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authorAmit Shah <amit.shah@redhat.com>2013-03-08 11:30:18 +1100
committerRusty Russell <rusty@rustcorp.com.au>2013-03-08 11:30:43 +1100
commite84e7a56a3aa2963db506299e29a5f3f09377f9b (patch)
tree3c368fc922977af1760932c55fcfb69e20126cfa /drivers/char/hw_random
parentf7f154f1246ccc5a0a7e9ce50932627d60a0c878 (diff)
virtio: rng: disallow multiple device registrations, fixes crashes
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> Cc: stable@kernel.org
Diffstat (limited to 'drivers/char/hw_random')
-rw-r--r--drivers/char/hw_random/virtio-rng.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 10fd71ccf587..6bf4d47324eb 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -92,14 +92,22 @@ static int probe_common(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;
}
@@ -112,6 +120,7 @@ static void remove_common(struct virtio_device *vdev)
busy = false;
hwrng_unregister(&virtio_hwrng);
vdev->config->del_vqs(vdev);
+ vq = NULL;
}
static int virtrng_probe(struct virtio_device *vdev)