From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-03.galae.net (smtpout-03.galae.net [185.246.85.4]) (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 D3C6A3C07A for ; Mon, 12 Oct 2026 14:30:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.246.85.4 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791815417; cv=none; b=ucZiPfF812UiMN6ooIYueYegVVcbouSbPpMgS0X1QJcHQr5QojWVp2NN8MVhXBqqFlFBut9jFfHpaR07Fsb35qc6ea3gTtk2+aefx44MHzuSlAJpzgzBdb8uAcBXt+iIi7r1rA4zDIyAmDkgoUI9m8uMfPdBs6bj5SLAW3+HWZU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791815417; c=relaxed/simple; bh=Bwpuvl8v0DRrGDDmnSEGPwnGjwFO+duZvJ5OSkkepIA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KAqKwaVXKoMa/6WNTg6O64AEWvOIhwYOSc4G/rlRrLiqoBqoaKf/WV/qKCu93Fi6Stuh2oxoshpv3db4cLiW7VYW0sHsINc/+rcuukuD+DSlwBZH8+Q6Bi7AVQj761AYB06xvGtlMXEScNsNdJh+kVxFPN/DgSdx9vDQHvRkDpY= 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=fpb1hr7N; arc=none smtp.client-ip=185.246.85.4 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="fpb1hr7N" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-03.galae.net (Postfix) with ESMTPS id 649D54E411FB; Mon, 12 Oct 2026 14:30:14 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 35FCE60362; Mon, 12 Oct 2026 14:30:14 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 8AD4311D70C51; Mon, 12 Oct 2026 16:30:01 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1791815406; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding:in-reply-to:references; bh=wTOKh4nIHZqwf3cVaUyxYykTracYnxATB6MngAZuVpg=; b=fpb1hr7N5FKf3AOacO3sWQY50VoGoTDhl6XpnKKsP+N1rNJotDlAPkYvS3EojucBZrQl47 LKo/RdgnHDpPCd61+sArj1yjY1AG5Ga+Qi91iP58KeVsu8hTonC2HIJb7HHEsBUir94q5u syxDSRK0G2G1aEDFqq9JS9KpaaRsudPoCtZRGWIMs2FWRAEpMbMIvw8vzOcPpTZ7bmwGHt oZCaR1FYf4/HcsY+8c7mrY4at31g372EjjutdfQNHUad60a2K6NB0hZt2s4MmA+CSZ/YIo WNWq6sdkOUpTTV05aXt0HUO+PFTQ+STdMpOw0sQWHvFE5FDZJXFIIHG+44p7JA== 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 v13 10/10] PCI: of: Avoid np->data usage for the node changeset Date: Mon, 12 Oct 2026 16:28:24 +0200 Message-ID: <20261012142826.159178-11-herve.codina@bootlin.com> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20261012142826.159178-1-herve.codina@bootlin.com> References: <20261012142826.159178-1-herve.codina@bootlin.com> Precedence: bulk X-Mailing-List: driver-core@lists.linux.dev 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 | 32 ++++++++++++++++++++------------ include/linux/pci.h | 11 +++++++++++ 2 files changed, 31 insertions(+), 12 deletions(-) diff --git a/drivers/pci/of.c b/drivers/pci/of.c index 0a5797652e18..fbed24a244d0 100644 --- a/drivers/pci/of.c +++ b/drivers/pci/of.c @@ -732,15 +732,20 @@ void of_pci_remove_node(struct pci_dev *pdev) { struct device_node *np; + if (!pdev->cset) + return; + np = pci_device_to_OF_node(pdev); - if (!np || !of_node_check_flag(np, OF_DYNAMIC)) + if (!np) return; 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); + pdev->cset = NULL; } void of_pci_make_dev_node(struct pci_dev *pdev) @@ -800,18 +805,17 @@ 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 +832,21 @@ void of_pci_remove_host_bridge_node(struct pci_host_bridge *bridge) { struct device_node *np; + if (!bridge->cset) + return; + np = pci_bus_to_OF_node(bridge->bus); - if (!np || !of_node_check_flag(np, OF_DYNAMIC)) + if (!np) return; 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); + bridge->cset = NULL; } void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge) @@ -899,8 +908,6 @@ 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 +917,8 @@ 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 +926,6 @@ 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