nvmet: Fix use-after-free bug when a port is removed

[ Upstream commit 3aed86731ee2b23e4dc4d2c6d943d33992cd551b ]

When a port is removed through configfs, any connected controllers
are still active and can still send commands. This causes a
use-after-free bug which is detected by KASAN for any admin command
that dereferences req->port (like in nvmet_execute_identify_ctrl).

To fix this, disconnect all active controllers when a subsystem is
removed from a port. This ensures there are no active controllers
when the port is eventually removed.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by : Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/nvme/target/configfs.c b/drivers/nvme/target/configfs.c
index 08dd5af357f7c599587e760bc7c18c1c41c8ce8b..3854363118ccfe6491f45f7e06b67b02a4c77df0 100644 (file)
--- a/drivers/nvme/target/configfs.c
+++ b/drivers/nvme/target/configfs.c
@@ -673,6 +673,7 @@ static void nvmet_port_subsys_drop_link(struct config_item *parent,
 
 found:
        list_del(&p->entry);
+       nvmet_port_del_ctrls(port, subsys);
        nvmet_port_disc_changed(port, subsys);
 
        if (list_empty(&port->subsystems))

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index 7734a6acff85182feade6f394f1cb2829c9397c7..e4db9a44116813171bb1cfff62da6a78be033be9 100644 (file)
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -277,6 +277,18 @@ void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops)
 }
 EXPORT_SYMBOL_GPL(nvmet_unregister_transport);
 
+void nvmet_port_del_ctrls(struct nvmet_port *port, struct nvmet_subsys *subsys)
+{
+       struct nvmet_ctrl *ctrl;
+
+       mutex_lock(&subsys->lock);
+       list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) {
+               if (ctrl->port == port)
+                       ctrl->ops->delete_ctrl(ctrl);
+       }
+       mutex_unlock(&subsys->lock);
+}
+
 int nvmet_enable_port(struct nvmet_port *port)
 {
        const struct nvmet_fabrics_ops *ops;

diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index c25d88fc9dec82ade67859fc35df33260ce4f35f..b6b0d483e0c50904b99213adc790d4c1a47acb44 100644 (file)
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -415,6 +415,9 @@ void nvmet_port_send_ana_event(struct nvmet_port *port);
 int nvmet_register_transport(const struct nvmet_fabrics_ops *ops);
 void nvmet_unregister_transport(const struct nvmet_fabrics_ops *ops);
 
+void nvmet_port_del_ctrls(struct nvmet_port *port,
+                         struct nvmet_subsys *subsys);
+
 int nvmet_enable_port(struct nvmet_port *port);
 void nvmet_disable_port(struct nvmet_port *port);