CVE-2022-50748

Vulnerability

Description A memory leak occurs in the Linux kernel's init_mqueue_fs() function during filesystem initialization for POSIX message queues. The function calls setup_mq_sysctls() to allocate sysctl tables, but if a subsequent step fails, the allocated sysctl structures are not freed. This mirrors a previously fixed leak in the ipc namespace creation path [1].

Exploitation

Conditions No special privileges or network access are required for the bug to manifest—it triggers during kernel boot or module loading when the mqueue filesystem is initialized. An attacker would need the ability to cause the initialization to fail (e.g., by exhausting kernel memory), but the primary risk is a system-level memory leak that degrades availability over time.

Impact

The leak gradually consumes kernel memory, potentially leading to resource exhaustion and denial of service. Under sustained trigger conditions, the system may become unresponsive or crash. There is no data confidentiality or integrity impact.

Mitigation

The fix has been merged into the stable kernel tree [1]. Systems running kernels prior to the patch are vulnerable; updating to a patched version resolves the issue. No workarounds are documented.