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 <errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4) #include <fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5) #include <limits.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6) #include <sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7) #include <stdarg.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8) #include <stdbool.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <stdio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <stdlib.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <sys/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <sys/stat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <sys/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <sys/vfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <unistd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #ifndef MS_NOSYMFOLLOW
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) # define MS_NOSYMFOLLOW 256     /* Do not follow symlinks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #ifndef ST_NOSYMFOLLOW
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) # define ST_NOSYMFOLLOW 0x2000  /* Do not follow symlinks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #define DATA "/tmp/data"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #define LINK "/tmp/symlink"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #define TMP  "/tmp"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) static void die(char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	va_list ap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	va_start(ap, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	vfprintf(stderr, fmt, ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	va_end(ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	exit(EXIT_FAILURE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) static void vmaybe_write_file(bool enoent_ok, char *filename, char *fmt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		va_list ap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 	ssize_t written;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	char buf[4096];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	int buf_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	buf_len = vsnprintf(buf, sizeof(buf), fmt, ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	if (buf_len < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		die("vsnprintf failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 	if (buf_len >= sizeof(buf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 		die("vsnprintf output truncated\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	fd = open(filename, O_WRONLY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	if (fd < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 		if ((errno == ENOENT) && enoent_ok)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 			return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 		die("open of %s failed: %s\n", filename, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	written = write(fd, buf, buf_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	if (written != buf_len) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 		if (written >= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 			die("short write to %s\n", filename);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 			die("write to %s failed: %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 				filename, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	if (close(fd) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		die("close of %s failed: %s\n", filename, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) static void maybe_write_file(char *filename, char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	va_list ap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	va_start(ap, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	vmaybe_write_file(true, filename, fmt, ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	va_end(ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) static void write_file(char *filename, char *fmt, ...)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	va_list ap;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	va_start(ap, fmt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	vmaybe_write_file(false, filename, fmt, ap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	va_end(ap);
^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) static void create_and_enter_ns(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	uid_t uid = getuid();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	gid_t gid = getgid();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	if (unshare(CLONE_NEWUSER) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		die("unshare(CLONE_NEWUSER) failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 	maybe_write_file("/proc/self/setgroups", "deny");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	write_file("/proc/self/uid_map", "0 %d 1", uid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	write_file("/proc/self/gid_map", "0 %d 1", gid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	if (setgid(0) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		die("setgid(0) failed %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	if (setuid(0) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		die("setuid(0) failed %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 	if (unshare(CLONE_NEWNS) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		die("unshare(CLONE_NEWNS) failed: %s\n", strerror(errno));
^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 void setup_symlink(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	int data, err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 	data = creat(DATA, O_RDWR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	if (data < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 		die("creat failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	err = symlink(DATA, LINK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 		die("symlink failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	if (close(data) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 		die("close of %s failed: %s\n", DATA, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static void test_link_traversal(bool nosymfollow)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	int link;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	link = open(LINK, 0, O_RDWR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	if (nosymfollow) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 		if ((link != -1 || errno != ELOOP)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 			die("link traversal unexpected result: %d, %s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 					link, strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 		if (link < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 			die("link traversal failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 		if (close(link) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 			die("close of link failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) static void test_readlink(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	char buf[4096];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 	ssize_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 	bzero(buf, sizeof(buf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	ret = readlink(LINK, buf, sizeof(buf));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		die("readlink failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 	if (strcmp(buf, DATA) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		die("readlink strcmp failed: '%s' '%s'\n", buf, DATA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) static void test_realpath(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	char *path = realpath(LINK, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	if (!path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		die("realpath failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	if (strcmp(path, DATA) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 		die("realpath strcmp failed\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	free(path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) static void test_statfs(bool nosymfollow)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	struct statfs buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	ret = statfs(TMP, &buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		die("statfs failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 	if (nosymfollow) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		if ((buf.f_flags & ST_NOSYMFOLLOW) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 			die("ST_NOSYMFOLLOW not set on %s\n", TMP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 		if ((buf.f_flags & ST_NOSYMFOLLOW) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 			die("ST_NOSYMFOLLOW set on %s\n", TMP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) static void run_tests(bool nosymfollow)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	test_link_traversal(nosymfollow);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	test_readlink();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	test_realpath();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	test_statfs(nosymfollow);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) int main(int argc, char **argv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	create_and_enter_ns();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	if (mount("testing", TMP, "ramfs", 0, NULL) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 		die("mount failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	setup_symlink();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	run_tests(false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	if (mount("testing", TMP, "ramfs", MS_REMOUNT|MS_NOSYMFOLLOW, NULL) != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		die("remount failed: %s\n", strerror(errno));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	run_tests(true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	return EXIT_SUCCESS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) }