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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21BA2C3A5A3 for ; Tue, 27 Aug 2019 08:06:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA722206BA for ; Tue, 27 Aug 2019 08:06:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566893183; bh=YjerzujQHNFzHW6x30LYl9x9aky76kArD48zYRFWU9U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zgxAD6eXSppMYZA3CbzFBC0p8F5PAMzzofoiGZOXT09872Yikgaxt+IKZM1UhkHmJ H51IexOBQTAEQb1PfaRcFZLICKm7nZe+FZR8ts0mKVHWpnoP7g7c51o6YsPe8APtRm q9R8g41Uau9wLNZdI9YU7RBcBt5/CP0kmoAO/pWc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733030AbfH0IGV (ORCPT ); Tue, 27 Aug 2019 04:06:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:36302 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731768AbfH0IGS (ORCPT ); Tue, 27 Aug 2019 04:06:18 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 68CC52173E; Tue, 27 Aug 2019 08:06:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566893177; bh=YjerzujQHNFzHW6x30LYl9x9aky76kArD48zYRFWU9U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MGCDW6pvOq4oj2mST1BARBxosYa1XHMCuPgXjiwoUuyL/4I/aIgLO6FNtiRFoLjWJ wY/yQ53TcVj/7KWMiKHmasKJ8lqwVRuV+FGFziV3OE/+Qz6f0jzTy4TaBbencxclaW AkJ1ve6yxzyilUDH808fR81maEUKBoGMQZrBWGaw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Kelley , Thomas Gleixner Subject: [PATCH 5.2 145/162] genirq: Properly pair kobject_del() with kobject_add() Date: Tue, 27 Aug 2019 09:51:13 +0200 Message-Id: <20190827072743.753109574@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190827072738.093683223@linuxfoundation.org> References: <20190827072738.093683223@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Kelley commit d0ff14fdc987303aeeb7de6f1bd72c3749ae2a9b upstream. If alloc_descs() fails before irq_sysfs_init() has run, free_desc() in the cleanup path will call kobject_del() even though the kobject has not been added with kobject_add(). Fix this by making the call to kobject_del() conditional on whether irq_sysfs_init() has run. This problem surfaced because commit aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") makes kobject_del() stricter about pairing with kobject_add(). If the pairing is incorrrect, a WARNING and backtrace occur in sysfs_remove_group() because there is no parent. [ tglx: Add a comment to the code and make it work with CONFIG_SYSFS=n ] Fixes: ecb3f394c5db ("genirq: Expose interrupt information through sysfs") Signed-off-by: Michael Kelley Signed-off-by: Thomas Gleixner Acked-by: Greg Kroah-Hartman Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1564703564-4116-1-git-send-email-mikelley@microsoft.com Signed-off-by: Greg Kroah-Hartman --- kernel/irq/irqdesc.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -295,6 +295,18 @@ static void irq_sysfs_add(int irq, struc } } +static void irq_sysfs_del(struct irq_desc *desc) +{ + /* + * If irq_sysfs_init() has not yet been invoked (early boot), then + * irq_kobj_base is NULL and the descriptor was never added. + * kobject_del() complains about a object with no parent, so make + * it conditional. + */ + if (irq_kobj_base) + kobject_del(&desc->kobj); +} + static int __init irq_sysfs_init(void) { struct irq_desc *desc; @@ -325,6 +337,7 @@ static struct kobj_type irq_kobj_type = }; static void irq_sysfs_add(int irq, struct irq_desc *desc) {} +static void irq_sysfs_del(struct irq_desc *desc) {} #endif /* CONFIG_SYSFS */ @@ -438,7 +451,7 @@ static void free_desc(unsigned int irq) * The sysfs entry must be serialized against a concurrent * irq_sysfs_init() as well. */ - kobject_del(&desc->kobj); + irq_sysfs_del(desc); delete_irq_desc(irq); /*