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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 11B57C49EB7 for ; Mon, 28 Jun 2021 14:20:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F359161C76 for ; Mon, 28 Jun 2021 14:20:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233131AbhF1OWm (ORCPT ); Mon, 28 Jun 2021 10:22:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:55252 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233313AbhF1OV6 (ORCPT ); Mon, 28 Jun 2021 10:21:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AF54E61C83; Mon, 28 Jun 2021 14:19:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624889966; bh=MsshXwOVTdMZveGiqYEW42xX7VKhpFkIC19Vl47loLs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=l0uSQfK80xNu3hotEaxqdVwrNiXu4q8w379W4F8cVaDEK4i+AlcCVb4tVP4MdM9vq 29XCgwF/U/k1pWxgh+MS79/qG5J7bXs5rlQQJUkwfnoBq9U9kmmErt60qKnDiRozlJ 9s0EsHTTqiYvGHBXAj0CCz/yI7yR6hc90jnoeITDCm1k8SRDoO3TEsnwq0ODhX/Hz/ PDPST4wIrAL/M3KF/7J14rJJQuqkTmGAG94RpeH92hTLATo/kQ60MeIk27LmKG0VPE /gklFbDGtqAEJrj1k1Vetd5TEBcRd5TTrR2XGJTFIdvFEES7ePL/3ZR8gzCbOK/BiD ptq+OjPIdMnNg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Heikki Krogerus , Dominik Brodowski , Andy Shevchenko , "Rafael J . Wysocki" , Sasha Levin Subject: [PATCH 5.12 067/110] software node: Handle software node injection to an existing device properly Date: Mon, 28 Jun 2021 10:17:45 -0400 Message-Id: <20210628141828.31757-68-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210628141828.31757-1-sashal@kernel.org> References: <20210628141828.31757-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.12.14-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-5.12.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 5.12.14-rc1 X-KernelTest-Deadline: 2021-06-30T14:18+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Heikki Krogerus [ Upstream commit 5dca69e26fe97f17d4a6cbd6872103c868577b14 ] The function software_node_notify() - the function that creates and removes the symlinks between the node and the device - was called unconditionally in device_add_software_node() and device_remove_software_node(), but it needs to be called in those functions only in the special case where the node is added to a device that has already been registered. This fixes NULL pointer dereference that happens if device_remove_software_node() is used with device that was never registered. Fixes: b622b24519f5 ("software node: Allow node addition to already existing device") Reported-and-tested-by: Dominik Brodowski Reviewed-by: Andy Shevchenko Signed-off-by: Heikki Krogerus Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/base/swnode.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c index 88310ac9ce90..62c536f9d925 100644 --- a/drivers/base/swnode.c +++ b/drivers/base/swnode.c @@ -1032,7 +1032,15 @@ int device_add_software_node(struct device *dev, const struct software_node *nod } set_secondary_fwnode(dev, &swnode->fwnode); - software_node_notify(dev, KOBJ_ADD); + + /* + * If the device has been fully registered by the time this function is + * called, software_node_notify() must be called separately so that the + * symlinks get created and the reference count of the node is kept in + * balance. + */ + if (device_is_registered(dev)) + software_node_notify(dev, KOBJ_ADD); return 0; } @@ -1052,7 +1060,8 @@ void device_remove_software_node(struct device *dev) if (!swnode) return; - software_node_notify(dev, KOBJ_REMOVE); + if (device_is_registered(dev)) + software_node_notify(dev, KOBJ_REMOVE); set_secondary_fwnode(dev, NULL); kobject_put(&swnode->kobj); } @@ -1106,8 +1115,7 @@ int software_node_notify(struct device *dev, unsigned long action) switch (action) { case KOBJ_ADD: - ret = sysfs_create_link_nowarn(&dev->kobj, &swnode->kobj, - "software_node"); + ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node"); if (ret) break; -- 2.30.2