nvmet-rdma: fix use-after-free when a port is removed

When removing a port, all its controllers are being removed, but there
are queues on the port that doesn't belong to any controller (during
connection time). This causes a use-after-free bug for any command
that dereferences req->port (like in nvmet_alloc_ctrl). Those queues
should be destroyed before freeing the port via configfs. Destroy the
remaining queues after the RDMA-CM was destroyed guarantees that no
new queue will be created.

Signed-off-by: Israel Rukshin <israelr@nvidia.com>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 38d1f29..6f75e6b 100644 (file)
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -1819,12 +1819,36 @@ restart:
        mutex_unlock(&nvmet_rdma_queue_mutex);
 }
 
+static void nvmet_rdma_destroy_port_queues(struct nvmet_rdma_port *port)
+{
+       struct nvmet_rdma_queue *queue, *tmp;
+       struct nvmet_port *nport = port->nport;
+
+       mutex_lock(&nvmet_rdma_queue_mutex);
+       list_for_each_entry_safe(queue, tmp, &nvmet_rdma_queue_list,
+                                queue_list) {
+               if (queue->port != nport)
+                       continue;
+
+               list_del_init(&queue->queue_list);
+               __nvmet_rdma_queue_disconnect(queue);
+       }
+       mutex_unlock(&nvmet_rdma_queue_mutex);
+}
+
 static void nvmet_rdma_disable_port(struct nvmet_rdma_port *port)
 {
        struct rdma_cm_id *cm_id = xchg(&port->cm_id, NULL);
 
        if (cm_id)
                rdma_destroy_id(cm_id);
+
+       /*
+        * Destroy the remaining queues, which are not belong to any
+        * controller yet. Do it here after the RDMA-CM was destroyed
+        * guarantees that no new queue will be created.
+        */
+       nvmet_rdma_destroy_port_queues(port);
 }
 
 static int nvmet_rdma_enable_port(struct nvmet_rdma_port *port)