CVE-2026-23354 Linux内核x86/fred投机执行漏洞

// Conceptual PoC demonstrating the vulnerability pattern // The issue arises when the sanitized index is spilled to the stack // before the actual array access occurs. #include <linux/kernel.h> #define MAX_ARRAY_SIZE 64 // Simulated vulnerable function pattern based on the CVE description void vulnerable_fred_extint(unsigned long untrusted_user_index) { unsigned long *handler_array; unsigned long index; // 1. Sanitize the index to prevent speculative execution index = array_index_nospec(untrusted_user_index, MAX_ARRAY_SIZE); // 2. FLAW: Function call causes 'index' to be spilled to the stack // The CPU may speculate past this point using the untrusted value // before the memory writeback completes or prediction logic acts. irqentry_enter(); // 3. Access the array using the spilled index // Speculative execution might bypass the protection here handle_interrupt(handler_array[index]); }