Commit 1b15a563 authored Jul 30, 2019 by John Garry Committed by Wei Xu Aug 13, 2019

bus: hisi_lpc: Unregister logical PIO range to avoid potential use-after-free



If, after registering a logical PIO range, the driver probe later fails,
the logical PIO range memory will be released automatically.

This causes an issue, in that the logical PIO range is not unregistered
and the released range memory may be later referenced.

Fix by unregistering the logical PIO range.

And since we now unregister the logical PIO range for probe failure, avoid
the special ordering of setting logical PIO range ops, which was the
previous (poor) attempt at a safeguard against this.

Cc: stable@vger.kernel.org
Fixes: adf38bb0 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings")
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>

parent b884e2de

drivers/bus/hisi_lpc.c

+6 −5

Original line number	Diff line number	Diff line
		@@ -606,24 +606,25 @@ static int hisi_lpc_probe(struct platform_device *pdev)
		range->fwnode = dev->fwnode;
		range->flags = LOGIC_PIO_INDIRECT;
		range->size = PIO_INDIRECT_SIZE;
		range->hostdata = lpcdev;
		range->ops = &hisi_lpc_ops;
		lpcdev->io_host = range;

		ret = logic_pio_register_range(range);
		if (ret) {
		dev_err(dev, "register IO range failed (%d)!\n", ret);
		return ret;
		}
		lpcdev->io_host = range;

		/* register the LPC host PIO resources */
		if (acpi_device)
		ret = hisi_lpc_acpi_probe(dev);
		else
		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
		if (ret)
		if (ret) {
		logic_pio_unregister_range(range);
		return ret;

		lpcdev->io_host->hostdata = lpcdev;
		lpcdev->io_host->ops = &hisi_lpc_ops;
		}

		io_end = lpcdev->io_host->io_start + lpcdev->io_host->size;
		dev_info(dev, "registered range [%pa - %pa]\n",

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