Re: [Xen-devel] [PATCH] xen-pciback: fix up cleanup path when alloc fails

[David Vrabel <david.vrabel@xxxxxxxxxx>]

On 26/11/15 20:32, Doug Goldstein wrote:
> When allocating a pciback device fails, avoid the possibility of a
> use after free.

We should not require clearing drvdata for correctness.  We should
ensure we retain drvdata for as long as it is needed.

I note that pcistub_device_release() has:

        kfree(dev_data);
        pci_set_drvdata(dev, NULL);

        /* Clean-up the device */
        xen_pcibk_config_free_dyn_fields(dev);
        xen_pcibk_config_free_dev(dev);

Which should (at a minimum) be reordered to move the kfree(dev_data) to
after the calls that require it

David

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