2.6.29-stable review patch. If anyone has any objections, please let us know. ------------------ From: Ian Campbell commit 28afea5b2ffaa48f4f43d22ae8edcc384c05df80 upstream. This situation can occur when attempting to attach a block device whose backend is an empty physical CD-ROM driver. The backend in this case will go directly from the Initialising state to Closing->Closed. Previously this would result in a NULL pointer deref on info->gd (xenbus_dev_fatal does not return as a1a15ac5 seems to expect) Signed-off-by: Ian Campbell Acked-by: Jeremy Fitzhardinge Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/block/xen-blkfront.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -977,8 +977,10 @@ static void backend_changed(struct xenbu break; case XenbusStateClosing: - if (info->gd == NULL) - xenbus_dev_fatal(dev, -ENODEV, "gd is NULL"); + if (info->gd == NULL) { + xenbus_frontend_closed(dev); + break; + } bd = bdget_disk(info->gd, 0); if (bd == NULL) xenbus_dev_fatal(dev, -ENODEV, "bdget failed"); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/