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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FFBECE7A81 for ; Sat, 23 Sep 2023 00:47:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230481AbjIWAru (ORCPT ); Fri, 22 Sep 2023 20:47:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230432AbjIWArs (ORCPT ); Fri, 22 Sep 2023 20:47:48 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7AFC8C6 for ; Fri, 22 Sep 2023 17:46:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1695430015; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=lFq6zMaaGytyLVjCRlM3YGZB/pczKiOV+8u9ckMtHlE=; b=G3vrTVVC1of69IpxZZuPPqUi+P5WnXPwduI0eWjoclZyr0X+S5ZU9zgV7vvtFAop58koAq LfyPQ//gY1F+PcbHfwfZm6hHVP42zwuP25aDSm3ET9r5yv6/g/7I8euN2wnMxPw9XHThUG N3om5xZRRnKAN/q7UY9KsdLllkyPKpQ= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-82-UHzJRoO2NxSdEjhQPdTCeg-1; Fri, 22 Sep 2023 20:46:52 -0400 X-MC-Unique: UHzJRoO2NxSdEjhQPdTCeg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 9CC3185A5BA; Sat, 23 Sep 2023 00:46:51 +0000 (UTC) Received: from localhost (unknown [10.72.112.18]) by smtp.corp.redhat.com (Postfix) with ESMTPS id DB10928FB; Sat, 23 Sep 2023 00:46:50 +0000 (UTC) Date: Sat, 23 Sep 2023 08:46:47 +0800 From: Baoquan He To: Kees Cook Cc: Eric Biederman , kexec@lists.infradead.org, Vivek Goyal , Dave Young , Nathan Chancellor , Nick Desaulniers , Tom Rix , linux-kernel@vger.kernel.org, llvm@lists.linux.dev, linux-hardening@vger.kernel.org Subject: Re: [PATCH] kexec: Annotate struct crash_mem with __counted_by Message-ID: References: <20230922175224.work.712-kees@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230922175224.work.712-kees@kernel.org> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/22/23 at 10:52am, Kees Cook wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > As found with Coccinelle[1], add __counted_by for struct crash_mem. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > > Cc: Eric Biederman > Cc: kexec@lists.infradead.org > Signed-off-by: Kees Cook > --- > include/linux/crash_core.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h > index 3426f6eef60b..5126a4fecb44 100644 > --- a/include/linux/crash_core.h > +++ b/include/linux/crash_core.h > @@ -131,7 +131,7 @@ static inline void __init reserve_crashkernel_generic(char *cmdline, > struct crash_mem { > unsigned int max_nr_ranges; > unsigned int nr_ranges; > - struct range ranges[]; > + struct range ranges[] __counted_by(max_nr_ranges); This __counted_by() only makes sense when there's a obvious upper boundary, max_nr_ranges in this case. This heavily depends and isn't much in kernel? E.g struct swap_info_struct->avail_lists[]. Just curious, not related to this patch though. > }; > > extern int crash_exclude_mem_range(struct crash_mem *mem, > -- > 2.34.1 >