* Copyright (c) International Business Machines Corp., 2001
* 07/2001 Ported by Wayne Boyer
* Copyright (c) 2025 SUSE LLC Ricardo B. Marlière <rbm@suse.com>
*/
* Verify that mknod(2) succeeds when used to create a filesystem node on a
* directory with set-group-ID bit set. The node created should not have
* set-group-ID bit set and its gid should be equal to the effective
* gid of the process.
*/
#include <pwd.h>
#include "tst_uid.h"
#include "tst_test.h"
#define MODE_RWX 0777
#define MODE_FIFO (S_IFIFO | 0777)
#define MODE_FIFO_SGID (S_IFIFO | S_ISGID | 0777)
#define TEMP_DIR "testdir"
#define TEMP_NODE TEMP_DIR "/testnode"
static uid_t nobody_uid;
static gid_t nobody_gid, free_gid;
static void run(void)
{
struct stat buf;
SAFE_MKNOD(TEMP_NODE, MODE_FIFO, 0);
SAFE_STAT(TEMP_NODE, &buf);
TST_EXP_EQ_LI(buf.st_mode & S_ISGID, 0);
TST_EXP_EQ_LI(buf.st_gid, free_gid);
SAFE_UNLINK(TEMP_NODE);
}
static void setup(void)
{
struct passwd *ltpuser = SAFE_GETPWNAM("nobody");
nobody_uid = ltpuser->pw_uid;
nobody_gid = ltpuser->pw_gid;
free_gid = tst_get_free_gid(nobody_gid);
SAFE_MKDIR(TEMP_DIR, MODE_RWX);
SAFE_CHOWN(TEMP_DIR, nobody_uid, free_gid);
SAFE_CHMOD(TEMP_DIR, MODE_FIFO_SGID);
SAFE_SETGID(nobody_gid);
SAFE_SETREUID(-1, nobody_uid);
}
static struct tst_test test = {
.setup = setup,
.test_all = run,
.needs_root = 1,
.needs_tmpdir = 1,
};