| Message ID | 9712243.It8gvaRCs0@vostro.rjw.lan (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Thu, Nov 14, 2013 at 12:26:47AM +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > When associating a "physical" device with an ACPI device object > acpi_bind_one() only uses get_device() to increment the reference > counter of the former, but there is no reason not to do that with > the latter too. Among other things, that may help to avoid > use-after-free when an ACPI device object is freed without calling > acpi_unbind_one() for all "physical" devices associated with it > (that only can happen in buggy code, but then it's better if the > kernel doesn't crash as a result of a bug). > > For this reason, modify acpi_bind_one() to apply get_device() to > the ACPI device object too and update acpi_unbind_one() to drop > that reference using put_device() as appropriate. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 2013?11?14? 07:26, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > When associating a "physical" device with an ACPI device object > acpi_bind_one() only uses get_device() to increment the reference > counter of the former, but there is no reason not to do that with > the latter too. Among other things, that may help to avoid > use-after-free when an ACPI device object is freed without calling > acpi_unbind_one() for all "physical" devices associated with it > (that only can happen in buggy code, but then it's better if the > kernel doesn't crash as a result of a bug). > > For this reason, modify acpi_bind_one() to apply get_device() to > the ACPI device object too and update acpi_unbind_one() to drop > that reference using put_device() as appropriate. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > drivers/acpi/glue.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > Index: linux-pm/drivers/acpi/glue.c > =================================================================== > --- linux-pm.orig/drivers/acpi/glue.c > +++ linux-pm/drivers/acpi/glue.c > @@ -217,6 +217,7 @@ int acpi_bind_one(struct device *dev, ac > if (!acpi_dev) > return -EINVAL; > > + get_device(&acpi_dev->dev); > get_device(dev); > physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL); > if (!physical_node) { > @@ -243,6 +244,7 @@ int acpi_bind_one(struct device *dev, ac > goto err; > > put_device(dev); > + put_device(&acpi_dev->dev); > return 0; > } > if (pn->node_id == node_id) { > @@ -282,6 +284,7 @@ int acpi_bind_one(struct device *dev, ac > err: > ACPI_COMPANION_SET(dev, NULL); > put_device(dev); > + put_device(&acpi_dev->dev); > return retval; > } > EXPORT_SYMBOL_GPL(acpi_bind_one); > @@ -307,8 +310,9 @@ int acpi_unbind_one(struct device *dev) > sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name); > sysfs_remove_link(&dev->kobj, "firmware_node"); > ACPI_COMPANION_SET(dev, NULL); > - /* acpi_bind_one() increase refcnt by one. */ > + /* Drop references taken by acpi_bind_one(). */ > put_device(dev); > + put_device(&acpi_dev->dev); > kfree(entry); > break; > } > Reviewed-by: Lan Tianyu <tianyu.lan@intel.com>
Index: linux-pm/drivers/acpi/glue.c =================================================================== --- linux-pm.orig/drivers/acpi/glue.c +++ linux-pm/drivers/acpi/glue.c @@ -217,6 +217,7 @@ int acpi_bind_one(struct device *dev, ac if (!acpi_dev) return -EINVAL; + get_device(&acpi_dev->dev); get_device(dev); physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL); if (!physical_node) { @@ -243,6 +244,7 @@ int acpi_bind_one(struct device *dev, ac goto err; put_device(dev); + put_device(&acpi_dev->dev); return 0; } if (pn->node_id == node_id) { @@ -282,6 +284,7 @@ int acpi_bind_one(struct device *dev, ac err: ACPI_COMPANION_SET(dev, NULL); put_device(dev); + put_device(&acpi_dev->dev); return retval; } EXPORT_SYMBOL_GPL(acpi_bind_one); @@ -307,8 +310,9 @@ int acpi_unbind_one(struct device *dev) sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name); sysfs_remove_link(&dev->kobj, "firmware_node"); ACPI_COMPANION_SET(dev, NULL); - /* acpi_bind_one() increase refcnt by one. */ + /* Drop references taken by acpi_bind_one(). */ put_device(dev); + put_device(&acpi_dev->dev); kfree(entry); break; }