Messages in this thread | | | Date | Tue, 29 Oct 2013 07:32:35 -0400 | From | Neil Horman <> | Subject | Re: [PATCH v3 1/3] msi: free msi_desc entry only after we've released the kobject |
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On Tue, Oct 29, 2013 at 11:30:30AM +0100, Veaceslav Falico wrote: > Currently, we first do kobject_put(&entry->kobj) and the kfree(entry), > however kobject_put() doesn't guarantee us that it was the last reference > and that the kobj isn't used currently by someone else, so after we > kfree(entry) with the struct kobject - other users will begin using the > freed memory, instead of the actual kobject. > > Fix this by using the kobject->release callback, which is called last when > the kobject is indeed not used and is cleaned up - it's msi_kobj_release(), > which can do the kfree(entry) safely (kobject_put/cleanup doesn't use the > kobj itself after ->release() was called, so we're safe). > > In case we've failed to create the sysfs directories - just kfree() > it - cause we don't have the kobjects attached. > > Also, remove the same functionality from populate_msi_sysfs(), cause on > failure we anyway call free_msi_irqs(), which will take care of all the > kobjects properly. > > And add the forgotten pci_dev_put(pdev) in case of failure to register the > kobject in populate_msi_sysfs(). > > CC: Bjorn Helgaas <bhelgaas@google.com> > CC: Neil Horman <nhorman@tuxdriver.com> > CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > CC: linux-pci@vger.kernel.org > CC: linux-kernel@vger.kernel.org > Signed-off-by: Veaceslav Falico <vfalico@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com>
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