Stefano Garzarella
2022-Mar-10 13:36 UTC
[PATCH v2] vsock: each transport cycles only on its own sockets
On Thu, Mar 10, 2022 at 10:28:29PM +0900, Jiyong Park wrote:>When iterating over sockets using vsock_for_each_connected_socket, make >sure that a transport filters out sockets that don't belong to the >transport. > >There actually was an issue caused by this; in a nested VM >configuration, destroying the nested VM (which often involves the >closing of /dev/vhost-vsock if there was h2g connections to the nested >VM) kills not only the h2g connections, but also all existing g2h >connections to the (outmost) host which are totally unrelated. > >Tested: Executed the following steps on Cuttlefish (Android running on a >VM) [1]: (1) Enter into an `adb shell` session - to have a g2h >connection inside the VM, (2) open and then close /dev/vhost-vsock by >`exec 3< /dev/vhost-vsock && exec 3<&-`, (3) observe that the adb >session is not reset. > >[1] https://android.googlesource.com/device/google/cuttlefish/ > >Fixes: c0cfa2d8a788 ("vsock: add multi-transports support") >Signed-off-by: Jiyong Park <jiyong at google.com> >--- >Changes in v2: > - Squashed into a single patch > > drivers/vhost/vsock.c | 3 ++- > include/net/af_vsock.h | 3 ++- > net/vmw_vsock/af_vsock.c | 9 +++++++-- > net/vmw_vsock/virtio_transport.c | 7 +++++-- > net/vmw_vsock/vmci_transport.c | 3 ++- > 5 files changed, 18 insertions(+), 7 deletions(-) > >diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c >index 37f0b4274113..e6c9d41db1de 100644 >--- a/drivers/vhost/vsock.c >+++ b/drivers/vhost/vsock.c >@@ -753,7 +753,8 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file) > > /* Iterating over all connections for all CIDs to find orphans is > * inefficient. Room for improvement here. */ >- vsock_for_each_connected_socket(vhost_vsock_reset_orphans); >+ vsock_for_each_connected_socket(&vhost_transport.transport, >+ vhost_vsock_reset_orphans); > > /* Don't check the owner, because we are in the release path, so we > * need to stop the vsock device in any case. >diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h >index ab207677e0a8..f742e50207fb 100644 >--- a/include/net/af_vsock.h >+++ b/include/net/af_vsock.h >@@ -205,7 +205,8 @@ struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr); > struct sock *vsock_find_connected_socket(struct sockaddr_vm *src, > struct sockaddr_vm *dst); > void vsock_remove_sock(struct vsock_sock *vsk); >-void vsock_for_each_connected_socket(void (*fn)(struct sock *sk)); >+void vsock_for_each_connected_socket(struct vsock_transport *transport, >+ void (*fn)(struct sock *sk)); > int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk); > bool vsock_find_cid(unsigned int cid); > >diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >index 38baeb189d4e..f04abf662ec6 100644 >--- a/net/vmw_vsock/af_vsock.c >+++ b/net/vmw_vsock/af_vsock.c >@@ -334,7 +334,8 @@ void vsock_remove_sock(struct vsock_sock *vsk) > } > EXPORT_SYMBOL_GPL(vsock_remove_sock); > >-void vsock_for_each_connected_socket(void (*fn)(struct sock *sk)) >+void vsock_for_each_connected_socket(struct vsock_transport *transport, >+ void (*fn)(struct sock *sk)) > { > int i; > >@@ -343,8 +344,12 @@ void vsock_for_each_connected_socket(void (*fn)(struct sock *sk)) > for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) { > struct vsock_sock *vsk; > list_for_each_entry(vsk, &vsock_connected_table[i], >- connected_table) >+ connected_table) { >+ if (vsk->transport != transport) >+ continue; >+ > fn(sk_vsock(vsk)); >+ } > } > > spin_unlock_bh(&vsock_table_lock); >diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c >index fb3302fff627..5afc194a58bb 100644 >--- a/net/vmw_vsock/virtio_transport.c >+++ b/net/vmw_vsock/virtio_transport.c >@@ -24,6 +24,7 @@ > static struct workqueue_struct *virtio_vsock_workqueue; > static struct virtio_vsock __rcu *the_virtio_vsock; > static DEFINE_MUTEX(the_virtio_vsock_mutex); /* protects the_virtio_vsock */ >+static struct virtio_transport virtio_transport; /* forward declaration */ > > struct virtio_vsock { > struct virtio_device *vdev; >@@ -384,7 +385,8 @@ static void virtio_vsock_event_handle(struct virtio_vsock *vsock, > switch (le32_to_cpu(event->id)) { > case VIRTIO_VSOCK_EVENT_TRANSPORT_RESET: > virtio_vsock_update_guest_cid(vsock); >- vsock_for_each_connected_socket(virtio_vsock_reset_sock); >+ vsock_for_each_connected_socket(&virtio_transport.transport, >+ virtio_vsock_reset_sock); > break; > } > } >@@ -662,7 +664,8 @@ static void virtio_vsock_remove(struct virtio_device *vdev) > synchronize_rcu(); > > /* Reset all connected sockets when the device disappear */ >- vsock_for_each_connected_socket(virtio_vsock_reset_sock); >+ vsock_for_each_connected_socket(&virtio_transport.transport, >+ virtio_vsock_reset_sock); > > /* Stop all work handlers to make sure no one is accessing the device, > * so we can safely call virtio_reset_device(). >diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c >index 7aef34e32bdf..735d5e14608a 100644 >--- a/net/vmw_vsock/vmci_transport.c >+++ b/net/vmw_vsock/vmci_transport.c >@@ -882,7 +882,8 @@ static void vmci_transport_qp_resumed_cb(u32 sub_id, > const struct vmci_event_data *e_data, > void *client_data) > { >- vsock_for_each_connected_socket(vmci_transport_handle_detach); >+ vsock_for_each_connected_socket(&vmci_transport, >+ vmci_transport_handle_detach); > } > > static void vmci_transport_recv_pkt_work(struct work_struct *work)This breaks the build of vmci-transport: ../net/vmw_vsock/vmci_transport.c: In function ?vmci_transport_qp_resumed_cb?: ../net/vmw_vsock/vmci_transport.c:885:42: error: ?vmci_transport? undeclared (first use in this function) 885 | vsock_for_each_connected_socket(&vmci_transport, | ^~~~~~~~~~~~~~ ../net/vmw_vsock/vmci_transport.c:885:42: note: each undeclared identifier is reported only once for each function it appears in Stefano