From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Krempa , yunzheng@redhat.com, Amit Shah , Rusty Russell Subject: [ 03/48] virtio: rng: disallow multiple device registrations, fixes crashes Date: Mon, 18 Mar 2013 14:08:11 -0700 Message-Id: <20130318210810.498262557@linuxfoundation.org> In-Reply-To: <20130318210810.247845918@linuxfoundation.org> References: <20130318210810.247845918@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amit Shah commit e84e7a56a3aa2963db506299e29a5f3f09377f9b upstream. The code currently only supports one virtio-rng device at a time. Invoking guests with multiple devices causes the guest to blow up. Check if we've already registered and initialised the driver. Also cleanup in case of registration errors or hot-unplug so that a new device can be used. Reported-by: Peter Krempa Reported-by: Signed-off-by: Amit Shah Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman --- drivers/char/hw_random/virtio-rng.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -89,14 +89,22 @@ static int virtrng_probe(struct virtio_d { int err; + if (vq) { + /* We only support one device for now */ + return -EBUSY; + } /* We expect a single virtqueue. */ vq = virtio_find_single_vq(vdev, random_recv_done, "input"); - if (IS_ERR(vq)) - return PTR_ERR(vq); + if (IS_ERR(vq)) { + err = PTR_ERR(vq); + vq = NULL; + return err; + } err = hwrng_register(&virtio_hwrng); if (err) { vdev->config->del_vqs(vdev); + vq = NULL; return err; } @@ -108,6 +116,7 @@ static void __devexit virtrng_remove(str vdev->config->reset(vdev); hwrng_unregister(&virtio_hwrng); vdev->config->del_vqs(vdev); + vq = NULL; } static struct virtio_device_id id_table[] = {