Re: [PATCH v5 4/8] PCI: vmd: Add vmd_create_bus()

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Memory allocated by kasprintf for resource names is leaked on vmd_enable_domain() error paths.
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commit 1ab8bc19707a3b648b92906666ae290aa0884407
Author: Szymon Durawa <szymon.durawa@linux.intel.com>

PCI: vmd: Add vmd_create_bus()

This commit moves the VMD bus initialization logic into a new helper function
vmd_create_bus(). It aims to simplify the domain enablement code without
introducing functional changes.

> diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c
> index 443a0cefb7f74..c0a953df5f238 100644
> --- a/drivers/pci/controller/vmd.c
> +++ b/drivers/pci/controller/vmd.c

[ ... ]

> @@ -968,25 +994,12 @@ static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
>  
>  	sd->node = pcibus_to_node(vmd->dev->bus);
>  
> -	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
> -				       &vmd_ops, sd, &resources);
> -	if (!vmd->bus) {
> -		pci_bus_release_emul_domain_nr(sd->domain);
> -		pci_free_resource_list(&resources);
> -		vmd_remove_irq_domain(vmd);
> -		return -ENODEV;
> +	ret = vmd_create_bus(vmd, sd, offset);
> +	if (ret) {
> +		pci_err(vmd->dev, "Can't create bus: %d\n", ret);
> +		return ret;

[Severity: High]
Does this error path in vmd_enable_domain() leak the resource names allocated
by kasprintf() during the earlier memory bar configuration?

If vmd_create_bus() fails and returns an error, does this early return
lack the necessary rollback logic? Could this leave the previously
initialized bus active while its sysdata pointer (the vmd_dev struct)
is later freed by devres, resulting in a use-after-free?

>  	}
>  
> -	vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
> -				   to_pci_host_bridge(vmd->bus->bridge));
> -
> -	vmd_attach_resources(vmd);
> -	if (vmd->irq_domain)
> -		dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
> -	else
> -		dev_set_msi_domain(&vmd->bus->dev,
> -				   dev_get_msi_domain(&vmd->dev->dev));
> -
>  	WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
>  			       "domain"), "Can't create symlink to domain\n");
>

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Sashiko AI review · https://sashiko.dev/#/patchset/20260625082940.1290740-1-szymon.durawa@linux.intel.com?part=4