue is, arm32 doesn't have such check. -- Catalin