Virtio serial device controls the lifetime of virtio-serial-bus and
virtio-serial-bus links back to the device via its hotplug-handler
property. This extra ref-count prevents the device from getting
finalized, leaving the VirtIODevice memory listener registered and
leading to use-after-free later on.
This patch addresses the same issue as Fam Zheng's
"virtio-scsi: Unset hotplug handler when unrealize"
only for a different virtio device.
Cc: qemu-stable@nongnu.org
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
---
hw/char/virtio-serial-bus.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index d797a67..aa9c11a 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -1121,6 +1121,9 @@ static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp)
timer_free(vser->post_load->timer);
g_free(vser->post_load);
}
+
+ qbus_set_hotplug_handler(BUS(&vser->bus), NULL, errp);
+
virtio_cleanup(vdev);
}
--
2.9.3
On 30/05/2017 10:59, Ladi Prosek wrote: > Virtio serial device controls the lifetime of virtio-serial-bus and > virtio-serial-bus links back to the device via its hotplug-handler > property. This extra ref-count prevents the device from getting > finalized, leaving the VirtIODevice memory listener registered and > leading to use-after-free later on. > > This patch addresses the same issue as Fam Zheng's > "virtio-scsi: Unset hotplug handler when unrealize" > only for a different virtio device. > > Cc: qemu-stable@nongnu.org > Signed-off-by: Ladi Prosek <lprosek@redhat.com> > --- > hw/char/virtio-serial-bus.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c > index d797a67..aa9c11a 100644 > --- a/hw/char/virtio-serial-bus.c > +++ b/hw/char/virtio-serial-bus.c > @@ -1121,6 +1121,9 @@ static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp) > timer_free(vser->post_load->timer); > g_free(vser->post_load); > } > + > + qbus_set_hotplug_handler(BUS(&vser->bus), NULL, errp); > + > virtio_cleanup(vdev); > } > > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
On Tue, 05/30 10:59, Ladi Prosek wrote: > Virtio serial device controls the lifetime of virtio-serial-bus and > virtio-serial-bus links back to the device via its hotplug-handler > property. This extra ref-count prevents the device from getting > finalized, leaving the VirtIODevice memory listener registered and > leading to use-after-free later on. > > This patch addresses the same issue as Fam Zheng's > "virtio-scsi: Unset hotplug handler when unrealize" > only for a different virtio device. > > Cc: qemu-stable@nongnu.org > Signed-off-by: Ladi Prosek <lprosek@redhat.com> > --- > hw/char/virtio-serial-bus.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c > index d797a67..aa9c11a 100644 > --- a/hw/char/virtio-serial-bus.c > +++ b/hw/char/virtio-serial-bus.c > @@ -1121,6 +1121,9 @@ static void virtio_serial_device_unrealize(DeviceState *dev, Error **errp) > timer_free(vser->post_load->timer); > g_free(vser->post_load); > } > + > + qbus_set_hotplug_handler(BUS(&vser->bus), NULL, errp); > + > virtio_cleanup(vdev); > } > > -- > 2.9.3 > > Reviewed-by: Fam Zheng <famz@redhat.com>
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