Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 523 insertions, 0 deletions

diff --git a/tools/testing/selftests/openat2/resolve_test.c b/tools/testing/selftests/openat2/resolve_test.c
new file mode 100644
index 000000000..bbafad440
--- /dev/null
+++ b/tools/testing/selftests/openat2/resolve_test.c
@@ -0,0 +1,523 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author: Aleksa Sarai <cyphar@cyphar.com>
+ * Copyright (C) 2018-2019 SUSE LLC.
+ */
+
+#define _GNU_SOURCE
+#include <fcntl.h>
+#include <sched.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/mount.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include "../kselftest.h"
+#include "helpers.h"
+
+/*
+ * Construct a test directory with the following structure:
+ *
+ * root/
+ * |-- procexe -> /proc/self/exe
+ * |-- procroot -> /proc/self/root
+ * |-- root/
+ * |-- mnt/ [mountpoint]
+ * |   |-- self -> ../mnt/
+ * |   `-- absself -> /mnt/
+ * |-- etc/
+ * |   `-- passwd
+ * |-- creatlink -> /newfile3
+ * |-- reletc -> etc/
+ * |-- relsym -> etc/passwd
+ * |-- absetc -> /etc/
+ * |-- abssym -> /etc/passwd
+ * |-- abscheeky -> /cheeky
+ * `-- cheeky/
+ *     |-- absself -> /
+ *     |-- self -> ../../root/
+ *     |-- garbageself -> /../../root/
+ *     |-- passwd -> ../cheeky/../cheeky/../etc/../etc/passwd
+ *     |-- abspasswd -> /../cheeky/../cheeky/../etc/../etc/passwd
+ *     |-- dotdotlink -> ../../../../../../../../../../../../../../etc/passwd
+ *     `-- garbagelink -> /../../../../../../../../../../../../../../etc/passwd
+ */
+int setup_testdir(void)
+{
+	int dfd, tmpfd;
+	char dirname[] = "/tmp/ksft-openat2-testdir.XXXXXX";
+
+	/* Unshare and make /tmp a new directory. */
+	E_unshare(CLONE_NEWNS);
+	E_mount("", "/tmp", "", MS_PRIVATE, "");
+
+	/* Make the top-level directory. */
+	if (!mkdtemp(dirname))
+		ksft_exit_fail_msg("setup_testdir: failed to create tmpdir\n");
+	dfd = open(dirname, O_PATH | O_DIRECTORY);
+	if (dfd < 0)
+		ksft_exit_fail_msg("setup_testdir: failed to open tmpdir\n");
+
+	/* A sub-directory which is actually used for tests. */
+	E_mkdirat(dfd, "root", 0755);
+	tmpfd = openat(dfd, "root", O_PATH | O_DIRECTORY);
+	if (tmpfd < 0)
+		ksft_exit_fail_msg("setup_testdir: failed to open tmpdir\n");
+	close(dfd);
+	dfd = tmpfd;
+
+	E_symlinkat("/proc/self/exe", dfd, "procexe");
+	E_symlinkat("/proc/self/root", dfd, "procroot");
+	E_mkdirat(dfd, "root", 0755);
+
+	/* There is no mountat(2), so use chdir. */
+	E_mkdirat(dfd, "mnt", 0755);
+	E_fchdir(dfd);
+	E_mount("tmpfs", "./mnt", "tmpfs", MS_NOSUID | MS_NODEV, "");
+	E_symlinkat("../mnt/", dfd, "mnt/self");
+	E_symlinkat("/mnt/", dfd, "mnt/absself");
+
+	E_mkdirat(dfd, "etc", 0755);
+	E_touchat(dfd, "etc/passwd");
+
+	E_symlinkat("/newfile3", dfd, "creatlink");
+	E_symlinkat("etc/", dfd, "reletc");
+	E_symlinkat("etc/passwd", dfd, "relsym");
+	E_symlinkat("/etc/", dfd, "absetc");
+	E_symlinkat("/etc/passwd", dfd, "abssym");
+	E_symlinkat("/cheeky", dfd, "abscheeky");
+
+	E_mkdirat(dfd, "cheeky", 0755);
+
+	E_symlinkat("/", dfd, "cheeky/absself");
+	E_symlinkat("../../root/", dfd, "cheeky/self");
+	E_symlinkat("/../../root/", dfd, "cheeky/garbageself");
+
+	E_symlinkat("../cheeky/../etc/../etc/passwd", dfd, "cheeky/passwd");
+	E_symlinkat("/../cheeky/../etc/../etc/passwd", dfd, "cheeky/abspasswd");
+
+	E_symlinkat("../../../../../../../../../../../../../../etc/passwd",
+		    dfd, "cheeky/dotdotlink");
+	E_symlinkat("/../../../../../../../../../../../../../../etc/passwd",
+		    dfd, "cheeky/garbagelink");
+
+	return dfd;
+}
+
+struct basic_test {
+	const char *name;
+	const char *dir;
+	const char *path;
+	struct open_how how;
+	bool pass;
+	union {
+		int err;
+		const char *path;
+	} out;
+};
+
+#define NUM_OPENAT2_OPATH_TESTS 88
+
+void test_openat2_opath_tests(void)
+{
+	int rootfd, hardcoded_fd;
+	char *procselfexe, *hardcoded_fdpath;
+
+	E_asprintf(&procselfexe, "/proc/%d/exe", getpid());
+	rootfd = setup_testdir();
+
+	hardcoded_fd = open("/dev/null", O_RDONLY);
+	E_assert(hardcoded_fd >= 0, "open fd to hardcode");
+	E_asprintf(&hardcoded_fdpath, "self/fd/%d", hardcoded_fd);
+
+	struct basic_test tests[] = {
+		/** RESOLVE_BENEATH **/
+		/* Attempts to cross dirfd should be blocked. */
+		{ .name = "[beneath] jump to /",
+		  .path = "/",			.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] absolute link to $root",
+		  .path = "cheeky/absself",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] chained absolute links to $root",
+		  .path = "abscheeky/absself",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] jump outside $root",
+		  .path = "..",			.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] temporary jump outside $root",
+		  .path = "../root/",		.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] symlink temporary jump outside $root",
+		  .path = "cheeky/self",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] chained symlink temporary jump outside $root",
+		  .path = "abscheeky/self",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] garbage links to $root",
+		  .path = "cheeky/garbageself",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] chained garbage links to $root",
+		  .path = "abscheeky/garbageself", .how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		/* Only relative paths that stay inside dirfd should work. */
+		{ .name = "[beneath] ordinary path to 'root'",
+		  .path = "root",		.how.resolve = RESOLVE_BENEATH,
+		  .out.path = "root",		.pass = true },
+		{ .name = "[beneath] ordinary path to 'etc'",
+		  .path = "etc",		.how.resolve = RESOLVE_BENEATH,
+		  .out.path = "etc",		.pass = true },
+		{ .name = "[beneath] ordinary path to 'etc/passwd'",
+		  .path = "etc/passwd",		.how.resolve = RESOLVE_BENEATH,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[beneath] relative symlink inside $root",
+		  .path = "relsym",		.how.resolve = RESOLVE_BENEATH,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[beneath] chained-'..' relative symlink inside $root",
+		  .path = "cheeky/passwd",	.how.resolve = RESOLVE_BENEATH,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[beneath] absolute symlink component outside $root",
+		  .path = "abscheeky/passwd",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] absolute symlink target outside $root",
+		  .path = "abssym",		.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] absolute path outside $root",
+		  .path = "/etc/passwd",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] cheeky absolute path outside $root",
+		  .path = "cheeky/abspasswd",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] chained cheeky absolute path outside $root",
+		  .path = "abscheeky/abspasswd", .how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		/* Tricky paths should fail. */
+		{ .name = "[beneath] tricky '..'-chained symlink outside $root",
+		  .path = "cheeky/dotdotlink",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] tricky absolute + '..'-chained symlink outside $root",
+		  .path = "abscheeky/dotdotlink", .how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] tricky garbage link outside $root",
+		  .path = "cheeky/garbagelink",	.how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[beneath] tricky absolute + garbage link outside $root",
+		  .path = "abscheeky/garbagelink", .how.resolve = RESOLVE_BENEATH,
+		  .out.err = -EXDEV,		.pass = false },
+
+		/** RESOLVE_IN_ROOT **/
+		/* All attempts to cross the dirfd will be scoped-to-root. */
+		{ .name = "[in_root] jump to /",
+		  .path = "/",			.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = NULL,		.pass = true },
+		{ .name = "[in_root] absolute symlink to /root",
+		  .path = "cheeky/absself",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = NULL,		.pass = true },
+		{ .name = "[in_root] chained absolute symlinks to /root",
+		  .path = "abscheeky/absself",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = NULL,		.pass = true },
+		{ .name = "[in_root] '..' at root",
+		  .path = "..",			.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = NULL,		.pass = true },
+		{ .name = "[in_root] '../root' at root",
+		  .path = "../root/",		.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "root",		.pass = true },
+		{ .name = "[in_root] relative symlink containing '..' above root",
+		  .path = "cheeky/self",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "root",		.pass = true },
+		{ .name = "[in_root] garbage link to /root",
+		  .path = "cheeky/garbageself",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "root",		.pass = true },
+		{ .name = "[in_root] chained garbage links to /root",
+		  .path = "abscheeky/garbageself", .how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "root",		.pass = true },
+		{ .name = "[in_root] relative path to 'root'",
+		  .path = "root",		.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "root",		.pass = true },
+		{ .name = "[in_root] relative path to 'etc'",
+		  .path = "etc",		.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc",		.pass = true },
+		{ .name = "[in_root] relative path to 'etc/passwd'",
+		  .path = "etc/passwd",		.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] relative symlink to 'etc/passwd'",
+		  .path = "relsym",		.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] chained-'..' relative symlink to 'etc/passwd'",
+		  .path = "cheeky/passwd",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] chained-'..' absolute + relative symlink to 'etc/passwd'",
+		  .path = "abscheeky/passwd",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] absolute symlink to 'etc/passwd'",
+		  .path = "abssym",		.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] absolute path 'etc/passwd'",
+		  .path = "/etc/passwd",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] cheeky absolute path 'etc/passwd'",
+		  .path = "cheeky/abspasswd",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] chained cheeky absolute path 'etc/passwd'",
+		  .path = "abscheeky/abspasswd", .how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] tricky '..'-chained symlink outside $root",
+		  .path = "cheeky/dotdotlink",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] tricky absolute + '..'-chained symlink outside $root",
+		  .path = "abscheeky/dotdotlink", .how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] tricky absolute path + absolute + '..'-chained symlink outside $root",
+		  .path = "/../../../../abscheeky/dotdotlink", .how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] tricky garbage link outside $root",
+		  .path = "cheeky/garbagelink",	.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] tricky absolute + garbage link outside $root",
+		  .path = "abscheeky/garbagelink", .how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		{ .name = "[in_root] tricky absolute path + absolute + garbage link outside $root",
+		  .path = "/../../../../abscheeky/garbagelink", .how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "etc/passwd",	.pass = true },
+		/* O_CREAT should handle trailing symlinks correctly. */
+		{ .name = "[in_root] O_CREAT of relative path inside $root",
+		  .path = "newfile1",		.how.flags = O_CREAT,
+						.how.mode = 0700,
+						.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "newfile1",	.pass = true },
+		{ .name = "[in_root] O_CREAT of absolute path",
+		  .path = "/newfile2",		.how.flags = O_CREAT,
+						.how.mode = 0700,
+						.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "newfile2",	.pass = true },
+		{ .name = "[in_root] O_CREAT of tricky symlink outside root",
+		  .path = "/creatlink",		.how.flags = O_CREAT,
+						.how.mode = 0700,
+						.how.resolve = RESOLVE_IN_ROOT,
+		  .out.path = "newfile3",	.pass = true },
+
+		/** RESOLVE_NO_XDEV **/
+		/* Crossing *down* into a mountpoint is disallowed. */
+		{ .name = "[no_xdev] cross into $mnt",
+		  .path = "mnt",		.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[no_xdev] cross into $mnt/",
+		  .path = "mnt/",		.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[no_xdev] cross into $mnt/.",
+		  .path = "mnt/.",		.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		/* Crossing *up* out of a mountpoint is disallowed. */
+		{ .name = "[no_xdev] goto mountpoint root",
+		  .dir = "mnt", .path = ".",	.how.resolve = RESOLVE_NO_XDEV,
+		  .out.path = "mnt",		.pass = true },
+		{ .name = "[no_xdev] cross up through '..'",
+		  .dir = "mnt", .path = "..",	.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[no_xdev] temporary cross up through '..'",
+		  .dir = "mnt", .path = "../mnt", .how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[no_xdev] temporary relative symlink cross up",
+		  .dir = "mnt", .path = "self",	.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[no_xdev] temporary absolute symlink cross up",
+		  .dir = "mnt", .path = "absself", .how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		/* Jumping to "/" is ok, but later components cannot cross. */
+		{ .name = "[no_xdev] jump to / directly",
+		  .dir = "mnt", .path = "/",	.how.resolve = RESOLVE_NO_XDEV,
+		  .out.path = "/",		.pass = true },
+		{ .name = "[no_xdev] jump to / (from /) directly",
+		  .dir = "/", .path = "/",	.how.resolve = RESOLVE_NO_XDEV,
+		  .out.path = "/",		.pass = true },
+		{ .name = "[no_xdev] jump to / then proc",
+		  .path = "/proc/1",		.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		{ .name = "[no_xdev] jump to / then tmp",
+		  .path = "/tmp",		.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,		.pass = false },
+		/* Magic-links are blocked since they can switch vfsmounts. */
+		{ .name = "[no_xdev] cross through magic-link to self/root",
+		  .dir = "/proc", .path = "self/root", 	.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,			.pass = false },
+		{ .name = "[no_xdev] cross through magic-link to self/cwd",
+		  .dir = "/proc", .path = "self/cwd",	.how.resolve = RESOLVE_NO_XDEV,
+		  .out.err = -EXDEV,			.pass = false },
+		/* Except magic-link jumps inside the same vfsmount. */
+		{ .name = "[no_xdev] jump through magic-link to same procfs",
+		  .dir = "/proc", .path = hardcoded_fdpath, .how.resolve = RESOLVE_NO_XDEV,
+		  .out.path = "/proc",			    .pass = true, },
+
+		/** RESOLVE_NO_MAGICLINKS **/
+		/* Regular symlinks should work. */
+		{ .name = "[no_magiclinks] ordinary relative symlink",
+		  .path = "relsym",		.how.resolve = RESOLVE_NO_MAGICLINKS,
+		  .out.path = "etc/passwd",	.pass = true },
+		/* Magic-links should not work. */
+		{ .name = "[no_magiclinks] symlink to magic-link",
+		  .path = "procexe",		.how.resolve = RESOLVE_NO_MAGICLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_magiclinks] normal path to magic-link",
+		  .path = "/proc/self/exe",	.how.resolve = RESOLVE_NO_MAGICLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_magiclinks] normal path to magic-link with O_NOFOLLOW",
+		  .path = "/proc/self/exe",	.how.flags = O_NOFOLLOW,
+						.how.resolve = RESOLVE_NO_MAGICLINKS,
+		  .out.path = procselfexe,	.pass = true },
+		{ .name = "[no_magiclinks] symlink to magic-link path component",
+		  .path = "procroot/etc",	.how.resolve = RESOLVE_NO_MAGICLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_magiclinks] magic-link path component",
+		  .path = "/proc/self/root/etc", .how.resolve = RESOLVE_NO_MAGICLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_magiclinks] magic-link path component with O_NOFOLLOW",
+		  .path = "/proc/self/root/etc", .how.flags = O_NOFOLLOW,
+						 .how.resolve = RESOLVE_NO_MAGICLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+
+		/** RESOLVE_NO_SYMLINKS **/
+		/* Normal paths should work. */
+		{ .name = "[no_symlinks] ordinary path to '.'",
+		  .path = ".",			.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.path = NULL,		.pass = true },
+		{ .name = "[no_symlinks] ordinary path to 'root'",
+		  .path = "root",		.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.path = "root",		.pass = true },
+		{ .name = "[no_symlinks] ordinary path to 'etc'",
+		  .path = "etc",		.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.path = "etc",		.pass = true },
+		{ .name = "[no_symlinks] ordinary path to 'etc/passwd'",
+		  .path = "etc/passwd",		.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.path = "etc/passwd",	.pass = true },
+		/* Regular symlinks are blocked. */
+		{ .name = "[no_symlinks] relative symlink target",
+		  .path = "relsym",		.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_symlinks] relative symlink component",
+		  .path = "reletc/passwd",	.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_symlinks] absolute symlink target",
+		  .path = "abssym",		.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_symlinks] absolute symlink component",
+		  .path = "absetc/passwd",	.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_symlinks] cheeky garbage link",
+		  .path = "cheeky/garbagelink",	.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_symlinks] cheeky absolute + garbage link",
+		  .path = "abscheeky/garbagelink", .how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_symlinks] cheeky absolute + absolute symlink",
+		  .path = "abscheeky/absself",	.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		/* Trailing symlinks with NO_FOLLOW. */
+		{ .name = "[no_symlinks] relative symlink with O_NOFOLLOW",
+		  .path = "relsym",		.how.flags = O_NOFOLLOW,
+						.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.path = "relsym",		.pass = true },
+		{ .name = "[no_symlinks] absolute symlink with O_NOFOLLOW",
+		  .path = "abssym",		.how.flags = O_NOFOLLOW,
+						.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.path = "abssym",		.pass = true },
+		{ .name = "[no_symlinks] trailing symlink with O_NOFOLLOW",
+		  .path = "cheeky/garbagelink",	.how.flags = O_NOFOLLOW,
+						.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.path = "cheeky/garbagelink", .pass = true },
+		{ .name = "[no_symlinks] multiple symlink components with O_NOFOLLOW",
+		  .path = "abscheeky/absself",	.how.flags = O_NOFOLLOW,
+						.how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+		{ .name = "[no_symlinks] multiple symlink (and garbage link) components with O_NOFOLLOW",
+		  .path = "abscheeky/garbagelink", .how.flags = O_NOFOLLOW,
+						   .how.resolve = RESOLVE_NO_SYMLINKS,
+		  .out.err = -ELOOP,		.pass = false },
+	};
+
+	BUILD_BUG_ON(ARRAY_LEN(tests) != NUM_OPENAT2_OPATH_TESTS);
+
+	for (int i = 0; i < ARRAY_LEN(tests); i++) {
+		int dfd, fd;
+		char *fdpath = NULL;
+		bool failed;
+		void (*resultfn)(const char *msg, ...) = ksft_test_result_pass;
+		struct basic_test *test = &tests[i];
+
+		if (!openat2_supported) {
+			ksft_print_msg("openat2(2) unsupported\n");
+			resultfn = ksft_test_result_skip;
+			goto skip;
+		}
+
+		/* Auto-set O_PATH. */
+		if (!(test->how.flags & O_CREAT))
+			test->how.flags |= O_PATH;
+
+		if (test->dir)
+			dfd = openat(rootfd, test->dir, O_PATH | O_DIRECTORY);
+		else
+			dfd = dup(rootfd);
+		E_assert(dfd, "failed to openat root '%s': %m", test->dir);
+
+		E_dup2(dfd, hardcoded_fd);
+
+		fd = sys_openat2(dfd, test->path, &test->how);
+		if (test->pass)
+			failed = (fd < 0 || !fdequal(fd, rootfd, test->out.path));
+		else
+			failed = (fd != test->out.err);
+		if (fd >= 0) {
+			fdpath = fdreadlink(fd);
+			close(fd);
+		}
+		close(dfd);
+
+		if (failed) {
+			resultfn = ksft_test_result_fail;
+
+			ksft_print_msg("openat2 unexpectedly returned ");
+			if (fdpath)
+				ksft_print_msg("%d['%s']\n", fd, fdpath);
+			else
+				ksft_print_msg("%d (%s)\n", fd, strerror(-fd));
+		}
+
+skip:
+		if (test->pass)
+			resultfn("%s gives path '%s'\n", test->name,
+				 test->out.path ?: ".");
+		else
+			resultfn("%s fails with %d (%s)\n", test->name,
+				 test->out.err, strerror(-test->out.err));
+
+		fflush(stdout);
+		free(fdpath);
+	}
+
+	free(procselfexe);
+	close(rootfd);
+
+	free(hardcoded_fdpath);
+	close(hardcoded_fd);
+}
+
+#define NUM_TESTS NUM_OPENAT2_OPATH_TESTS
+
+int main(int argc, char **argv)
+{
+	ksft_print_header();
+	ksft_set_plan(NUM_TESTS);
+
+	/* NOTE: We should be checking for CAP_SYS_ADMIN here... */
+	if (geteuid() != 0)
+		ksft_exit_skip("all tests require euid == 0\n");
+
+	test_openat2_opath_tests();
+
+	if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)
+		ksft_exit_fail();
+	else
+		ksft_exit_pass();
+}