Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) #define _GNU_SOURCE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3) #include <sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) #include <stdio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) #include <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <sys/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <sys/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <sys/wait.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <sys/vfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <sys/statvfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <stdlib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <grp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <stdbool.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <stdarg.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #ifndef CLONE_NEWNS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) # define CLONE_NEWNS 0x00020000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #ifndef CLONE_NEWUTS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) # define CLONE_NEWUTS 0x04000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #ifndef CLONE_NEWIPC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) # define CLONE_NEWIPC 0x08000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #ifndef CLONE_NEWNET
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) # define CLONE_NEWNET 0x40000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) #ifndef CLONE_NEWUSER
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) # define CLONE_NEWUSER 0x10000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) #ifndef CLONE_NEWPID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) # define CLONE_NEWPID 0x20000000
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) #ifndef MS_REC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) # define MS_REC 16384
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) #ifndef MS_RELATIME
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) # define MS_RELATIME (1 << 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) #ifndef MS_STRICTATIME
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) # define MS_STRICTATIME (1 << 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) static void die(char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 	va_list ap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	va_start(ap, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	vfprintf(stderr, fmt, ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	va_end(ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 	exit(EXIT_FAILURE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) static void vmaybe_write_file(bool enoent_ok, char *filename, char *fmt, va_list ap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	char buf[4096];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	ssize_t written;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	int buf_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	buf_len = vsnprintf(buf, sizeof(buf), fmt, ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (buf_len < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		die("vsnprintf failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 		    strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	if (buf_len >= sizeof(buf)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 		die("vsnprintf output truncated\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	fd = open(filename, O_WRONLY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	if (fd < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		if ((errno == ENOENT) && enoent_ok)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 		die("open of %s failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		    filename, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	written = write(fd, buf, buf_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	if (written != buf_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		if (written >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 			die("short write to %s\n", filename);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 			die("write to %s failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 				filename, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	if (close(fd) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		die("close of %s failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 			filename, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) static void maybe_write_file(char *filename, char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	va_list ap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	va_start(ap, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	vmaybe_write_file(true, filename, fmt, ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	va_end(ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) static void write_file(char *filename, char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	va_list ap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	va_start(ap, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 	vmaybe_write_file(false, filename, fmt, ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	va_end(ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) static int read_mnt_flags(const char *path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	struct statvfs stat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	int mnt_flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	ret = statvfs(path, &stat);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	if (ret != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 		die("statvfs of %s failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 			path, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	if (stat.f_flag & ~(ST_RDONLY | ST_NOSUID | ST_NODEV | \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 			ST_NOEXEC | ST_NOATIME | ST_NODIRATIME | ST_RELATIME | \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 			ST_SYNCHRONOUS | ST_MANDLOCK)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		die("Unrecognized mount flags\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	mnt_flags = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	if (stat.f_flag & ST_RDONLY)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 		mnt_flags |= MS_RDONLY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	if (stat.f_flag & ST_NOSUID)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		mnt_flags |= MS_NOSUID;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	if (stat.f_flag & ST_NODEV)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 		mnt_flags |= MS_NODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	if (stat.f_flag & ST_NOEXEC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		mnt_flags |= MS_NOEXEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 	if (stat.f_flag & ST_NOATIME)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 		mnt_flags |= MS_NOATIME;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	if (stat.f_flag & ST_NODIRATIME)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 		mnt_flags |= MS_NODIRATIME;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	if (stat.f_flag & ST_RELATIME)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 		mnt_flags |= MS_RELATIME;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	if (stat.f_flag & ST_SYNCHRONOUS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 		mnt_flags |= MS_SYNCHRONOUS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	if (stat.f_flag & ST_MANDLOCK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		mnt_flags |= ST_MANDLOCK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	return mnt_flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) static void create_and_enter_userns(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	uid_t uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	gid_t gid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	uid = getuid();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	gid = getgid();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	if (unshare(CLONE_NEWUSER) !=0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		die("unshare(CLONE_NEWUSER) failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 			strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	maybe_write_file("/proc/self/setgroups", "deny");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	write_file("/proc/self/uid_map", "0 %d 1", uid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	write_file("/proc/self/gid_map", "0 %d 1", gid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	if (setgid(0) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		die ("setgid(0) failed %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 			strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	if (setuid(0) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		die("setuid(0) failed %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 			strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) bool test_unpriv_remount(const char *fstype, const char *mount_options,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 			 int mount_flags, int remount_flags, int invalid_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	pid_t child;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	child = fork();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	if (child == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		die("fork failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 			strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	if (child != 0) { /* parent */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 		pid_t pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 		int status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 		pid = waitpid(child, &status, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		if (pid == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 			die("waitpid failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 				strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		if (pid != child) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 			die("waited for %d got %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 				child, pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 		if (!WIFEXITED(status)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 			die("child did not terminate cleanly\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 		return WEXITSTATUS(status) == EXIT_SUCCESS ? true : false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	create_and_enter_userns();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	if (unshare(CLONE_NEWNS) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		die("unshare(CLONE_NEWNS) failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 			strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	if (mount("testing", "/tmp", fstype, mount_flags, mount_options) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 		die("mount of %s with options '%s' on /tmp failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		    fstype,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 		    mount_options? mount_options : "",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		    strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	create_and_enter_userns();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	if (unshare(CLONE_NEWNS) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 		die("unshare(CLONE_NEWNS) failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 			strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	if (mount("/tmp", "/tmp", "none",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 		  MS_REMOUNT | MS_BIND | remount_flags, NULL) != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 		/* system("cat /proc/self/mounts"); */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 		die("remount of /tmp failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 		    strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	if (mount("/tmp", "/tmp", "none",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 		  MS_REMOUNT | MS_BIND | invalid_flags, NULL) == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 		/* system("cat /proc/self/mounts"); */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 		die("remount of /tmp with invalid flags "
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 		    "succeeded unexpectedly\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	exit(EXIT_SUCCESS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) static bool test_unpriv_remount_simple(int mount_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	return test_unpriv_remount("ramfs", NULL, mount_flags, mount_flags, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) static bool test_unpriv_remount_atime(int mount_flags, int invalid_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	return test_unpriv_remount("ramfs", NULL, mount_flags, mount_flags,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 				   invalid_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) static bool test_priv_mount_unpriv_remount(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 	pid_t child;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	const char *orig_path = "/dev";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	const char *dest_path = "/tmp";
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	int orig_mnt_flags, remount_mnt_flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	child = fork();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	if (child == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 		die("fork failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 			strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	if (child != 0) { /* parent */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 		pid_t pid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 		int status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 		pid = waitpid(child, &status, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 		if (pid == -1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 			die("waitpid failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 				strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 		if (pid != child) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 			die("waited for %d got %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 				child, pid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 		if (!WIFEXITED(status)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 			die("child did not terminate cleanly\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 		return WEXITSTATUS(status) == EXIT_SUCCESS ? true : false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	orig_mnt_flags = read_mnt_flags(orig_path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	create_and_enter_userns();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	ret = unshare(CLONE_NEWNS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 	if (ret != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 		die("unshare(CLONE_NEWNS) failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 			strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	ret = mount(orig_path, dest_path, "bind", MS_BIND | MS_REC, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 	if (ret != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 		die("recursive bind mount of %s onto %s failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 			orig_path, dest_path, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 	ret = mount(dest_path, dest_path, "none",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 		    MS_REMOUNT | MS_BIND | orig_mnt_flags , NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	if (ret != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 		/* system("cat /proc/self/mounts"); */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 		die("remount of /tmp failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 		    strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 	remount_mnt_flags = read_mnt_flags(dest_path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 	if (orig_mnt_flags != remount_mnt_flags) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 		die("Mount flags unexpectedly changed during remount of %s originally mounted on %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 			dest_path, orig_path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 	exit(EXIT_SUCCESS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) int main(int argc, char **argv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 	if (!test_unpriv_remount_simple(MS_RDONLY)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 		die("MS_RDONLY malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 	if (!test_unpriv_remount("devpts", "newinstance", MS_NODEV, MS_NODEV, 0)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 		die("MS_NODEV malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 	if (!test_unpriv_remount_simple(MS_NOSUID)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 		die("MS_NOSUID malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 	if (!test_unpriv_remount_simple(MS_NOEXEC)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 		die("MS_NOEXEC malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	if (!test_unpriv_remount_atime(MS_RELATIME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 				       MS_NOATIME))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 		die("MS_RELATIME malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 	if (!test_unpriv_remount_atime(MS_STRICTATIME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 				       MS_NOATIME))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 		die("MS_STRICTATIME malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	if (!test_unpriv_remount_atime(MS_NOATIME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 				       MS_STRICTATIME))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 		die("MS_NOATIME malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 	if (!test_unpriv_remount_atime(MS_RELATIME|MS_NODIRATIME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 				       MS_NOATIME))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 		die("MS_RELATIME|MS_NODIRATIME malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 	if (!test_unpriv_remount_atime(MS_STRICTATIME|MS_NODIRATIME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 				       MS_NOATIME))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 		die("MS_STRICTATIME|MS_NODIRATIME malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 	if (!test_unpriv_remount_atime(MS_NOATIME|MS_NODIRATIME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 				       MS_STRICTATIME))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 		die("MS_NOATIME|MS_DIRATIME malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	if (!test_unpriv_remount("ramfs", NULL, MS_STRICTATIME, 0, MS_NOATIME))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 		die("Default atime malfunctions\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 	if (!test_priv_mount_unpriv_remount()) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 		die("Mount flags unexpectedly changed after remount\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 	return EXIT_SUCCESS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) }