[PATCH 5.15 280/917] nvmet-tcp: fix use-after-free when a port is removed

Greg Kroah-Hartman
2021-11-16T00:58:46Z

From: Israel Rukshin <israelr@nvidia.com>

[ Upstream commit 2351ead99ce9164fb42555aee3f96af84c4839e9 ]

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 accept_work was cancelled 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/tcp.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 46c3b3be7e033..84c387e4bf431 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1740,6 +1740,17 @@ err_port:
return ret;
}

+static void nvmet_tcp_destroy_port_queues(struct nvmet_tcp_port *port)
+{
+ struct nvmet_tcp_queue *queue;
+
+ mutex_lock(&nvmet_tcp_queue_mutex);
+ list_for_each_entry(queue, &nvmet_tcp_queue_list, queue_list)
+ if (queue->port == port)
+ kernel_sock_shutdown(queue->sock, SHUT_RDWR);
+ mutex_unlock(&nvmet_tcp_queue_mutex);
+}
+
static void nvmet_tcp_remove_port(struct nvmet_port *nport)
{
struct nvmet_tcp_port *port = nport->priv;
@@ -1749,6 +1760,11 @@ static void nvmet_tcp_remove_port(struct nvmet_port *nport)
port->sock->sk->sk_user_data = NULL;
write_unlock_bh(&port->sock->sk->sk_callback_lock);
cancel_work_sync(&port->accept_work);
+ /*
+ * Destroy the remaining queues, which are not belong to any
+ * controller yet.
+ */
+ nvmet_tcp_destroy_port_queues(port);

sock_release(port->sock);
kfree(port);
--
2.33.0