162306a36Sopenharmony_ci// SPDX-License-Identifier: GPL-2.0 262306a36Sopenharmony_ci#define _GNU_SOURCE 362306a36Sopenharmony_ci#include <sched.h> 462306a36Sopenharmony_ci#include <unistd.h> 562306a36Sopenharmony_ci#include <stdio.h> 662306a36Sopenharmony_ci#include <stdlib.h> 762306a36Sopenharmony_ci#include <signal.h> 862306a36Sopenharmony_ci#include <errno.h> 962306a36Sopenharmony_ci#include <sys/types.h> 1062306a36Sopenharmony_ci#include <sys/stat.h> 1162306a36Sopenharmony_ci#include <fcntl.h> 1262306a36Sopenharmony_ci#include <sys/ioctl.h> 1362306a36Sopenharmony_ci#include <sys/prctl.h> 1462306a36Sopenharmony_ci#include <sys/wait.h> 1562306a36Sopenharmony_ci 1662306a36Sopenharmony_ci#define pr_err(fmt, ...) \ 1762306a36Sopenharmony_ci ({ \ 1862306a36Sopenharmony_ci fprintf(stderr, "%s:%d:" fmt ": %m\n", \ 1962306a36Sopenharmony_ci __func__, __LINE__, ##__VA_ARGS__); \ 2062306a36Sopenharmony_ci 1; \ 2162306a36Sopenharmony_ci }) 2262306a36Sopenharmony_ci 2362306a36Sopenharmony_ci#define NSIO 0xb7 2462306a36Sopenharmony_ci#define NS_GET_USERNS _IO(NSIO, 0x1) 2562306a36Sopenharmony_ci#define NS_GET_PARENT _IO(NSIO, 0x2) 2662306a36Sopenharmony_ci 2762306a36Sopenharmony_ci#define __stack_aligned__ __attribute__((aligned(16))) 2862306a36Sopenharmony_cistruct cr_clone_arg { 2962306a36Sopenharmony_ci char stack[128] __stack_aligned__; 3062306a36Sopenharmony_ci char stack_ptr[]; 3162306a36Sopenharmony_ci}; 3262306a36Sopenharmony_ci 3362306a36Sopenharmony_cistatic int child(void *args) 3462306a36Sopenharmony_ci{ 3562306a36Sopenharmony_ci prctl(PR_SET_PDEATHSIG, SIGKILL); 3662306a36Sopenharmony_ci while (1) 3762306a36Sopenharmony_ci sleep(1); 3862306a36Sopenharmony_ci exit(0); 3962306a36Sopenharmony_ci} 4062306a36Sopenharmony_ci 4162306a36Sopenharmony_ciint main(int argc, char *argv[]) 4262306a36Sopenharmony_ci{ 4362306a36Sopenharmony_ci char *ns_strs[] = {"pid", "user"}; 4462306a36Sopenharmony_ci char path[] = "/proc/0123456789/ns/pid"; 4562306a36Sopenharmony_ci struct cr_clone_arg ca; 4662306a36Sopenharmony_ci struct stat st1, st2; 4762306a36Sopenharmony_ci int ns, pns, i; 4862306a36Sopenharmony_ci pid_t pid; 4962306a36Sopenharmony_ci 5062306a36Sopenharmony_ci pid = clone(child, ca.stack_ptr, CLONE_NEWUSER | CLONE_NEWPID | SIGCHLD, NULL); 5162306a36Sopenharmony_ci if (pid < 0) 5262306a36Sopenharmony_ci return pr_err("clone"); 5362306a36Sopenharmony_ci 5462306a36Sopenharmony_ci for (i = 0; i < 2; i++) { 5562306a36Sopenharmony_ci snprintf(path, sizeof(path), "/proc/%d/ns/%s", pid, ns_strs[i]); 5662306a36Sopenharmony_ci ns = open(path, O_RDONLY); 5762306a36Sopenharmony_ci if (ns < 0) 5862306a36Sopenharmony_ci return pr_err("Unable to open %s", path); 5962306a36Sopenharmony_ci 6062306a36Sopenharmony_ci pns = ioctl(ns, NS_GET_PARENT); 6162306a36Sopenharmony_ci if (pns < 0) 6262306a36Sopenharmony_ci return pr_err("Unable to get a parent pidns"); 6362306a36Sopenharmony_ci 6462306a36Sopenharmony_ci snprintf(path, sizeof(path), "/proc/self/ns/%s", ns_strs[i]); 6562306a36Sopenharmony_ci if (stat(path, &st2)) 6662306a36Sopenharmony_ci return pr_err("Unable to stat %s", path); 6762306a36Sopenharmony_ci if (fstat(pns, &st1)) 6862306a36Sopenharmony_ci return pr_err("Unable to stat the parent pidns"); 6962306a36Sopenharmony_ci if (st1.st_ino != st2.st_ino) 7062306a36Sopenharmony_ci return pr_err("NS_GET_PARENT returned a wrong namespace"); 7162306a36Sopenharmony_ci 7262306a36Sopenharmony_ci if (ioctl(pns, NS_GET_PARENT) >= 0 || errno != EPERM) 7362306a36Sopenharmony_ci return pr_err("Don't get EPERM"); 7462306a36Sopenharmony_ci } 7562306a36Sopenharmony_ci 7662306a36Sopenharmony_ci kill(pid, SIGKILL); 7762306a36Sopenharmony_ci wait(NULL); 7862306a36Sopenharmony_ci return 0; 7962306a36Sopenharmony_ci} 80