Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752044Ab3CREnf (ORCPT ); Mon, 18 Mar 2013 00:43:35 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33561 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751763Ab3CREai (ORCPT ); Mon, 18 Mar 2013 00:30:38 -0400 Message-Id: <20130318042149.175740743@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 18 Mar 2013 04:22:35 +0000 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, Amit Shah , Peter Krempa , , Rusty Russell Subject: [ 51/82] virtio: rng: disallow multiple device registrations, fixes crashes In-Reply-To: <20130318042144.234468645@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:d98f:da4e:f620:7bea X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1878 Lines: 66 3.2-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: Ben Hutchings --- 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[] = { -- 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/