CVE-2022-50772: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50772 is a memory leak vulnerability in the Linux kernel's netdevsim subsystem, specifically within the nsim_bus_dev_new() function. When device_register() fails, the kobject name (obj->name) allocated during dev_set_name() is not properly released, resulting in a kernel memory leak. The vulnerability was publicly disclosed on December 24, 2025, and affects Linux kernel versions prior to the patches applied in stable branches 6.0.7 and 6.1. It carries a CVSS v3.1 base score of 7.0 (High) (Red Hat Advisory, Red Hat Bugzilla).

The root cause is a missing cleanup path in the nsim_bus_dev_new() function of the Linux kernel's netdevsim driver (CWE-401: Missing Release of Memory after Effective Lifetime). When device_register() fails, the reference count on nsim_bus_dev->dev is set to 1 but the kobject name string allocated via kvasprintf during dev_set_name() is never freed. The leak is triggered via the sysfs interface — specifically by writing to the new_device bus attribute — which calls new_device_store() → device_add() → dev_set_name(), leaving a 16-byte allocation unreferenced in kernel memory. Exploitation requires local access with low privileges and high attack complexity (Red Hat Bugzilla, Red Hat Advisory).

Successful exploitation of this vulnerability results in a kernel memory leak, which can degrade system availability over time by exhausting kernel memory resources — classified as a Denial of Service (DoS) condition. The CVSS scoring also reflects potential high confidentiality and integrity impacts (score 7.0), though the primary practical impact is memory exhaustion leading to system instability or crash. The vulnerability is locally exploitable and does not directly enable remote code execution or lateral movement (Red Hat Bugzilla).

The vulnerability is patched in Linux kernel stable branches via commits 77579e4065295071fbd9662f03430dca5b50b086 (for the 6.0.x series, fixed in 6.0.7) and cf2010aa1c739bab067cbc90b690d28eaa0b47da (for the 6.1 series). Users should update to Linux kernel version 6.0.7, 6.1, or later. As a workaround, restricting unprivileged access to the netdevsim sysfs interface (e.g., via appropriate permissions or disabling the netdevsim module if not required) can reduce exposure (Red Hat Bugzilla, Red Hat Advisory).