CVE-2026-43292

A flaw was found in the Linux kernel. When the CONFIG_PAGE_OWNER option is enabled, the kernel's memory management (mm/vmalloc) component can experience Read-Copy-Update (RCU) stalls during virtual memory allocation cleanup. This occurs because freeing Kernel Address Sanitizer (KASAN) shadow pages triggers expensive stack unwinding operations that acquire RCU read locks. Processing a large number of pages without yielding the CPU can cause tasks to hold the CPU for extended periods, leading to RCU stalls and potential Out-Of-Memory (OOM) conditions, effectively resulting in a Denial of Service.

This vulnerability is rated as Moderate because exploitation is restricted to local access and relies on kernel debugging features that are not active in standard production environments. When specific memory diagnostics and page tracking features are engaged, releasing virtual memory structures can lead to prolonged CPU execution without preemption, triggering Read-Copy-Update stalls and potential system instability. Red Hat Enterprise Linux shipping kernels disable debug instrumentation such as KASAN by default, substantially mitigating the likelihood of impact under standard configurations.

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.