[PATCH 5.15 279/917] nvmet-rdma: fix use-after-free when a port is removed

Greg Kroah-Hartman
2021-11-16T00:58:43Z

From: Israel Rukshin <israelr@nvidia.com>

[ Upstream commit fcf73a804c7d6bbf0ea63531c6122aa363852e04 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/target/rdma.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)

diff --git a/drivers/nvme/target/rdma.c b/drivers/nvme/target/rdma.c
index 891174ccd44bb..f1eedbf493d5b 100644
--- a/drivers/nvme/target/rdma.c
+++ b/drivers/nvme/target/rdma.c
@@ -1818,12 +1818,36 @@ 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)
--
2.33.0