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 C7779C433F5 for ; Tue, 5 Apr 2022 07:44:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229905AbiDEHp4 (ORCPT ); Tue, 5 Apr 2022 03:45:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231985AbiDEHpf (ORCPT ); Tue, 5 Apr 2022 03:45:35 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D7FBE92D2C; Tue, 5 Apr 2022 00:41:24 -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 7E46BB81B75; Tue, 5 Apr 2022 07:41:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C77B9C340EE; Tue, 5 Apr 2022 07:41:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649144482; bh=u8cclAT3USm2ckXvRzJKzZhIhuNCejG+lU+PnBp3YA8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ev6EWY1UZyhYdqeVt2j+Fy/JGjZ4OnhsJ88Fzzvag7RbmLuD0KngHmbVmrouebECq 0za+Ia1KTc8UBzholJ8cfiIkYcCFlBjOnu74xbda60i6qZOMvxR+1xGNQt9FdBbAv5 y1jfUNqiJitb00Jdf9hSY+8NuLH3fuVyKf97aOD8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Usyskin , Tomas Winkler Subject: [PATCH 5.17 0021/1126] mei: avoid iterator usage outside of list_for_each_entry Date: Tue, 5 Apr 2022 09:12:48 +0200 Message-Id: <20220405070408.167043842@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070407.513532867@linuxfoundation.org> References: <20220405070407.513532867@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Alexander Usyskin commit c10187b1c5ebb8681ca467ab7b0ded5ea415d258 upstream. Usage of the iterator outside of the list_for_each_entry is considered harmful. https://lkml.org/lkml/2022/2/17/1032 Do not reference the loop variable outside of the loop, by rearranging the orders of execution. Instead of performing search loop and checking outside the loop if the end of the list was hit and no matching element was found, the execution is performed inside the loop upon a successful match followed by a goto statement to the next step, therefore no condition has to be performed after the loop has ended. Cc: Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Link: https://lore.kernel.org/r/20220308095926.300412-1-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/interrupt.c | 35 +++++++++++++++-------------------- 1 file changed, 15 insertions(+), 20 deletions(-) --- a/drivers/misc/mei/interrupt.c +++ b/drivers/misc/mei/interrupt.c @@ -424,31 +424,26 @@ int mei_irq_read_handler(struct mei_devi list_for_each_entry(cl, &dev->file_list, link) { if (mei_cl_hbm_equal(cl, mei_hdr)) { cl_dbg(dev, cl, "got a message\n"); - break; + ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list); + goto reset_slots; } } /* if no recipient cl was found we assume corrupted header */ - if (&cl->link == &dev->file_list) { - /* A message for not connected fixed address clients - * should be silently discarded - * On power down client may be force cleaned, - * silently discard such messages - */ - if (hdr_is_fixed(mei_hdr) || - dev->dev_state == MEI_DEV_POWER_DOWN) { - mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length); - ret = 0; - goto reset_slots; - } - dev_err(dev->dev, "no destination client found 0x%08X\n", - dev->rd_msg_hdr[0]); - ret = -EBADMSG; - goto end; + /* A message for not connected fixed address clients + * should be silently discarded + * On power down client may be force cleaned, + * silently discard such messages + */ + if (hdr_is_fixed(mei_hdr) || + dev->dev_state == MEI_DEV_POWER_DOWN) { + mei_irq_discard_msg(dev, mei_hdr, mei_hdr->length); + ret = 0; + goto reset_slots; } - - ret = mei_cl_irq_read_msg(cl, mei_hdr, meta_hdr, cmpl_list); - + dev_err(dev->dev, "no destination client found 0x%08X\n", dev->rd_msg_hdr[0]); + ret = -EBADMSG; + goto end; reset_slots: /* reset the number of slots and header */