CVE-2024-42152 nvmet: fix a possible leak when destroy a ctrl during qp establishment
A race condition in the Linux kernel NVMe target driver can cause a memory leak when destroying a controller during queue pair establishment.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-42152?
CVE-2024-42152 is a high-severity vulnerability in Linux kernel, published on 30 Jul 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-401
Which versions are affected by CVE-2024-42152?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-42152?
Apply the vendor's patch.
Is CVE-2024-42152 being exploited?
There is no known exploitation of CVE-2024-42152 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-47660, AZL-47685, BELL-CVE-2024-42152, DEBIAN-CVE-2024-42152, GHSA-ghw9-6h55-qj7v, UBUNTU-CVE-2024-42152.