[LTP] [PATCH v5 2/2] syscalls/openat: Add new regression test when using open(O_TMPFILE) under umask

[Yang Xu]

Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
---
v4->v5: add 426b4ca2d6a5 to the test tag
 runtest/syscalls                            |   2 +-
 testcases/kernel/syscalls/openat/.gitignore |   1 +
 testcases/kernel/syscalls/openat/openat04.c | 182 ++++++++++++++++++++
 3 files changed, 184 insertions(+), 1 deletion(-)
 create mode 100644 testcases/kernel/syscalls/openat/openat04.c

diff --git a/runtest/syscalls b/runtest/syscalls
index c81764df4..776a121f0 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -918,10 +918,10 @@ open12 open12
 open13 open13
 open14 open14
 
-#openat test cases
 openat01 openat01
 openat02 openat02
 openat03 openat03
+openat04 openat04
 
 openat201 openat201
 openat202 openat202
diff --git a/testcases/kernel/syscalls/openat/.gitignore b/testcases/kernel/syscalls/openat/.gitignore
index 2928dae22..2d15872ab 100644
--- a/testcases/kernel/syscalls/openat/.gitignore
+++ b/testcases/kernel/syscalls/openat/.gitignore
@@ -2,3 +2,4 @@
 /openat02
 /openat02_child
 /openat03
+/openat04
diff --git a/testcases/kernel/syscalls/openat/openat04.c b/testcases/kernel/syscalls/openat/openat04.c
new file mode 100644
index 000000000..f99911d25
--- /dev/null
+++ b/testcases/kernel/syscalls/openat/openat04.c
@@ -0,0 +1,182 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022 FUJITSU LIMITED. All rights reserved.
+ * Author: Yang Xu <xuyang2018.jy@fujitsu.com>
+ */
+
+/*\
+ * [Description]
+ *
+ * Check setgid strip logic whether works correctly when creating tmpfile under
+ * filesystem without POSIX ACL supported(by using noacl mount option). Test it
+ * with umask S_IXGRP and also check file mode whether has filtered S_IXGRP.
+ *
+ * Fixed in:
+ *
+ *  commit ac6800e279a22b28f4fc21439843025a0d5bf03e
+ *  Author: Yang Xu <xuyang2018.jy@fujitsu.com>
+ *  Date:   Thu July 14 14:11:26 2022 +0800
+ *
+ *  fs: Add missing umask strip in vfs_tmpfile
+ *
+ * The most code is pasted form creat09.c.
+ */
+
+#define _GNU_SOURCE
+#include <stdlib.h>
+#include <sys/types.h>
+#include <pwd.h>
+#include <sys/mount.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <stdio.h>
+#include "tst_test.h"
+#include "tst_uid.h"
+#include "tst_safe_file_at.h"
+
+#define MODE_RWX        0777
+#define MODE_SGID       (S_ISGID|0777)
+#define MNTPOINT	"mntpoint"
+#define WORKDIR		MNTPOINT "/testdir"
+#define OPEN_FILE	"open.tmp"
+
+static gid_t free_gid;
+static int tmpfile_fd = -1, dir_fd = -1, mount_flag;
+static struct passwd *ltpuser;
+
+static void do_mount(const char *source, const char *target,
+	const char *filesystemtype, unsigned long mountflags,
+	const void *data)
+{
+	TEST(mount(source, target, filesystemtype, mountflags, data));
+
+	if (TST_RET == -1 && TST_ERR == EINVAL)
+		tst_brk(TCONF, "Kernel does not support noacl feature");
+
+	if (TST_RET == -1) {
+		tst_brk(TBROK | TTERRNO, "mount(%s, %s, %s, %lu, %p) failed",
+			source, target, filesystemtype, mountflags, data);
+	}
+
+	if (TST_RET)
+		tst_brk(TBROK, "Invalid mount return value %ld", TST_RET);
+
+	mount_flag = 1;
+}
+
+static void open_tmpfile_supported(int dirfd)
+{
+	TEST(openat(dirfd, ".", O_TMPFILE | O_RDWR, S_IXGRP | S_ISGID));
+
+	if (TST_RET == -1) {
+		if (errno == ENOTSUP)
+			tst_brk(TCONF, "fs doesn't support O_TMPFILE");
+		else
+			tst_brk(TBROK | TTERRNO, "openat(%d, O_TMPFILE) failed", dirfd);
+	}
+
+	if (TST_RET < 0)
+		tst_brk(TBROK, "Invalid openat return value %ld", TST_RET);
+
+	SAFE_CLOSE(TST_RET);
+}
+
+static void setup(void)
+{
+	struct stat buf;
+
+	ltpuser = SAFE_GETPWNAM("nobody");
+
+	do_mount(tst_device->dev, MNTPOINT, tst_device->fs_type, 0, "noacl");
+
+	tst_res(TINFO, "User nobody: uid = %d, gid = %d", (int)ltpuser->pw_uid,
+		(int)ltpuser->pw_gid);
+	free_gid = tst_get_free_gid(ltpuser->pw_gid);
+
+	/* Create directories and set permissions */
+	SAFE_MKDIR(WORKDIR, MODE_RWX);
+	dir_fd = SAFE_OPEN(WORKDIR, O_RDONLY, O_DIRECTORY);
+	open_tmpfile_supported(dir_fd);
+
+	SAFE_CHOWN(WORKDIR, ltpuser->pw_uid, free_gid);
+	SAFE_CHMOD(WORKDIR, MODE_SGID);
+	SAFE_STAT(WORKDIR, &buf);
+
+	if (!(buf.st_mode & S_ISGID))
+		tst_brk(TBROK, "%s: Setgid bit not set", WORKDIR);
+
+	if (buf.st_gid != free_gid) {
+		tst_brk(TBROK, "%s: Incorrect group, %u != %u", WORKDIR,
+			buf.st_gid, free_gid);
+	}
+
+	/* Switch user */
+	SAFE_SETGID(ltpuser->pw_gid);
+	SAFE_SETREUID(-1, ltpuser->pw_uid);
+}
+
+static void file_test(int dfd, const char *path, int flags)
+{
+	struct stat buf;
+
+	SAFE_FSTATAT(dfd, path, &buf, flags);
+
+	TST_EXP_EQ_LI(buf.st_gid, free_gid);
+
+	if (buf.st_mode & S_ISGID)
+		tst_res(TFAIL, "%s: Setgid bit is set", path);
+	else
+		tst_res(TPASS, "%s: Setgid bit not set", path);
+
+	if (buf.st_mode & S_IXGRP)
+		tst_res(TFAIL, "%s: S_IXGRP bit is set", path);
+	else
+		tst_res(TPASS, "%s: S_IXGRP bit is not set", path);
+}
+
+static void run(void)
+{
+	char path[PATH_MAX];
+
+	umask(S_IXGRP);
+	tmpfile_fd = SAFE_OPENAT(dir_fd, ".", O_TMPFILE | O_RDWR, MODE_SGID);
+	snprintf(path, PATH_MAX, "/proc/self/fd/%d", tmpfile_fd);
+	SAFE_LINKAT(AT_FDCWD, path, dir_fd, OPEN_FILE, AT_SYMLINK_FOLLOW);
+	file_test(dir_fd, OPEN_FILE, 0);
+	SAFE_CLOSE(tmpfile_fd);
+	/* Cleanup between loops */
+	tst_purge_dir(WORKDIR);
+}
+
+static void cleanup(void)
+{
+	SAFE_SETREUID(-1, 0);
+
+	if (tmpfile_fd >= 0)
+		SAFE_CLOSE(tmpfile_fd);
+	if (dir_fd >= 0)
+		SAFE_CLOSE(dir_fd);
+	if (mount_flag && tst_umount(MNTPOINT))
+		tst_res(TWARN | TERRNO, "umount(%s)", MNTPOINT);
+}
+
+static struct tst_test test = {
+	.test_all = run,
+	.setup = setup,
+	.cleanup = cleanup,
+	.needs_root = 1,
+	.all_filesystems = 1,
+	.format_device = 1,
+	.mntpoint = MNTPOINT,
+	.skip_filesystems = (const char*[]) {
+		"exfat",
+		"ntfs",
+		"vfat",
+		NULL
+	},
+	.tags = (const struct tst_tag[]) {
+		{"linux-git", "ac6800e279a2"},
+		{"linux-git", "426b4ca2d6a5"},
+		{}
+	},
+};
-- 
2.23.0