CVE Published: 30/07/2024 |
CVE Updated: 05/11/2024 |
CVE Year: 2024 Source: Linux |
Vendor: Linux |
Product: Linux Status : PUBLISHED
CVE-2024-42152 Description
In the Linux kernel, the following vulnerability has been resolved:
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.