From: "Denis V. Lunev" <den@openvz.org> mainline inclusion from mainline-v7.3-rc1 commit 7e17eef04600c399c7e0f5ce765da5cf9d40d8e1 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/19410 CVE: CVE-2026-90129 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Commit 8bd2fa086a04 ("virtio: break and reset virtio devices on device_shutdown()") added a generic virtio bus .shutdown handler that breaks and resets every virtio device during device_shutdown(), i.e. on reboot and kexec. virtio_balloon provides no .shutdown of its own, so that generic path runs while the balloon's asynchronous work is still armed. Once the device has been broken, virtqueue_add_inbuf() in virtballoon_free_page_report() returns -EIO and trips its WARN_ON_ONCE(). On a kernel booted with panic_on_warn that turns an ordinary reboot, for example a kexec based upgrade, into a fatal panic in the middle of device_shutdown(), so the machine never reaches the new kernel. Relaxing that single WARN_ON_ONCE() would only hide the symptom: the inflate/deflate and OOM paths do not warn, they call wait_event(vb->acked, ...) and would instead block forever on a broken queue that can no longer complete. The device has to be quiesced, not just kept quiet. Add a .shutdown handler that quiesces the balloon via the shared virtballoon_quiesce() helper while the device is still alive, and only then breaks and resets it via virtio_device_shutdown(). Unlike virtballoon_remove() the balloon workqueue is not destroyed, as shutdown does not free the device and cancel_work_sync() together with stop_update already prevent any further work from being queued. Fixes: 8bd2fa086a04 ("virtio: break and reset virtio devices on device_shutdown()") Signed-off-by: Denis V. Lunev <den@openvz.org> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-ID: <20260624140846.2616797-4-den@openvz.org> Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> --- drivers/virtio/virtio_balloon.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c index b14fafcf8c6e..8181f058b78c 100644 --- a/drivers/virtio/virtio_balloon.c +++ b/drivers/virtio/virtio_balloon.c @@ -1255,6 +1255,12 @@ static void virtballoon_remove(struct virtio_device *vdev) kfree(vb); } +static void virtballoon_shutdown(struct virtio_device *vdev) +{ + virtballoon_quiesce(vdev->priv); + virtio_device_shutdown(vdev); +} + #ifdef CONFIG_PM_SLEEP static int virtballoon_freeze(struct virtio_device *vdev) { @@ -1345,6 +1351,7 @@ static struct virtio_driver virtio_balloon_driver = { .validate = virtballoon_validate, .probe = virtballoon_probe, .remove = virtballoon_remove, + .shutdown = virtballoon_shutdown, .config_changed = virtballoon_changed, #ifdef CONFIG_PM_SLEEP .freeze = virtballoon_freeze, -- 2.34.1