CVE-2022-50495

A memory leak was found in the Linux kernel's Xen SMP interrupt initialization functions for x86 architectures. When interrupt handler binding fails during setup, the error path frees various resources but neglects to free dynamically allocated interrupt name strings created via kasprintf. This causes memory to leak with each failed initialization attempt, leading to resource exhaustion and denial of service.

The Xen SMP initialization code creates descriptive names for various inter-processor interrupts (IPIs) like reschedule, PMU, and call-function interrupts. These names are allocated dynamically using kasprintf and stored in local variables. When bind_ipi_to_irqhandler or bind_virq_to_irqhandler fails to register an interrupt handler, execution jumps to an error label that invokes xen_smp_intr_free (or xen_smp_intr_free_pv) to clean up. This cleanup releases the interrupt handlers themselves, but since the kasprintf-allocated strings were never stored in any structure that the cleanup function can access, they're simply abandoned in memory. Each initialization failure therefore leaks small amounts of memory—individually insignificant, but potentially problematic during repeated initialization cycles or in environments where Xen SMP setup repeatedly fails. The fix stores these strings where the cleanup path can find and free them.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.