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[2620:137:e000::1:20]) by mx.google.com with ESMTP id ci23-20020a17090afc9700b0023b30b28b89si13600964pjb.56.2023.04.18.07.01.03; Tue, 18 Apr 2023 07:01:16 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linuxfoundation.org header.s=korg header.b=Q6a4v5FL; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linuxfoundation.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232422AbjDRNra (ORCPT + 99 others); Tue, 18 Apr 2023 09:47:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232186AbjDRNr1 (ORCPT ); Tue, 18 Apr 2023 09:47:27 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 150AB125A7 for ; Tue, 18 Apr 2023 06:47:23 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 90485634FE for ; Tue, 18 Apr 2023 13:47:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9A865C433D2; Tue, 18 Apr 2023 13:47:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681825643; bh=z6bziQOWX6ta9DQwSmPL8i4kjhV1G33KL8lW3/ZwuFI=; h=From:To:Cc:Subject:Date:From; b=Q6a4v5FL00efHxA4dSrTnY11Mr7uWQQ3zWozDGeBV/BMl0k/4g44m2DLZw4yLXZMF mBg7NOG36iinQwKs4FCgsvuvfwM/EwvI69DfxRJPrObEXitg+67yAmqb6n7MoRgehf E3k6KI5SqUhK+xaI88prLAG6jrVNj4qmqxE3cwhM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Denis Efremov Subject: [PATCH] zram: fix up permission for the hot_add sysfs file Date: Tue, 18 Apr 2023 15:47:15 +0200 Message-Id: <2023041810-angelic-conical-52d8@gregkh> X-Mailer: git-send-email 2.40.0 MIME-Version: 1.0 Lines: 35 X-Developer-Signature: v=1; a=openpgp-sha256; l=1491; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=z6bziQOWX6ta9DQwSmPL8i4kjhV1G33KL8lW3/ZwuFI=; b=owGbwMvMwCRo6H6F97bub03G02pJDCl28+O8H6QZ/89wj/mgnlT27tnVL3zJXOxeNfdmGb6bu EiVrWN3RywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzkqy/D/Irtk97nnzTa8MjI yijjfFjNJOab8xnmB8ea+jevmFpyd2eezbN958M1dzFKAwA= X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 X-Spam-Status: No, score=-7.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_HI, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1763522879670731875?= X-GMAIL-MSGID: =?utf-8?q?1763522879670731875?= Commit 75a2d4226b53 ("driver core: class: mark the struct class for sysfs callbacks as constant") changed the attribute to use CLASS_ATTR_RO() which changed the permission from 0400 to 0444. But this atribute is "special" in that reading it modifies the system state, so it MUST be set to 0400 so that only root processes can muck around with it. Fix this all up, AND document this so that I don't change it again in 3-4 years when I stumble across it and wonder why it's an open-coded _ATTR() macro. Reported-by: Denis Efremov Fixes: 75a2d4226b53 ("driver core: class: mark the struct class for sysfs callbacks as constant") Signed-off-by: Greg Kroah-Hartman --- drivers/block/zram/zram_drv.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c index 3feadfb96114..d8217529be6f 100644 --- a/drivers/block/zram/zram_drv.c +++ b/drivers/block/zram/zram_drv.c @@ -2438,7 +2438,9 @@ static ssize_t hot_add_show(const struct class *class, return ret; return scnprintf(buf, PAGE_SIZE, "%d\n", ret); } -static CLASS_ATTR_RO(hot_add); +/* This attribute must be set to 0400, so CLASS_ATTR_RO() can not be used */ +static struct class_attribute class_attr_hot_add = + __ATTR(hot_add, 0400, hot_add_show, NULL); static ssize_t hot_remove_store(const struct class *class, const struct class_attribute *attr,