[PATCH 5.4 20/80] nvme-rdma: fix possible use-after-free in transport error_recovery work

Greg Kroah-Hartman
2022-02-21T09:13:01Z

From: Sagi Grimberg <sagi@grimberg.me>

[ Upstream commit b6bb1722f34bbdbabed27acdceaf585d300c5fd2 ]

While nvme_rdma_submit_async_event_work is checking the ctrl and queue
state before preparing the AER command and scheduling io_work, in order
to fully prevent a race where this check is not reliable the error
recovery work must flush async_event_work before continuing to destroy
the admin queue after setting the ctrl state to RESETTING such that
there is no race .submit_async_event and the error recovery handler
itself changing the ctrl state.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/host/rdma.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 08a23bb4b8b57..4213c71b02a4b 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1110,6 +1110,7 @@ static void nvme_rdma_error_recovery_work(struct work_struct *work)
struct nvme_rdma_ctrl, err_work);

nvme_stop_keep_alive(&ctrl->ctrl);
+ flush_work(&ctrl->ctrl.async_event_work);
nvme_rdma_teardown_io_queues(ctrl, false);
nvme_start_queues(&ctrl->ctrl);
nvme_rdma_teardown_admin_queue(ctrl, false);
--
2.34.1