Repository: kubernetes
Issue: device manager: potential Double-Locking of Mutex
Labels: kind/bug,sig/node,priority/important-longterm,triage/accepted

### What happened?

In the file [pod_devices.go](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/cm/devicemanager/pod_devices.go#L101), there is a potential issue of double-locking a mutex in the function `podDevices`.
- In line [102](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/cm/devicemanager/pod_devices.go#L102), the read lock (`pdev.RLock()`) is acquired in the `podDevices` function to ensure safe access to `pdev.devs`.
- Later, on line [107](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/cm/devicemanager/pod_devices.go#L107), `podDevices` calls [containerDevices](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/cm/devicemanager/pod_devices.go#L114), which also attempts to acquire the same read lock via another call to `pdev.RLock()` on line [115](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/cm/devicemanager/pod_devices.go#L115). This may result in double-locking the same mutex within the same thread.

Even though both `podDevices` and `containerDevices` only use read locks (`RLock()`), double-locking a mutex, even for reads, can lead to deadlocks, if there is another routine trying to acquire `Lock()` in between the `RLock()`s, according to the documentation of [RWMutex](https://pkg.go.dev/sync#RWMutex).

The standard `sync.Mutex()` in **Go** is not a recursive locking implementation while it is used recursively in the `podDevices` function. You can read more on why go does not implement recursive locking [here](https://groups.google.com/g/golang-nuts/c/XqW1qcuZgKg/m/Ui3nQkeLV80J).

### What did you expect to happen?

The expectation is that a mutex should not be double-locked within the same thread. In this case, either the locking logic needs to be restructured to prevent multiple acquisitions of the same lock or `containerDevices` should not attempt to lock the mutex if it is already locked by `podDevices`.

### How can we reproduce it (as minimally and precisely as possible)?

This issue is identified through static analysis, so it cannot be directly reproduced via runtime observation. However, if left unresolved, it could lead to unpredictable behavior in environments where recursive read locks are not supported.

### Anything else we need to know?

Sponsorship and Support:

This work is done by the security researchers from OpenRefactory and is supported by the [Open Source Security Foundation (OpenSSF)](https://openssf.org/): [Project Alpha-Omega](https://alpha-omega.dev/). Alpha-Omega is a project partnering with open source software project maintainers to systematically find new, as-yet-undiscovered vulnerabilities in open source code - and get them fixed – to improve global software supply chain security.

The bug is found by running the Intelligent Code Repair (iCR) tool by [OpenRefactory, Inc.](https://openrefactory.com/) and then manually triaging the results.

### Kubernetes version

<details>

```console
$ kubectl version
# paste output here
```

</details>


### Cloud provider

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### OS version

*No response*

### Install tools

*No response*

### Container runtime (CRI) and version (if applicable)

*No response*

### Related plugins (CNI, CSI, ...) and versions (if applicable)

*No response*