| From | Luis Henriques <> | Subject | [PATCH 022/150] virtio: rng: disallow multiple device registrations, fixes crashes | Date | Tue, 26 Mar 2013 15:18:41 +0000 |
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3.5.7.9 -stable review patch. If anyone has any objections, please let me know.
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From: Amit Shah <amit.shah@redhat.com>
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 <pkrempa@redhat.com> Reported-by: <yunzheng@redhat.com> Signed-off-by: Amit Shah <amit.shah@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/char/hw_random/virtio-rng.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 723725b..171380b 100644 --- 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_device *vdev) { 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(struct virtio_device *vdev) vdev->config->reset(vdev); hwrng_unregister(&virtio_hwrng); vdev->config->del_vqs(vdev); + vq = NULL; } static struct virtio_device_id id_table[] = { -- 1.8.1.2
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