CVE-2022-50761

Vulnerability

Details

The vulnerability is a memory leak in the xen_init_lock_cpu() function in the Linux kernel's x86/xen subsystem. The function uses kasprintf() to allocate a string for the name. If the subsequent call to bind_ipi_to_irqhandler() fails, the allocated string is not freed, resulting in a memory leak.

Exploitation

To exploit this, an attacker must be able to trigger a failure in bind_ipi_to_irqhandler() during CPU initialization in a Xen environment. This may require specific system conditions or a crafted configuration. No special privileges are explicitly required, but the attack vector is likely local.

Impact

The memory leak can gradually exhaust kernel memory, potentially leading to system instability or denial of service. There is no indication of code execution or privilege escalation.

Mitigation

The fix involves freeing the allocated string in the error path. Patches have been applied to stable kernel branches [1][2][3]. Users should update to patched kernels.