From patchwork Thu Sep 22 04:28:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 608557 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 F0D48C6FA82 for ; Thu, 22 Sep 2022 04:28:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230402AbiIVE2p (ORCPT ); Thu, 22 Sep 2022 00:28:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46766 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231140AbiIVE2o (ORCPT ); Thu, 22 Sep 2022 00:28:44 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0EBB3AE9CA; Wed, 21 Sep 2022 21:28:43 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9552AB829F9; Thu, 22 Sep 2022 04:28:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D8C2C433C1; Thu, 22 Sep 2022 04:28:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663820920; bh=tWSCYk4ZSoVou22LxOw2uWNE5Vi+oMt7ylUBlRbR7Vk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hBRq4D7ZWG6gaSv+DdtCbgetQCTL3WCmZYc68VNK01Q7CkzWY5CnYCHXOIsesBKuO 9kWPIbFrDfWVEz2GorlkBZto9rDSTYjWNyGO1KKl9ayS6YXWKiMIsoc1U+kayIeZfK 4008LBsO4fkvC3coQ9cByPactT6conJdSWBtMzxmKYll4rnmnkGd/+7hGPAFU9GRww JDroPHGRqp51LOtMuVJWgm1ZLoHw9dGDELkd2kg5ifpIphDjvoO3dm7V7F8bDOMex9 3ukfCqVKXnr6JhDF6QP9Bkodw+Fz7ggHgMQstl7UgZiT5ERbPKoQZcZmcnbXhaC4oJ 7zpVe6Zw/o7pQ== Date: Wed, 21 Sep 2022 23:28:35 -0500 From: "Gustavo A. R. Silva" To: Kevin Barnett , Don Brace , storagedev@microchip.com, "James E.J. Bottomley" , "Martin K. Petersen" Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH 1/3][next] scsi: smartpqi: Replace one-element array with flexible-array member Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org One-element arrays are deprecated, and we are replacing them with flexible array members instead. So, replace one-element array with flexible-array member in struct MR_DRV_RAID_MAP and refactor the the rest of the code accordingly. It seems that the addition of sizeof(struct report_log_lun) in all the places that are modified by this patch is due to the fact that the one-element array struct report_log_lun lun_entries[1]; always contributes to the size of the containing structure struct report_log_lun_list. Notice that at line 1267 while allocating memory for an instance of struct report_log_lun_list, some _extra_ space seems to be allocated for one element of type struct report_log_lun, which is the type of the elements in array lun_entries: 1267 internal_logdev_list = kmalloc(logdev_data_length + 1268 sizeof(struct report_log_lun), GFP_KERNEL); However, at line 1275 just logdev_data_length bytes are copied into internal_logdev_list (remember that we allocated space for logdev_data_length + sizeof(struct report_log_lun) bytes at line 1267), and then exactly sizeof(struct report_log_lun) bytes are being zeroing out at line 1276. 1275 memcpy(internal_logdev_list, logdev_data, logdev_data_length); 1276 memset((u8 *)internal_logdev_list + logdev_data_length, 0, 1277 sizeof(struct report_log_lun)); All the above makes think that it's just fine if we transform array lun_entries into a flexible-array member and just don't allocate that extra sizeof(struct report_log_lun) bytes of space. With this we can remove that memset() call and we also need to modify the code that updates the total length (internal_logdev_list->header.list_length) of array lun_entries at line 1278: 1278 put_unaligned_be32(logdev_list_length + 1279 sizeof(struct report_log_lun), 1280 &internal_logdev_list->header.list_length); This helps with the ongoing efforts to tighten the FORTIFY_SOURCE routines on memcpy(). Link: https://github.com/KSPP/linux/issues/79 Link: https://github.com/KSPP/linux/issues/204 Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook --- And of course, it'd be great if maintainers can confirm what I described in the changelog text. :) drivers/scsi/smartpqi/smartpqi.h | 2 +- drivers/scsi/smartpqi/smartpqi_init.c | 10 +++------- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/smartpqi/smartpqi.h b/drivers/scsi/smartpqi/smartpqi.h index e550b12e525a..d1756c9d1112 100644 --- a/drivers/scsi/smartpqi/smartpqi.h +++ b/drivers/scsi/smartpqi/smartpqi.h @@ -954,7 +954,7 @@ struct report_log_lun { struct report_log_lun_list { struct report_lun_header header; - struct report_log_lun lun_entries[1]; + struct report_log_lun lun_entries[]; }; struct report_phys_lun_8byte_wwid { diff --git a/drivers/scsi/smartpqi/smartpqi_init.c b/drivers/scsi/smartpqi/smartpqi_init.c index b971fbe3b3a1..544cd18a90d7 100644 --- a/drivers/scsi/smartpqi/smartpqi_init.c +++ b/drivers/scsi/smartpqi/smartpqi_init.c @@ -1264,8 +1264,7 @@ static int pqi_get_device_lists(struct pqi_ctrl_info *ctrl_info, logdev_data_length = sizeof(struct report_lun_header) + logdev_list_length; - internal_logdev_list = kmalloc(logdev_data_length + - sizeof(struct report_log_lun), GFP_KERNEL); + internal_logdev_list = kmalloc(logdev_data_length, GFP_KERNEL); if (!internal_logdev_list) { kfree(*logdev_list); *logdev_list = NULL; @@ -1273,11 +1272,8 @@ static int pqi_get_device_lists(struct pqi_ctrl_info *ctrl_info, } memcpy(internal_logdev_list, logdev_data, logdev_data_length); - memset((u8 *)internal_logdev_list + logdev_data_length, 0, - sizeof(struct report_log_lun)); - put_unaligned_be32(logdev_list_length + - sizeof(struct report_log_lun), - &internal_logdev_list->header.list_length); + put_unaligned_be32(logdev_list_length, + &internal_logdev_list->header.list_length); kfree(*logdev_list); *logdev_list = internal_logdev_list;