3.6-stable review patch. If anyone has any objections, please let me know.
------------------ From: Cornelia Huck <[email protected]> commit 237242bddc99041e15a4ca51b8439657cadaff17 upstream. Virtio wants to release used indices after the corresponding virtio device has been unregistered. However, virtio does not hold an extra reference, giving up its last reference with device_unregister(), making accessing dev->index afterwards invalid. I actually saw problems when testing my (not-yet-merged) virtio-ccw code: - device_add virtio-net,id=xxx -> creates device virtio<n> with n>0 - device_del xxx -> deletes virtio<n>, but calls ida_simple_remove with an index of 0 - device_add virtio-net,id=xxx -> tries to add virtio0, which is still in use... So let's save the index we want to release before calling device_unregister(). Signed-off-by: Cornelia Huck <[email protected]> Acked-by: Sjur Brændeland <[email protected]> Signed-off-by: Rusty Russell <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/virtio/virtio.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/virtio/virtio.c +++ b/drivers/virtio/virtio.c @@ -225,8 +225,10 @@ EXPORT_SYMBOL_GPL(register_virtio_device void unregister_virtio_device(struct virtio_device *dev) { + int index = dev->index; /* save for after device release */ + device_unregister(&dev->dev); - ida_simple_remove(&virtio_index_ida, dev->index); + ida_simple_remove(&virtio_index_ida, index); } EXPORT_SYMBOL_GPL(unregister_virtio_device); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
