linux/drivers/nvme
Sagi Grimberg c758b77d4a nvmet: fix a possible leak when destroy a ctrl during qp establishment
In nvmet_sq_destroy we capture sq->ctrl early and if it is non-NULL we
know that a ctrl was allocated (in the admin connect request handler)
and we need to release pending AERs, clear ctrl->sqs and sq->ctrl
(for nvme-loop primarily), and drop the final reference on the ctrl.

However, a small window is possible where nvmet_sq_destroy starts (as
a result of the client giving up and disconnecting) concurrently with
the nvme admin connect cmd (which may be in an early stage). But *before*
kill_and_confirm of sq->ref (i.e. the admin connect managed to get an sq
live reference). In this case, sq->ctrl was allocated however after it was
captured in a local variable in nvmet_sq_destroy.
This prevented the final reference drop on the ctrl.

Solve this by re-capturing the sq->ctrl after all inflight request has
completed, where for sure sq->ctrl reference is final, and move forward
based on that.

This issue was observed in an environment with many hosts connecting
multiple ctrls simoutanuosly, creating a delay in allocating a ctrl
leading up to this race window.

Reported-by: Alex Turin <alex@vastdata.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
2024-05-28 10:01:52 -07:00
..
common nvme-common: add module description 2024-01-31 16:03:49 -08:00
host nvme: use srcu for iterating namespace list 2024-05-28 09:43:32 -07:00
target nvmet: fix a possible leak when destroy a ctrl during qp establishment 2024-05-28 10:01:52 -07:00
Kconfig nvme: implement In-Band authentication 2022-08-02 17:14:49 -06:00
Makefile nvme: common: make keyring and auth separate modules 2023-11-07 10:05:15 -08:00