vsock/virtio: Initialization of the dangling pointer occurring in vsk->trans

ImV4bel · gregkh · commit 5f970935d099 · 2024-11-14T13:21:16.000+01:00
commit 6ca5753 upstream. During loopback communication, a dangling pointer can be created in vsk->trans, potentially leading to a Use-After-Free condition. This issue is resolved by initializing vsk->trans to NULL. Cc: stable <stable@kernel.org> Fixes: 06a8fc7 ("VSOCK: Introduce virtio_vsock_common.ko") Signed-off-by: Hyunwoo Kim <v4bel@theori.io> Signed-off-by: Wongi Lee <qwerty@theori.io> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Message-Id: <2024102245-strive-crib-c8d3@gregkh> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
@@ -1087,6 +1087,7 @@ void virtio_transport_destruct(struct vsock_sock *vsk)
 	struct virtio_vsock_sock *vvs = vsk->trans;
 
 	kfree(vvs);
+	vsk->trans = NULL;
 }
 EXPORT_SYMBOL_GPL(virtio_transport_destruct);
 

Original file line number	Diff line number	Diff line change
`@@ -1087,6 +1087,7 @@ void virtio_transport_destruct(struct vsock_sock *vsk)`
`1087`	`1087`	`struct virtio_vsock_sock *vvs = vsk->trans;`
`1088`	`1088`
`1089`	`1089`	`kfree(vvs);`
	`1090`	`+ vsk->trans = NULL;`
`1090`	`1091`	`}`
`1091`	`1092`	`EXPORT_SYMBOL_GPL(virtio_transport_destruct);`
`1092`	`1093`