From patchwork Tue Sep 26 09:27:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Hans Verkuil X-Patchwork-Id: 726619 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 26FF0E7D26E for ; Tue, 26 Sep 2023 09:27:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234201AbjIZJ1l (ORCPT ); Tue, 26 Sep 2023 05:27:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43052 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234302AbjIZJ10 (ORCPT ); Tue, 26 Sep 2023 05:27:26 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 925F7CD9 for ; Tue, 26 Sep 2023 02:27:12 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 953E9C433C9; Tue, 26 Sep 2023 09:27:11 +0000 (UTC) Message-ID: Date: Tue, 26 Sep 2023 11:27:09 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US, nl To: Hans de Goede Cc: Linux Media Mailing List From: Hans Verkuil Subject: [PATCH] media: atomisp: fix 'read beyond size of field' Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org If CONFIG_FORTIFY_SOURCE=y, then this warning is produced: In file included from ./include/linux/string.h:254, from ./include/linux/bitmap.h:11, from ./include/linux/cpumask.h:12, from ./arch/x86/include/asm/cpumask.h:5, from ./arch/x86/include/asm/msr.h:11, from ./arch/x86/include/asm/processor.h:23, from ./arch/x86/include/asm/cpufeature.h:5, from ./arch/x86/include/asm/thread_info.h:53, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:9, from ./include/linux/preempt.h:79, from ./include/linux/spinlock.h:56, from ./include/linux/mmzone.h:8, from ./include/linux/gfp.h:7, from ./include/linux/slab.h:16, from ./drivers/staging/media/atomisp//include/hmm/hmm.h:26, from drivers/staging/media/atomisp/pci/sh_css_params.c:26: In function ‘fortify_memcpy_chk’, inlined from ‘sh_css_store_sp_group_to_ddr’ at drivers/staging/media/atomisp/pci/sh_css_params.c:3736:3: ./include/linux/fortify-string.h:592:25: warning: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 592 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The reason is that the memcpy copies two fields (each a u8), when the source pointer points to the first field. It's a bit unexpected, so just make this explicit. Signed-off-by: Hans Verkuil --- Hans, can you verify that it is indeed the intention of the original code to write both bytes? Note that I think that the initial memcpy is equally dubious. I think that should be replaced by '*buf_ptr++ = ...' lines as well, rather than just copying the first three fields with a memcpy. If you want I can make a v2 that does that. --- diff --git a/drivers/staging/media/atomisp/pci/sh_css_params.c b/drivers/staging/media/atomisp/pci/sh_css_params.c index 5667e855da76..232744973ab8 100644 --- a/drivers/staging/media/atomisp/pci/sh_css_params.c +++ b/drivers/staging/media/atomisp/pci/sh_css_params.c @@ -3733,8 +3733,8 @@ ia_css_ptr sh_css_store_sp_group_to_ddr(void) if (IS_ISP2401) { memcpy(buf_ptr, &sh_css_sp_group.config, 3); buf_ptr += 3; - memcpy(buf_ptr, &sh_css_sp_group.config.enable_isys_event_queue, 2); - buf_ptr += 2; + *buf_ptr++ = sh_css_sp_group.config.enable_isys_event_queue; + *buf_ptr++ = sh_css_sp_group.config.disable_cont_vf; memset(buf_ptr, 0, 3); buf_ptr += 3; /* Padding 3 bytes for struct sh_css_sp_config*/ } else {