[PATCH v13 02/10] drivers: core: Use fw_devlink_set_device()

[PATCH v13 02/10] drivers: core: Use fw_devlink_set_device()

[Herve Codina]

The code set directly fwnode->dev field.

Use the dedicated fw_devlink_set_device() helper to perform this
operation.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/base/core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 4c0c373998a1..3268e9350c86 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -3754,7 +3754,7 @@ int device_add(struct device *dev)
 	 * device and the driver sync_state callback is called for this device.
 	 */
 	if (dev->fwnode && !dev->fwnode->dev) {
-		dev->fwnode->dev = dev;
+		fw_devlink_set_device(dev->fwnode, dev);
 		fw_devlink_link_device(dev);
 	}
 
@@ -3929,7 +3929,7 @@ void device_del(struct device *dev)
 	device_unlock(dev);
 
 	if (dev->fwnode && dev->fwnode->dev == dev)
-		dev->fwnode->dev = NULL;
+		fw_devlink_set_device(dev->fwnode, NULL);
 
 	/* Notify clients of device removal.  This call must come
 	 * before dpm_sysfs_remove().
-- 
2.55.0

Re: [PATCH v13 02/10] drivers: core: Use fw_devlink_set_device()

[sashiko-bot]

> The code set directly fwnode->dev field.
> 
> Use the dedicated fw_devlink_set_device() helper to perform this
> operation.
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=2

[PATCH v13 03/10] pinctrl: cs42l43: Use fw_devlink_set_device()

[Herve Codina]

The code set directly fwnode->dev field.

Use the dedicated fw_devlink_set_device() helper to perform this
operation.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Acked-by: Linus Walleij <linusw@kernel.org>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/pinctrl/cirrus/pinctrl-cs42l43.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pinctrl/cirrus/pinctrl-cs42l43.c b/drivers/pinctrl/cirrus/pinctrl-cs42l43.c
index 8990fab0446c..563070aba3d8 100644
--- a/drivers/pinctrl/cirrus/pinctrl-cs42l43.c
+++ b/drivers/pinctrl/cirrus/pinctrl-cs42l43.c
@@ -576,7 +576,7 @@ static int cs42l43_pin_probe(struct platform_device *pdev)
 				return ret;
 
 			if (!child->dev)
-				child->dev = priv->dev;
+				fw_devlink_set_device(child, priv->dev);
 			fwnode = child;
 		}
 	}
-- 
2.55.0

Re: [PATCH v13 03/10] pinctrl: cs42l43: Use fw_devlink_set_device()

[sashiko-bot]

> The code set directly fwnode->dev field.
> 
> Use the dedicated fw_devlink_set_device() helper to perform this
> operation.
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=3

[PATCH v13 04/10] cxl/test: Use device_set_node()

[Herve Codina]

The code set directly dev->fwnode.

Use the dedicated helper to perform this operation.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 tools/testing/cxl/test/cxl.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 62bd92b3be45..547ebc97bf59 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -1677,7 +1677,7 @@ static void mock_companion(struct acpi_device *adev, struct device *dev)
 {
 	device_initialize(&adev->dev);
 	fwnode_init(&adev->fwnode, NULL);
-	dev->fwnode = &adev->fwnode;
+	device_set_node(dev, &adev->fwnode);
 	adev->fwnode.dev = dev;
 }
 
-- 
2.55.0

Re: [PATCH v13 04/10] cxl/test: Use device_set_node()

[sashiko-bot]

> The code set directly dev->fwnode.
> 
> Use the dedicated helper to perform this operation.
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=4

[PATCH v13 06/10] PCI: of: Use fw_devlink_set_device()

[Herve Codina]

The code set directly fwnode.dev field.

Use the dedicated fw_devlink_set_device() helper to perform this
operation.

Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
Cc stable because used by other patches with Fixes + Cc stable
---
 drivers/pci/of.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index a51dff91b196..0f45c5b72458 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -882,7 +882,7 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge)
 	 * bus. Avoid any new device creation.
 	 */
 	of_node_set_flag(np, OF_POPULATED);
-	np->fwnode.dev = &bridge->dev;
+	fw_devlink_set_device(&np->fwnode, &bridge->dev);
 	fwnode_dev_initialized(&np->fwnode, true);
 
 	ret = of_changeset_apply(cset);
-- 
2.55.0

Re: [PATCH v13 06/10] PCI: of: Use fw_devlink_set_device()

[sashiko-bot]

> The code set directly fwnode.dev field.
> 
> Use the dedicated fw_devlink_set_device() helper to perform this
> operation.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=6

[PATCH v13 07/10] PCI: of: Clear fwnode->dev during root bridge node removal and error path

[Herve Codina]

During the of_pci_make_host_bridge_node() call, an OF node is created
dynamically and its fwnode device (fwnode->dev) is set to the PCI root
bridge device using the fw_devlink_set_device(&np->fwnode, &bridge->dev)
call.

On removal, of_pci_remove_host_bridge_node() is called and calls
device_remove_of_node() which in turn set to NULL the related
dev->fwnode.

Later in the removal sequence, device_del() is called and runs its
cleanup logic:

    if (dev->fwnode && dev->fwnode->dev == dev)
        fw_devlink_set_device(dev->fwnode, NULL);

Because dev->fwnode has been cleared earlier, fw_devlink_set_device()
is not called and leaves fwnode->dev unchanged. This fwnode device
(fwnode->dev) becomes an dangling pointer.

If any reference to the OF node is held after this removal, the pointer
is still accessible using the OF node (np->fwnode.dev) but points to a
freed area.

The exact same issue is present in the of_pci_make_host_bridge_node()
error path leading to the exact same dangling fwnode->dev.

Avoid this dangling fwnode->dev pointer by clearing it in
of_pci_remove_host_bridge_node() and in of_pci_make_host_bridge_node()
error path.

Fixes: 1f340724419e ("PCI: of: Create device tree PCI host bridge node")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/pci/of.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 0f45c5b72458..29b63a9090ae 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -822,6 +822,7 @@ void of_pci_remove_host_bridge_node(struct pci_host_bridge *bridge)
 	if (!np || !of_node_check_flag(np, OF_DYNAMIC))
 		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);
@@ -887,7 +888,7 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge)
 
 	ret = of_changeset_apply(cset);
 	if (ret)
-		goto out_free_node;
+		goto out_clear_devlink_dev;
 
 	np->data = cset;
 
@@ -909,6 +910,8 @@ void of_pci_make_host_bridge_node(struct pci_host_bridge *bridge)
 out_revert_cset:
 	np->data = NULL;
 	of_changeset_revert(cset);
+out_clear_devlink_dev:
+	fw_devlink_set_device(&np->fwnode, NULL);
 out_free_node:
 	of_node_put(np);
 out_destroy_cset:
-- 
2.55.0

Re: [PATCH v13 07/10] PCI: of: Clear fwnode->dev during root bridge node removal and error path

[sashiko-bot]

> During the of_pci_make_host_bridge_node() call, an OF node is created
> dynamically and its fwnode device (fwnode->dev) is set to the PCI root
> bridge device using the fw_devlink_set_device(&np->fwnode, &bridge->dev)
> call.
> 
> On removal, of_pci_remove_host_bridge_node() is called and calls
> device_remove_of_node() which in turn set to NULL the related
> dev->fwnode.
> 
> Later in the removal sequence, device_del() is called and runs its
> cleanup logic:
> 
>     if (dev->fwnode && dev->fwnode->dev == dev)
>         fw_devlink_set_device(dev->fwnode, NULL);
> 
> [ ... ]
> error path.
> 
> Fixes: 1f340724419e ("PCI: of: Create device tree PCI host bridge node")
> Cc: stable@vger.kernel.org
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=7

[PATCH v13 08/10] PCI: of: Set fwnode device of newly created PCI device nodes

[Herve Codina]

Device-tree node can be created when CONFIG_PCI_DYNAMIC_OF_NODES. Those
nodes are created and filled based on PCI core information but the
fwnode device field is not set.

When later an overlay is applied, this confuses fw_devlink. Indeed,
without any device attached to the node, fw_devlink considers that this
node will never become a device. When this node is pointed as a
supplier, devlink looks at its ancestors in order to find a node with a
device that could be used as the supplier.

In the PCI use case, this leads to links that wrongly use the PCI root
bridge device as the supplier instead of the expected PCI device.

Setting the fwnode device to the device of the PCI device allows devlink
to use this device as a supplier and so, correct links are created.

Fixes: 407d1a51921e ("PCI: Create device tree node for bridge")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@oss.qualcomm.com>
---
 drivers/pci/of.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 29b63a9090ae..8914bfa25dc1 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -736,6 +736,7 @@ void of_pci_remove_node(struct pci_dev *pdev)
 	if (!np || !of_node_check_flag(np, OF_DYNAMIC))
 		return;
 
+	fw_devlink_set_device(&np->fwnode, NULL);
 	device_remove_of_node(&pdev->dev);
 	of_changeset_revert(np->data);
 	of_changeset_destroy(np->data);
@@ -788,9 +789,16 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
 	if (ret)
 		goto out_free_node;
 
+	/*
+	 * Set the fwnode device in order to have fw_devlink creating links
+	 * pointing to this PCI device instead of walking up to the PCI host
+	 * bridge.
+	 */
+	fw_devlink_set_device(&np->fwnode, &pdev->dev);
+
 	ret = of_changeset_apply(cset);
 	if (ret)
-		goto out_free_node;
+		goto out_clear_devlink_dev;
 
 	np->data = cset;
 
@@ -805,6 +813,8 @@ void of_pci_make_dev_node(struct pci_dev *pdev)
 out_revert_cset:
 	np->data = NULL;
 	of_changeset_revert(cset);
+out_clear_devlink_dev:
+	fw_devlink_set_device(&np->fwnode, NULL);
 out_free_node:
 	of_node_put(np);
 out_destroy_cset:
-- 
2.55.0

Re: [PATCH v13 08/10] PCI: of: Set fwnode device of newly created PCI device nodes

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] base: TOCTOU data race and UAF on fwnode->dev access
--

commit dc94be607770b564614555ac56ea83f070fa3dd4
Author: Herve Codina <herve.codina@bootlin.com>

PCI: of: Set fwnode device of newly created PCI device nodes

Device-tree node can be created when CONFIG_PCI_DYNAMIC_OF_NODES. Those
nodes are created and filled based on PCI core information but the
fwnode device field is not set.

> diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> index 29b63a9090ae3..8914bfa25dc11 100644
> --- a/drivers/pci/of.c
> +++ b/drivers/pci/of.c
> @@ -736,6 +736,7 @@ void of_pci_remove_node(struct pci_dev *pdev)
>  	if (!np || !of_node_check_flag(np, OF_DYNAMIC))
>  		return;
>  
> +	fw_devlink_set_device(&np->fwnode, NULL);

[Severity: High]
Does this locklessly clear the fwnode device while another traversal might be
reading it?

If a PCI device is concurrently removed while a driver is being bound to
another device on the same system, of_pci_remove_node() clears fwnode->dev
locklessly here.

Concurrently, __fw_devlink_pickup_dangling_consumers() in drivers/base/core.c
can traverse the fwnode tree and read it locklessly:

	if (fwnode->dev && fwnode->dev->bus)
		return;

Can this lead to a NULL pointer dereference if the compiler emits two loads
and the pointer is cleared in between?

Can this also cause a use-after-free if the pointer is read, then the device
is concurrently unregistered and freed before the bus field is accessed, as
no reference count is held during the lockless read?

>  	device_remove_of_node(&pdev->dev);
>  	of_changeset_revert(np->data);
>  	of_changeset_destroy(np->data);

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=8

Re: [PATCH v13 08/10] PCI: of: Set fwnode device of newly created PCI device nodes

[Herve Codina]

On Mon, 12 Oct 2026 14:44:48 +0000
sashiko-bot@kernel.org wrote:

> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [High] base: TOCTOU data race and UAF on fwnode->dev access
> --
> 
> commit dc94be607770b564614555ac56ea83f070fa3dd4
> Author: Herve Codina <herve.codina@bootlin.com>
> 
> PCI: of: Set fwnode device of newly created PCI device nodes
> 
> Device-tree node can be created when CONFIG_PCI_DYNAMIC_OF_NODES. Those
> nodes are created and filled based on PCI core information but the
> fwnode device field is not set.
> 
> > diff --git a/drivers/pci/of.c b/drivers/pci/of.c
> > index 29b63a9090ae3..8914bfa25dc11 100644
> > --- a/drivers/pci/of.c
> > +++ b/drivers/pci/of.c
> > @@ -736,6 +736,7 @@ void of_pci_remove_node(struct pci_dev *pdev)
> >  	if (!np || !of_node_check_flag(np, OF_DYNAMIC))
> >  		return;
> >  
> > +	fw_devlink_set_device(&np->fwnode, NULL);  
> 
> [Severity: High]
> Does this locklessly clear the fwnode device while another traversal might be
> reading it?
> 
> If a PCI device is concurrently removed while a driver is being bound to
> another device on the same system, of_pci_remove_node() clears fwnode->dev
> locklessly here.
> 
> Concurrently, __fw_devlink_pickup_dangling_consumers() in drivers/base/core.c
> can traverse the fwnode tree and read it locklessly:
> 
> 	if (fwnode->dev && fwnode->dev->bus)
> 		return;

I don't think so.

__fw_devlink_pickup_dangling_consumers() can look at fwnode->dev but those
fwnode->dev are not in the same branch in the tree as the one where the fwnode
being modified is located.

I don't see any cases where __fw_devlink_pickup_dangling_consumers() can
reach our fwnode.

In other word I don't see any race condition on my side and so I will not try
to fix that point except if this "potential" issue is confirmed by other people.
Indeed, I could be wrong in my analysis but without further details, I don't
think the issue reported here can happen.

Best regards,
Hervé

[PATCH v13 10/10] PCI: of: Avoid np->data usage for the node changeset

[Herve Codina]

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: <stable+noautosel@kernel.org> # Issue not triggered but could be a problem
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 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

Re: [PATCH v13 10/10] PCI: of: Avoid np->data usage for the node changeset

[sashiko-bot]

> 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
> [ ... ]
> 
> Fixes: 407d1a51921e ("PCI: Create device tree node for bridge")
> Fixes: 1f340724419e ("PCI: of: Create device tree PCI host bridge node")
> Cc: <stable+noautosel@kernel.org> # Issue not triggered but could be a problem
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=10

Re: [PATCH v13 10/10] PCI: of: Avoid np->data usage for the node changeset

[Bjorn Helgaas]

On Mon, Oct 12, 2026 at 04:28:24PM +0200, Herve Codina wrote:
> 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: <stable+noautosel@kernel.org> # Issue not triggered but could be a problem
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
>  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
> 

Re: [PATCH v13 05/10] cxl/test: Use fw_devlink_set_device()

[sashiko-bot]

> The code set directly fwnode.dev field.
> 
> Use the dedicated fw_devlink_set_device() helper to perform this
> operation.
> 
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=5

Re: [PATCH v13 01/10] driver core: fw_devlink: Introduce fw_devlink_set_device()

[sashiko-bot]

> Setting fwnode->dev is specific to fw_devlink.
> 
> In order to avoid having a direct 'fwnode->dev = dev;' in several
> place in the kernel, introduce fw_devlink_set_device() helper to perform
> this operation.
> 
> Having this helper allows to hide the fwnode devlink related stuff
> behind the helper.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=1

Re: [PATCH v13 09/10] PCI: of: Remove fwnode_dev_initialized() call for a PCI root bridge node

[sashiko-bot]

> During the instantiation of devices described by a device-tree overlay
> applied on a PCI device, devlink displays the following kind of debug
> messages instead of creating the expected links:
>    'Not linking xxxx - might never become dev'
> 
> Without those expected links, the device removal order cannot be
> correct.
> 
> Those debug traces are printed by fw_devlink_create_devlink(). In our
> use case, they are all printed because the supplier of the link has at
> least one of its ancestor with its fwnode flag FWNODE_FLAG_INITIALIZED
> set.
> 
> The culprit ancestor is the PCI root bridge.
> 
> [ ... ]
> are correctly created.
> 
> Fixes: 1f340724419e ("PCI: of: Create device tree PCI host bridge node")
> Cc: stable@vger.kernel.org
> Signed-off-by: Herve Codina <herve.codina@bootlin.com>

Sashiko has reviewed this patch and found no issues. It looks great!

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261012142826.159178-1-herve.codina@bootlin.com?part=9