[PATCH] PCI: Check parent for NULL in of_pci_bus_release_domain_nr()

[PATCH] PCI: Check parent for NULL in of_pci_bus_release_domain_nr()

[Sergey Shtylyov]

of_pci_bus_find_domain_nr() allows its parent parameter to be NULL but
of_pci_bus_release_domain_nr() (that undoes its effect) doesn't -- that
means it's going to blow up while calling of_get_pci_domain_nr() if the
parent parameter indeed happens to be NULL.  Add the missing NULL check.

Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.

Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()")
Signed-off-by: Sergey Shtylyov <s.shtylyov@auroraos.dev>
---
 drivers/pci/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 13dbb405dc31..9fc4c2226b03 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -6591,7 +6591,7 @@ static void of_pci_bus_release_domain_nr(struct device *parent, int domain_nr)
 		return;
 
 	/* Release domain from IDA where it was allocated. */
-	if (of_get_pci_domain_nr(parent->of_node) == domain_nr)
+	if (parent && of_get_pci_domain_nr(parent->of_node) == domain_nr)
 		ida_free(&pci_domain_nr_static_ida, domain_nr);
 	else
 		ida_free(&pci_domain_nr_dynamic_ida, domain_nr);
-- 
2.52.0

Re: [PATCH] PCI: Check parent for NULL in of_pci_bus_release_domain_nr()

[Sergey Shtylyov]

On 1/27/26 11:39 PM, Sergey Shtylyov wrote:

> of_pci_bus_find_domain_nr() allows its parent parameter to be NULL but
> of_pci_bus_release_domain_nr() (that undoes its effect) doesn't -- that
> means it's going to blow up while calling of_get_pci_domain_nr() if the
> parent parameter indeed happens to be NULL.  Add the missing NULL check.
> 
> Found by Linux Verification Center (linuxtesting.org) with the Svace static
> analysis tool.
> 
> Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()")
> Signed-off-by: Sergey Shtylyov <s.shtylyov@auroraos.dev>
> ---

   Forgot to add that this patch was done against the for-linus branch of
the pci.git repo...

[...]

MBR, Sergey

Re: [PATCH] PCI: Check parent for NULL in of_pci_bus_release_domain_nr()

[Bjorn Helgaas]

On Tue, Jan 27, 2026 at 11:39:42PM +0300, Sergey Shtylyov wrote:
> of_pci_bus_find_domain_nr() allows its parent parameter to be NULL but
> of_pci_bus_release_domain_nr() (that undoes its effect) doesn't -- that
> means it's going to blow up while calling of_get_pci_domain_nr() if the
> parent parameter indeed happens to be NULL.  Add the missing NULL check.
> 
> Found by Linux Verification Center (linuxtesting.org) with the Svace static
> analysis tool.
> 
> Fixes: c14f7ccc9f5d ("PCI: Assign PCI domain IDs by ida_alloc()")
> Signed-off-by: Sergey Shtylyov <s.shtylyov@auroraos.dev>

Applied to pci/enumeration for v6.20, thanks!

> ---
>  drivers/pci/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 13dbb405dc31..9fc4c2226b03 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -6591,7 +6591,7 @@ static void of_pci_bus_release_domain_nr(struct device *parent, int domain_nr)
>  		return;
>  
>  	/* Release domain from IDA where it was allocated. */
> -	if (of_get_pci_domain_nr(parent->of_node) == domain_nr)
> +	if (parent && of_get_pci_domain_nr(parent->of_node) == domain_nr)
>  		ida_free(&pci_domain_nr_static_ida, domain_nr);
>  	else
>  		ida_free(&pci_domain_nr_dynamic_ida, domain_nr);
> -- 
> 2.52.0
>