From: Logan Gunthorpe logang@deltatee.com
[ Upstream commit 86b9a63e595ff03f9d0a7b92b6acc231fecefc29 ]
After calling nvme_loop_delete_ctrl(), the controllers will not yet be deleted because nvme_delete_ctrl() only schedules work to do the delete.
This means a race can occur if a port is removed but there are still active controllers trying to access that memory.
To fix this, flush the nvme_delete_wq before returning from nvme_loop_remove_port() so that any controllers that might be in the process of being deleted won't access a freed port.
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 --- drivers/nvme/target/loop.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c index 9908082b32c4b..137a27fa369cb 100644 --- a/drivers/nvme/target/loop.c +++ b/drivers/nvme/target/loop.c @@ -678,6 +678,14 @@ static void nvme_loop_remove_port(struct nvmet_port *port) mutex_lock(&nvme_loop_ports_mutex); list_del_init(&port->entry); mutex_unlock(&nvme_loop_ports_mutex); + + /* + * Ensure any ctrls that are in the process of being + * deleted are in fact deleted before we return + * and free the port. This is to prevent active + * ctrls from using a port after it's freed. + */ + flush_workqueue(nvme_delete_wq); }
static const struct nvmet_fabrics_ops nvme_loop_ops = {