[PATCH v4 03/12] i3c: master: Support ACPI enumeration of child devices

[Frank Li]

On Tue, Jun 16, 2026 at 10:15:14AM +0000, sashiko-bot at kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] devm_kzalloc allocated 'boardinfo' is leaked for every ACPI child node that is ignored because it lacks I2C/I3C resources.
> --
>
> commit 9a388c2056a553d628ce4b8b623a812d4aa08951
> Author: Akhil R <akhilrajeev at nvidia.com>
>
> i3c: master: Support ACPI enumeration of child devices
>
> This commit adds support for describing I3C and I2C devices via ACPI tables,
> rather than relying solely on the device tree reg property. It implements
> reading _ADR and LVR properties from ACPI resources to retrieve the static
> address and other device properties.
>
> > diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c
> > index 3b19a5e8f46d0..f0e05bcac26da 100644
> > --- a/drivers/i3c/master.c
> > +++ b/drivers/i3c/master.c
>
> [ ... ]
>
> > @@ -2708,6 +2762,74 @@ static int i3c_master_add_dev(struct i3c_master_controller *master,
> >  	return ret;
> >  }
> >
> > +#ifdef CONFIG_ACPI
> > +static int i3c_master_add_acpi_dev(struct i3c_master_controller *master,
> > +				   struct fwnode_handle *fwnode)
> > +{
> > +	struct acpi_device *adev = to_acpi_device_node(fwnode);
> > +	acpi_bus_address adr;
> > +	u32 reg[3] = { 0 };
> > +	int ret;
> > +
> > +	/*
> > +	 * If the ACPI table entry has _ADR method, it's an I3C device.
> > +	 * Otherwise it may be an I2C device described by an I2cSerialBus
> > +	 * resource. If no I2cSerialBus resource is found, ignore the entry.
> > +	 */
> > +	if (!acpi_has_method(adev->handle, "_ADR")) {
> > +		ret = i3c_master_add_i2c_boardinfo(master, fwnode, reg);
> > +		if (ret == -ENODEV)
> > +			return 0;
>
> [Severity: Medium]
> Does this leak the boardinfo allocated in i3c_master_add_i2c_boardinfo()?
>
> If an ACPI child lacks an _ADR method, i3c_master_add_i2c_boardinfo()
> unconditionally allocates boardinfo using devm_kzalloc().
>
> If the node also lacks an I2cSerialBus resource, i3c_acpi_add_i2c_boardinfo()
> returns -ENODEV. This causes i3c_master_add_i2c_boardinfo() to return -ENODEV
> without freeing the allocated boardinfo.
>
> Because we catch -ENODEV here and return 0, the overall bus probe continues
> and ultimately succeeds. This means the devres-allocated memory stays tied
> to the master device, leaking sizeof(struct i2c_dev_boardinfo) for every
> ignored ACPI child node.

Is it true?

Frank

>
> > +
> > +		return ret;
> > +	}
> > +
> > +	adr = acpi_device_adr(adev);
>
> [ ... ]
>
> --
> Sashiko AI review · https://sashiko.dev/#/patchset/20260616095429.3947205-1-akhilrajeev@nvidia.com?part=3