From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-02.galae.net (smtpout-02.galae.net [185.246.84.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96A3C46D096; Wed, 9 Sep 2026 08:02:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.84.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788940975; cv=none; b=Lu+vHhjco97EJRb7pNpyhXUyTbMhMMRaVC2SGufmkOWI5izSAGtV2qtoO6uBqDvBL2+Y8YxMioobYvZaSE4rAKVUTIiMnZBTWtL1MDpJzWLUKIfvt5mPMjEidN9sD/zxA5+IvIieTxCntIjc+M8sp6D1C5rOAwzvlSICrfVryZE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788940975; c=relaxed/simple; bh=AZf0hTGanZoBX9juw8A4Hkcbr/03el49J34+Wj833zM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=FifWWQNUZkWtT8pCgYUuPWvzO8xArNDqRuhlYTI122H9PHQJJlYKS2oiQHeEbckxo/T5jxN0qvRRioYPgambN9Tiyou1x9V3grJkD9tMcBd6IEAlju7zwoivICM8CrAAG+IdvFNFy4URdzWEhsfeZaQ0irFuIgfTuGC437AU6bE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=RIraTNUr; arc=none smtp.client-ip=185.246.84.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="RIraTNUr" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-02.galae.net (Postfix) with ESMTPS id 36D9D1A1A70; Wed, 9 Sep 2026 08:02:51 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 0732F60448; Wed, 9 Sep 2026 08:02:51 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id A0BF711C7AF61; Wed, 9 Sep 2026 10:02:41 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1788940966; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding:in-reply-to:references; bh=eCEDZNLNxkg3C8C9bAECCcFaN+XP6VaQ0+RYJcLH1V4=; b=RIraTNUrkx8rCgnGMdZIZgTAmId6aTvpFsKskmRr8sg58vyK+nsLZw+IEBJ/WApunHb/X8 kXXLsF/GCIY7yWlgLuQ1dLYx4qDXo5z3PainBnBqpGjZC9r4sZaUYSm9alaRpm+2RmlaRu lKFOoY5Th4hY02UleIwruKfgCzgUmV1nVSlZKkfIl9QtoePCzkCWZm7RUh9AmyxjdQiCA8 zNiQeW4LbncfeogkF85WKGhEA/Nmw/TYjgjiPeocqbZ2x3VGbN+6v/R1FLYbIfVXdS3vC/ buGYg/XJLb2IJBYAkx0Xzv0C1QpqFxMk5hvR/nMdJ4e0Ab6CGDzrnrHm8i3Kmg== From: Herve Codina To: Richard Cheng , Andrew Lunn , Rob Herring , Saravana Kannan , Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Bjorn Helgaas , Charles Keepax , Richard Fitzgerald , David Rhodes , Linus Walleij , Andy Shevchenko , Daniel Scally , Heikki Krogerus , Sakari Ailus , Bartosz Golaszewski , Len Brown , Davidlohr Bueso , Jonathan Cameron , Dave Jiang , Alison Schofield , Vishal Verma , Dan Williams , Ira Weiny , Li Ming , Herve Codina , Lizhi Hou Cc: driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, patches@opensource.cirrus.com, linux-gpio@vger.kernel.org, linux-acpi@vger.kernel.org, linux-cxl@vger.kernel.org, Allan Nielsen , Horatiu Vultur , Daniel Machon , Steen Hegelund , Luca Ceresoli , Thomas Petazzoni , stable+noautosel@kernel.org Subject: [PATCH v11 10/10] PCI: of: Avoid np->data usage for the node changeset Date: Wed, 9 Sep 2026 10:01:09 +0200 Message-ID: <20260909080114.591938-11-herve.codina@bootlin.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260909080114.591938-1-herve.codina@bootlin.com> References: <20260909080114.591938-1-herve.codina@bootlin.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 of_pci_remove_node() and of_pci_remove_host_bridge_node() check whether the node is dynamic but not whether it has valid private data. During the node creation, an OF changeset is used and this changeset is stored in np->data to be available for removal functions. If, for instance, a PCI host bridge is created using a device-tree overlay, the related node will have the dynamic flag set but np->data will be NULL. This leads to NULL pointer dereferences. Checking for a non-NULL np->data pointer to determine if the node has been created by the PCI node creation process is not enough. Indeed, on some platforms like PowerPC, the OF_RECONFIG_ATTACH_NODE notifier (e.g., in the pci_dn_reconfig_notifier() function) intercepts node additions and populates np->data with its own structure, such as a struct pci_dn. In that case, np->data is not NULL but it is not related to our changeset stored during the PCI node process creation. Avoid the usage of np->data to store the changeset used during the PCI node creation. Store our changeset in a more relevant structure: either struct pci_dev when the node is created for a PCI device or struct pci_host_bridge when the node is created for the PCI host bridge. With that done, no ambiguity remains on removal. Indeed, this changeset, if non-NULL, is the one used during PCI node creation. Check and use this changeset on the removal process. Fixes: 407d1a51921e ("PCI: Create device tree node for bridge") Fixes: 1f340724419e ("PCI: of: Create device tree PCI host bridge node") Cc: # Issue not triggered but could be a problem Signed-off-by: Herve Codina --- drivers/pci/of.c | 28 ++++++++++++++-------------- include/linux/pci.h | 11 +++++++++++ 2 files changed, 25 insertions(+), 14 deletions(-) diff --git a/drivers/pci/of.c b/drivers/pci/of.c index 0a5797652e18..cd87128c71dd 100644 --- a/drivers/pci/of.c +++ b/drivers/pci/of.c @@ -732,15 +732,16 @@ void of_pci_remove_node(struct pci_dev *pdev) { struct device_node *np; - np = pci_device_to_OF_node(pdev); - if (!np || !of_node_check_flag(np, OF_DYNAMIC)) + if (!pdev->cset) return; + np = pci_device_to_OF_node(pdev); fw_devlink_set_device(&np->fwnode, NULL); device_remove_of_node(&pdev->dev); - of_changeset_revert(np->data); - of_changeset_destroy(np->data); + of_changeset_revert(pdev->cset); + of_changeset_destroy(pdev->cset); of_node_put(np); + kfree(pdev->cset); } void of_pci_make_dev_node(struct pci_dev *pdev) @@ -800,18 +801,17 @@ void of_pci_make_dev_node(struct pci_dev *pdev) if (ret) goto out_clear_devlink_dev; - np->data = cset; - ret = device_add_of_node(&pdev->dev, np); if (ret) goto out_revert_cset; + pdev->cset = cset; + kfree(name); return; out_revert_cset: - np->data = NULL; of_changeset_revert(cset); out_clear_devlink_dev: fw_devlink_set_device(&np->fwnode, NULL); @@ -828,16 +828,17 @@ void of_pci_remove_host_bridge_node(struct pci_host_bridge *bridge) { struct device_node *np; - np = pci_bus_to_OF_node(bridge->bus); - if (!np || !of_node_check_flag(np, OF_DYNAMIC)) + if (!bridge->cset) return; + np = pci_bus_to_OF_node(bridge->bus); fw_devlink_set_device(&np->fwnode, NULL); device_remove_of_node(&bridge->bus->dev); device_remove_of_node(&bridge->dev); - of_changeset_revert(np->data); - of_changeset_destroy(np->data); + of_changeset_revert(bridge->cset); + of_changeset_destroy(bridge->cset); of_node_put(np); + kfree(bridge->cset); } void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge) @@ -899,8 +900,6 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge) if (ret) goto out_clear_devlink_dev; - np->data = cset; - /* Add the of_node to host bridge and the root bus */ ret = device_add_of_node(&bridge->dev, np); if (ret) @@ -910,6 +909,8 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge) if (ret) goto out_remove_bridge_dev_of_node; + bridge->cset = cset; + kfree(name); return; @@ -917,7 +918,6 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge) out_remove_bridge_dev_of_node: device_remove_of_node(&bridge->dev); out_revert_cset: - np->data = NULL; of_changeset_revert(cset); out_clear_devlink_dev: fw_devlink_set_device(&np->fwnode, NULL); diff --git a/include/linux/pci.h b/include/linux/pci.h index d31a8d107b1e..7b0ba9ec7b5c 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -339,6 +339,9 @@ struct pcie_link_state; struct pci_sriov; struct pci_p2pdma; struct rcec_ea; +#ifdef CONFIG_PCI_DYNAMIC_OF_NODES +struct of_changeset; +#endif /* struct pci_dev - describes a PCI device * @@ -598,6 +601,10 @@ struct pci_dev { u8 tph_mode; /* TPH mode */ u8 tph_req_type; /* TPH requester type */ #endif + +#ifdef CONFIG_PCI_DYNAMIC_OF_NODES + struct of_changeset *cset; /* Changeset used for OF node creation */ +#endif }; static inline struct pci_dev *pci_physfn(struct pci_dev *dev) @@ -670,6 +677,10 @@ struct pci_host_bridge { unsigned int broken_l1ss_resume:1; /* Resuming from L1SS during system suspend is broken */ +#ifdef CONFIG_PCI_DYNAMIC_OF_NODES + struct of_changeset *cset; /* Changeset used for OF node creation */ +#endif + /* Resource alignment requirements */ resource_size_t (*align_resource)(struct pci_dev *dev, const struct resource *res, -- 2.55.0