diff options
Diffstat (limited to 'tools/testing/selftests/filesystems/openat2')
7 files changed, 1313 insertions, 0 deletions
diff --git a/tools/testing/selftests/filesystems/openat2/.gitignore b/tools/testing/selftests/filesystems/openat2/.gitignore new file mode 100644 index 000000000000..82a4846cbc4b --- /dev/null +++ b/tools/testing/selftests/filesystems/openat2/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +/*_test diff --git a/tools/testing/selftests/filesystems/openat2/Makefile b/tools/testing/selftests/filesystems/openat2/Makefile new file mode 100644 index 000000000000..d848aac96bde --- /dev/null +++ b/tools/testing/selftests/filesystems/openat2/Makefile @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +CFLAGS += $(KHDR_INCLUDES) +CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined $(TOOLS_INCLUDES) +TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test emptypath_test + +# gcc requires -static-libasan in order to ensure that Address Sanitizer's +# library is the first one loaded. However, clang already statically links the +# Address Sanitizer if -fsanitize is specified. Therefore, simply omit +# -static-libasan for clang builds. +ifeq ($(LLVM),) + CFLAGS += -static-libasan +endif + +LOCAL_HDRS += helpers.h + +include ../../lib.mk diff --git a/tools/testing/selftests/filesystems/openat2/emptypath_test.c b/tools/testing/selftests/filesystems/openat2/emptypath_test.c new file mode 100644 index 000000000000..be37ccba57ec --- /dev/null +++ b/tools/testing/selftests/filesystems/openat2/emptypath_test.c @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#define _GNU_SOURCE +#define __SANE_USERSPACE_TYPES__ +#include <fcntl.h> +#include <unistd.h> +#include <errno.h> +#include <string.h> +#include <sys/stat.h> + +#include "kselftest_harness.h" + +#ifndef O_EMPTYPATH +#define O_EMPTYPATH (1 << 26) +#endif + +#define EMPTYPATH_TEST_FILE "/tmp/emptypath_test" + +FIXTURE(emptypath) { + int opath_fd; +}; + +FIXTURE_SETUP(emptypath) +{ + int fd; + + self->opath_fd = -1; + + fd = open(EMPTYPATH_TEST_FILE, O_CREAT | O_WRONLY, S_IRWXU); + ASSERT_GE(fd, 0) { + TH_LOG("create %s: %s", EMPTYPATH_TEST_FILE, strerror(errno)); + } + close(fd); + + self->opath_fd = open(EMPTYPATH_TEST_FILE, O_PATH); + ASSERT_GE(self->opath_fd, 0) { + TH_LOG("open %s O_PATH: %s", EMPTYPATH_TEST_FILE, strerror(errno)); + } +} + +FIXTURE_TEARDOWN(emptypath) +{ + if (self->opath_fd >= 0) + close(self->opath_fd); + unlink(EMPTYPATH_TEST_FILE); +} + +/* An empty path is rejected with ENOENT unless O_EMPTYPATH is set. */ +TEST_F(emptypath, without_flag_returns_enoent) +{ + int fd = openat(self->opath_fd, "", O_RDONLY); + + if (fd >= 0) + close(fd); + ASSERT_LT(fd, 0) { + TH_LOG("empty path without O_EMPTYPATH unexpectedly succeeded"); + } + EXPECT_EQ(errno, ENOENT) { + TH_LOG("expected ENOENT, got %s", strerror(errno)); + } +} + +/* O_EMPTYPATH reopens the O_PATH fd through an empty path. */ +TEST_F(emptypath, reopens_opath_fd) +{ + int fd = openat(self->opath_fd, "", O_RDONLY | O_EMPTYPATH); + + if (fd < 0 && errno == EINVAL) + SKIP(return, "O_EMPTYPATH not supported"); + + ASSERT_GE(fd, 0) { + TH_LOG("O_EMPTYPATH failed: %s", strerror(errno)); + } + close(fd); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/filesystems/openat2/helpers.h b/tools/testing/selftests/filesystems/openat2/helpers.h new file mode 100644 index 000000000000..3f01fb68c5a6 --- /dev/null +++ b/tools/testing/selftests/filesystems/openat2/helpers.h @@ -0,0 +1,135 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Author: Aleksa Sarai <cyphar@cyphar.com> + * Copyright (C) 2018-2019 SUSE LLC. + * Copyright (C) 2026 Amutable GmbH + */ + +#ifndef __RESOLVEAT_H__ +#define __RESOLVEAT_H__ + +#define _GNU_SOURCE +#include <stdint.h> +#include <stdbool.h> +#include <errno.h> +#include <limits.h> +#include <linux/types.h> +#include <linux/unistd.h> +#include <linux/openat2.h> +#include "kselftest_harness.h" + +#define BUILD_BUG_ON(e) ((void)(sizeof(struct { int:(-!!(e)); }))) + +#define OPEN_HOW_SIZE_VER0 24 /* sizeof first published struct */ +#define OPEN_HOW_SIZE_LATEST OPEN_HOW_SIZE_VER0 + +__maybe_unused +static bool needs_openat2(const struct open_how *how) +{ + return how->resolve != 0; +} + +__maybe_unused +static int raw_openat2(int dfd, const char *path, void *how, size_t size) +{ + int ret = syscall(__NR_openat2, dfd, path, how, size); + + return ret >= 0 ? ret : -errno; +} + +__maybe_unused +static int sys_openat2(int dfd, const char *path, struct open_how *how) +{ + return raw_openat2(dfd, path, how, sizeof(*how)); +} + +__maybe_unused +static int sys_openat(int dfd, const char *path, struct open_how *how) +{ + int ret = openat(dfd, path, how->flags, how->mode); + + return ret >= 0 ? ret : -errno; +} + +__maybe_unused +static int sys_renameat2(int olddirfd, const char *oldpath, + int newdirfd, const char *newpath, unsigned int flags) +{ + int ret = syscall(__NR_renameat2, olddirfd, oldpath, + newdirfd, newpath, flags); + + return ret >= 0 ? ret : -errno; +} + +__maybe_unused +static int touchat(int dfd, const char *path) +{ + int fd = openat(dfd, path, O_CREAT, 0700); + + if (fd >= 0) + close(fd); + return fd; +} + +__maybe_unused +static char *fdreadlink(struct __test_metadata *_metadata, int fd) +{ + char *target, *tmp; + + ASSERT_GT(asprintf(&tmp, "/proc/self/fd/%d", fd), 0); + + target = malloc(PATH_MAX); + ASSERT_NE(target, NULL); + memset(target, 0, PATH_MAX); + + ASSERT_GT(readlink(tmp, target, PATH_MAX), 0); + + free(tmp); + return target; +} + +__maybe_unused +static bool fdequal(struct __test_metadata *_metadata, int fd, + int dfd, const char *path) +{ + char *fdpath, *dfdpath, *other; + bool cmp; + + fdpath = fdreadlink(_metadata, fd); + dfdpath = fdreadlink(_metadata, dfd); + + if (!path) { + ASSERT_GT(asprintf(&other, "%s", dfdpath), 0); + } else if (*path == '/') { + ASSERT_GT(asprintf(&other, "%s", path), 0); + } else { + ASSERT_GT(asprintf(&other, "%s/%s", dfdpath, path), 0); + } + + cmp = !strcmp(fdpath, other); + + free(fdpath); + free(dfdpath); + free(other); + return cmp; +} + +static bool openat2_supported = false; + +__attribute__((constructor)) +static void __detect_openat2_supported(void) +{ + struct open_how how = {}; + int fd; + + BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_VER0); + + /* Check openat2(2) support. */ + fd = sys_openat2(AT_FDCWD, ".", &how); + openat2_supported = (fd >= 0); + + if (fd >= 0) + close(fd); +} + +#endif /* __RESOLVEAT_H__ */ diff --git a/tools/testing/selftests/filesystems/openat2/openat2_test.c b/tools/testing/selftests/filesystems/openat2/openat2_test.c new file mode 100644 index 000000000000..6f5afbe2d8d3 --- /dev/null +++ b/tools/testing/selftests/filesystems/openat2/openat2_test.c @@ -0,0 +1,362 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Author: Aleksa Sarai <cyphar@cyphar.com> + * Copyright (C) 2018-2019 SUSE LLC. + */ + +#define _GNU_SOURCE +#define __SANE_USERSPACE_TYPES__ // Use ll64 +#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 "helpers.h" +#include "kselftest_harness.h" + +/* + * O_LARGEFILE is set to 0 by glibc. + * XXX: This is wrong on {mips, parisc, powerpc, sparc}. + */ +#undef O_LARGEFILE +#ifdef __aarch64__ +#define O_LARGEFILE 0x20000 +#else +#define O_LARGEFILE 0x8000 +#endif + +struct open_how_ext { + struct open_how inner; + uint32_t extra1; + char pad1[128]; + uint32_t extra2; + char pad2[128]; + uint32_t extra3; +}; + +struct struct_test { + const char *name; + struct open_how_ext arg; + size_t size; + int err; +}; + +struct flag_test { + const char *name; + struct open_how how; + int err; +}; + +FIXTURE(openat2) {}; + +FIXTURE_SETUP(openat2) +{ + if (!openat2_supported) + SKIP(return, "openat2(2) not supported"); +} + +FIXTURE_TEARDOWN(openat2) {} + +/* + * Verify that the struct size and misalignment handling for openat2(2) is + * correct, including that is_zeroed_user() works. + */ +TEST_F(openat2, struct_argument_sizes) +{ + int misalignments[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 17, 87 }; + struct struct_test tests[] = { + /* Normal struct. */ + { .name = "normal struct", + .arg.inner.flags = O_RDONLY, + .size = sizeof(struct open_how) }, + /* Bigger struct, with zeroed out end. */ + { .name = "bigger struct (zeroed out)", + .arg.inner.flags = O_RDONLY, + .size = sizeof(struct open_how_ext) }, + + /* TODO: Once expanded, check zero-padding. */ + + /* Smaller than version-0 struct. */ + { .name = "zero-sized 'struct'", + .arg.inner.flags = O_RDONLY, .size = 0, .err = -EINVAL }, + { .name = "smaller-than-v0 struct", + .arg.inner.flags = O_RDONLY, + .size = OPEN_HOW_SIZE_VER0 - 1, .err = -EINVAL }, + + /* Bigger struct, with non-zero trailing bytes. */ + { .name = "bigger struct (non-zero data in first 'future field')", + .arg.inner.flags = O_RDONLY, .arg.extra1 = 0xdeadbeef, + .size = sizeof(struct open_how_ext), .err = -E2BIG }, + { .name = "bigger struct (non-zero data in middle of 'future fields')", + .arg.inner.flags = O_RDONLY, .arg.extra2 = 0xfeedcafe, + .size = sizeof(struct open_how_ext), .err = -E2BIG }, + { .name = "bigger struct (non-zero data at end of 'future fields')", + .arg.inner.flags = O_RDONLY, .arg.extra3 = 0xabad1dea, + .size = sizeof(struct open_how_ext), .err = -E2BIG }, + }; + + for (int i = 0; i < ARRAY_SIZE(tests); i++) { + struct struct_test *test = &tests[i]; + struct open_how_ext how_ext = test->arg; + + for (int j = 0; j < ARRAY_SIZE(misalignments); j++) { + int fd, misalign = misalignments[j]; + void *copy = NULL, *how_copy = &how_ext; + char *fdpath = NULL; + + if (misalign) { + /* + * Explicitly misalign the structure copying it with the given + * (mis)alignment offset. The other data is set to be non-zero to + * make sure that non-zero bytes outside the struct aren't checked + * + * This is effectively to check that is_zeroed_user() works. + */ + copy = malloc(misalign + sizeof(how_ext)); + how_copy = copy + misalign; + memset(copy, 0xff, misalign); + memcpy(how_copy, &how_ext, sizeof(how_ext)); + } + + fd = raw_openat2(AT_FDCWD, ".", how_copy, test->size); + if (fd >= 0) { + fdpath = fdreadlink(_metadata, fd); + close(fd); + } + + if (test->err >= 0) { + EXPECT_GE(fd, 0) { + TH_LOG("openat2 with %s [misalign=%d] should succeed, got %d (%s)", + test->name, misalign, + fd, strerror(-fd)); + } + } else { + EXPECT_EQ(test->err, fd) { + if (fdpath) + TH_LOG("openat2 with %s [misalign=%d] should fail with %d (%s), got %d['%s']", + test->name, misalign, + test->err, + strerror(-test->err), + fd, fdpath); + else + TH_LOG("openat2 with %s [misalign=%d] should fail with %d (%s), got %d (%s)", + test->name, misalign, + test->err, + strerror(-test->err), + fd, strerror(-fd)); + } + } + + free(copy); + free(fdpath); + } + } +} + +/* Verify openat2(2) flag and mode validation. */ +TEST_F(openat2, flag_validation) +{ + struct flag_test tests[] = { + /* O_TMPFILE is incompatible with O_PATH and O_CREAT. */ + { .name = "incompatible flags (O_TMPFILE | O_PATH)", + .how.flags = O_TMPFILE | O_PATH | O_RDWR, .err = -EINVAL }, + { .name = "incompatible flags (O_TMPFILE | O_CREAT)", + .how.flags = O_TMPFILE | O_CREAT | O_RDWR, .err = -EINVAL }, + + /* O_PATH only permits certain other flags to be set ... */ + { .name = "compatible flags (O_PATH | O_CLOEXEC)", + .how.flags = O_PATH | O_CLOEXEC }, + { .name = "compatible flags (O_PATH | O_DIRECTORY)", + .how.flags = O_PATH | O_DIRECTORY }, + { .name = "compatible flags (O_PATH | O_NOFOLLOW)", + .how.flags = O_PATH | O_NOFOLLOW }, + /* ... and others are absolutely not permitted. */ + { .name = "incompatible flags (O_PATH | O_RDWR)", + .how.flags = O_PATH | O_RDWR, .err = -EINVAL }, + { .name = "incompatible flags (O_PATH | O_CREAT)", + .how.flags = O_PATH | O_CREAT, .err = -EINVAL }, + { .name = "incompatible flags (O_PATH | O_EXCL)", + .how.flags = O_PATH | O_EXCL, .err = -EINVAL }, + { .name = "incompatible flags (O_PATH | O_NOCTTY)", + .how.flags = O_PATH | O_NOCTTY, .err = -EINVAL }, + { .name = "incompatible flags (O_PATH | O_DIRECT)", + .how.flags = O_PATH | O_DIRECT, .err = -EINVAL }, + { .name = "incompatible flags (O_PATH | O_LARGEFILE)", + .how.flags = O_PATH | O_LARGEFILE, .err = -EINVAL }, + + /* ->mode must only be set with O_{CREAT,TMPFILE}. */ + { .name = "non-zero how.mode and O_RDONLY", + .how.flags = O_RDONLY, .how.mode = 0600, .err = -EINVAL }, + { .name = "non-zero how.mode and O_PATH", + .how.flags = O_PATH, .how.mode = 0600, .err = -EINVAL }, + { .name = "valid how.mode and O_CREAT", + .how.flags = O_CREAT, .how.mode = 0600 }, + { .name = "valid how.mode and O_TMPFILE", + .how.flags = O_TMPFILE | O_RDWR, .how.mode = 0600 }, + /* ->mode must only contain 0777 bits. */ + { .name = "invalid how.mode and O_CREAT", + .how.flags = O_CREAT, + .how.mode = 0xFFFF, .err = -EINVAL }, + { .name = "invalid (very large) how.mode and O_CREAT", + .how.flags = O_CREAT, + .how.mode = 0xC000000000000000ULL, .err = -EINVAL }, + { .name = "invalid how.mode and O_TMPFILE", + .how.flags = O_TMPFILE | O_RDWR, + .how.mode = 0x1337, .err = -EINVAL }, + { .name = "invalid (very large) how.mode and O_TMPFILE", + .how.flags = O_TMPFILE | O_RDWR, + .how.mode = 0x0000A00000000000ULL, .err = -EINVAL }, + + /* ->resolve flags must not conflict. */ + { .name = "incompatible resolve flags (BENEATH | IN_ROOT)", + .how.flags = O_RDONLY, + .how.resolve = RESOLVE_BENEATH | RESOLVE_IN_ROOT, + .err = -EINVAL }, + + /* ->resolve must only contain RESOLVE_* flags. */ + { .name = "invalid how.resolve and O_RDONLY", + .how.flags = O_RDONLY, + .how.resolve = 0x1337, .err = -EINVAL }, + { .name = "invalid how.resolve and O_CREAT", + .how.flags = O_CREAT, + .how.resolve = 0x1337, .err = -EINVAL }, + { .name = "invalid how.resolve and O_TMPFILE", + .how.flags = O_TMPFILE | O_RDWR, + .how.resolve = 0x1337, .err = -EINVAL }, + { .name = "invalid how.resolve and O_PATH", + .how.flags = O_PATH, + .how.resolve = 0x1337, .err = -EINVAL }, + + /* currently unknown upper 32 bit rejected. */ + { .name = "currently unknown bit (1 << 63)", + .how.flags = O_RDONLY | (1ULL << 63), + .how.resolve = 0, .err = -EINVAL }, + }; + + for (int i = 0; i < ARRAY_SIZE(tests); i++) { + int fd, fdflags = -1; + char *path, *fdpath = NULL; + struct flag_test *test = &tests[i]; + + path = (test->how.flags & O_CREAT) ? "/tmp/ksft.openat2_tmpfile" : "."; + unlink(path); + + fd = sys_openat2(AT_FDCWD, path, &test->how); + if (fd < 0 && fd == -EOPNOTSUPP) { + /* + * Skip the testcase if it failed because not supported + * by FS. (e.g. a valid O_TMPFILE combination on NFS) + */ + TH_LOG("openat2 with %s not supported by FS -- skipping", + test->name); + continue; + } + + if (test->err >= 0) { + EXPECT_GE(fd, 0) { + TH_LOG("openat2 with %s should succeed, got %d (%s)", + test->name, fd, strerror(-fd)); + } + if (fd >= 0) { + int otherflags; + + fdpath = fdreadlink(_metadata, fd); + fdflags = fcntl(fd, F_GETFL); + otherflags = fcntl(fd, F_GETFD); + close(fd); + + ASSERT_GE(fdflags, 0); + ASSERT_GE(otherflags, 0); + + /* O_CLOEXEC isn't shown in F_GETFL. */ + if (otherflags & FD_CLOEXEC) + fdflags |= O_CLOEXEC; + /* O_CREAT is hidden from F_GETFL. */ + if (test->how.flags & O_CREAT) + fdflags |= O_CREAT; + if (!(test->how.flags & O_LARGEFILE)) + fdflags &= ~O_LARGEFILE; + + EXPECT_EQ(fdflags, (int)test->how.flags) { + TH_LOG("openat2 with %s: flags mismatch %X != %llX", + test->name, fdflags, + (unsigned long long)test->how.flags); + } + } + } else { + EXPECT_EQ(test->err, fd) { + if (fd >= 0) { + fdpath = fdreadlink(_metadata, fd); + TH_LOG("openat2 with %s should fail with %d (%s), got %d['%s']", + test->name, test->err, + strerror(-test->err), + fd, fdpath); + } else { + TH_LOG("openat2 with %s should fail with %d (%s), got %d (%s)", + test->name, test->err, + strerror(-test->err), + fd, strerror(-fd)); + } + } + if (fd >= 0) + close(fd); + } + + free(fdpath); + } +} + +#ifndef OPENAT2_REGULAR +#define OPENAT2_REGULAR ((__u64)1 << 32) +#endif + +#ifndef EFTYPE +#define EFTYPE 134 +#endif + +/* Kernel-internal carrier for OPENAT2_REGULAR (see __O_REGULAR in fcntl.h). */ +#ifndef __O_REGULAR +#define __O_REGULAR (1 << 30) +#endif + +/* Verify that OPENAT2_REGULAR rejects non-regular files with EFTYPE. */ +TEST_F(openat2, regular_flag) +{ + struct open_how how = { + .flags = OPENAT2_REGULAR | O_RDONLY, + }; + int fd; + + fd = sys_openat2(AT_FDCWD, "/dev/null", &how); + if (fd == -ENOENT) + SKIP(return, "/dev/null does not exist"); + + EXPECT_EQ(-EFTYPE, fd) { + TH_LOG("openat2 with OPENAT2_REGULAR should fail with %d (%s), got %d (%s)", + -EFTYPE, strerror(EFTYPE), fd, strerror(-fd)); + } + if (fd >= 0) + close(fd); +} + +/* open()/openat() must keep ignoring the internal __O_REGULAR bit. */ +TEST(legacy_openat_ignores_o_regular) +{ + int fd; + + fd = openat(AT_FDCWD, "/dev/null", O_RDONLY | __O_REGULAR); + if (fd < 0 && errno == ENOENT) + SKIP(return, "/dev/null does not exist"); + + ASSERT_GE(fd, 0) { + TH_LOG("legacy openat() must ignore the __O_REGULAR carrier bit, got errno %d (%s)", + errno, strerror(errno)); + } + close(fd); +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/filesystems/openat2/rename_attack_test.c b/tools/testing/selftests/filesystems/openat2/rename_attack_test.c new file mode 100644 index 000000000000..1f33c34f56be --- /dev/null +++ b/tools/testing/selftests/filesystems/openat2/rename_attack_test.c @@ -0,0 +1,159 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Author: Aleksa Sarai <cyphar@cyphar.com> + * Copyright (C) 2018-2019 SUSE LLC. + */ + +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <sched.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/mount.h> +#include <sys/mman.h> +#include <sys/prctl.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdbool.h> +#include <string.h> +#include <syscall.h> +#include <limits.h> +#include <unistd.h> + +#include "helpers.h" +#include "kselftest_harness.h" + +#define ROUNDS 400000 + +/* Swap @dirfd/@a and @dirfd/@b constantly. Parent must kill this process. */ +pid_t spawn_attack(struct __test_metadata *_metadata, + int dirfd, char *a, char *b) +{ + pid_t child = fork(); + if (child != 0) + return child; + + /* If the parent (the test process) dies, kill ourselves too. */ + ASSERT_EQ(prctl(PR_SET_PDEATHSIG, SIGKILL), 0); + + /* Swap @a and @b. */ + for (;;) + renameat2(dirfd, a, dirfd, b, RENAME_EXCHANGE); + exit(1); +} + +/* + * Construct a test directory with the following structure: + * + * root/ + * |-- a/ + * | `-- c/ + * `-- b/ + */ +FIXTURE(rename_attack) { + int dfd; + int afd; + pid_t child; +}; + +FIXTURE_SETUP(rename_attack) +{ + char dirname[] = "/tmp/ksft-openat2-rename-attack.XXXXXX"; + + self->dfd = -1; + self->afd = -1; + self->child = 0; + + /* Make the top-level directory. */ + ASSERT_NE(mkdtemp(dirname), NULL); + self->dfd = open(dirname, O_PATH | O_DIRECTORY); + ASSERT_GE(self->dfd, 0); + + ASSERT_EQ(mkdirat(self->dfd, "a", 0755), 0); + ASSERT_EQ(mkdirat(self->dfd, "b", 0755), 0); + ASSERT_EQ(mkdirat(self->dfd, "a/c", 0755), 0); + + self->afd = openat(self->dfd, "a", O_PATH); + ASSERT_GE(self->afd, 0); + + self->child = spawn_attack(_metadata, self->dfd, "a/c", "b"); + ASSERT_GT(self->child, 0); +} + +FIXTURE_TEARDOWN(rename_attack) +{ + if (self->child > 0) + kill(self->child, SIGKILL); + if (self->afd >= 0) + close(self->afd); + if (self->dfd >= 0) + close(self->dfd); +} + +FIXTURE_VARIANT(rename_attack) { + int resolve; + const char *name; +}; + +FIXTURE_VARIANT_ADD(rename_attack, resolve_beneath) { + .resolve = RESOLVE_BENEATH, + .name = "RESOLVE_BENEATH", +}; + +FIXTURE_VARIANT_ADD(rename_attack, resolve_in_root) { + .resolve = RESOLVE_IN_ROOT, + .name = "RESOLVE_IN_ROOT", +}; + +TEST_F_TIMEOUT(rename_attack, test, 120) +{ + int escapes = 0, successes = 0, other_errs = 0, exdevs = 0, eagains = 0; + char *victim_path = "c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../../c/../.."; + struct open_how how = { + .flags = O_PATH, + .resolve = variant->resolve, + }; + + if (!openat2_supported) { + how.resolve = 0; + TH_LOG("openat2(2) unsupported -- using openat(2) instead"); + } + + for (int i = 0; i < ROUNDS; i++) { + int fd; + + if (openat2_supported) + fd = sys_openat2(self->afd, victim_path, &how); + else + fd = sys_openat(self->afd, victim_path, &how); + + if (fd < 0) { + if (fd == -EAGAIN) + eagains++; + else if (fd == -EXDEV) + exdevs++; + else if (fd == -ENOENT) + escapes++; /* escaped outside and got ENOENT... */ + else + other_errs++; /* unexpected error */ + } else { + if (fdequal(_metadata, fd, self->afd, NULL)) + successes++; + else + escapes++; /* we got an unexpected fd */ + } + if (fd >= 0) + close(fd); + } + + TH_LOG("non-escapes: EAGAIN=%d EXDEV=%d E<other>=%d success=%d", + eagains, exdevs, other_errs, successes); + ASSERT_EQ(escapes, 0) { + TH_LOG("rename attack with %s (%d runs, got %d escapes)", + variant->name, ROUNDS, escapes); + } +} + +TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/filesystems/openat2/resolve_test.c b/tools/testing/selftests/filesystems/openat2/resolve_test.c new file mode 100644 index 000000000000..eacde59ce158 --- /dev/null +++ b/tools/testing/selftests/filesystems/openat2/resolve_test.c @@ -0,0 +1,561 @@ +// 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 "helpers.h" +#include "kselftest_harness.h" + +struct resolve_test { + const char *name; + const char *dir; + const char *path; + struct open_how how; + bool pass; + union { + int err; + const char *path; + } out; +}; + +/* + * Verify a single resolve test case. This must be called from within a TEST_F + * function with _metadata in scope. + */ +static void verify_resolve_test(struct __test_metadata *_metadata, + int rootfd, int hardcoded_fd, + const struct resolve_test *test) +{ + struct open_how how = test->how; + int dfd, fd; + char *fdpath = NULL; + + /* Auto-set O_PATH. */ + if (!(how.flags & O_CREAT)) + how.flags |= O_PATH; + + if (test->dir) + dfd = openat(rootfd, test->dir, O_PATH | O_DIRECTORY); + else + dfd = dup(rootfd); + ASSERT_GE(dfd, 0) TH_LOG("failed to open dir '%s': %m", test->dir ?: "."); + ASSERT_EQ(dup2(dfd, hardcoded_fd), hardcoded_fd); + + fd = sys_openat2(dfd, test->path, &how); + + if (test->pass) { + EXPECT_GE(fd, 0) { + TH_LOG("%s: expected success, got %d (%s)", + test->name, fd, strerror(-fd)); + } + if (fd >= 0) { + EXPECT_TRUE(fdequal(_metadata, fd, rootfd, test->out.path)) { + fdpath = fdreadlink(_metadata, fd); + TH_LOG("%s: wrong path '%s', expected '%s'", + test->name, fdpath, + test->out.path ?: "."); + free(fdpath); + } + } + } else { + EXPECT_EQ(test->out.err, fd) { + if (fd >= 0) { + fdpath = fdreadlink(_metadata, fd); + TH_LOG("%s: expected %d (%s), got %d['%s']", + test->name, test->out.err, + strerror(-test->out.err), fd, fdpath); + free(fdpath); + } else { + TH_LOG("%s: expected %d (%s), got %d (%s)", + test->name, test->out.err, + strerror(-test->out.err), + fd, strerror(-fd)); + } + } + } + + if (fd >= 0) + close(fd); + close(dfd); +} + +/* + * 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/../etc/../etc/passwd + * |-- abspasswd -> /../cheeky/../etc/../etc/passwd + * |-- dotdotlink -> ../../../../../../../../../../../../../../etc/passwd + * `-- garbagelink -> /../../../../../../../../../../../../../../etc/passwd + */ +FIXTURE(openat2_resolve) { + int rootfd; + int hardcoded_fd; + char *hardcoded_fdpath; + char *procselfexe; +}; + +FIXTURE_SETUP(openat2_resolve) +{ + char dirname[] = "/tmp/ksft-openat2-testdir.XXXXXX"; + int dfd, tmpfd; + + self->rootfd = -1; + self->hardcoded_fd = -1; + self->hardcoded_fdpath = NULL; + self->procselfexe = NULL; + + /* NOTE: We should be checking for CAP_SYS_ADMIN here... */ + if (geteuid() != 0) + SKIP(return, "all tests require euid == 0"); + if (!openat2_supported) + SKIP(return, "openat2(2) not supported"); + + /* Unshare and make /tmp a new directory. */ + ASSERT_EQ(unshare(CLONE_NEWNS), 0); + ASSERT_EQ(mount("", "/tmp", "", MS_PRIVATE, ""), 0); + + /* Make the top-level directory. */ + ASSERT_NE(mkdtemp(dirname), NULL); + dfd = open(dirname, O_PATH | O_DIRECTORY); + ASSERT_GE(dfd, 0); + + /* A sub-directory which is actually used for tests. */ + ASSERT_EQ(mkdirat(dfd, "root", 0755), 0); + tmpfd = openat(dfd, "root", O_PATH | O_DIRECTORY); + ASSERT_GE(tmpfd, 0); + close(dfd); + dfd = tmpfd; + + ASSERT_EQ(symlinkat("/proc/self/exe", dfd, "procexe"), 0); + ASSERT_EQ(symlinkat("/proc/self/root", dfd, "procroot"), 0); + ASSERT_EQ(mkdirat(dfd, "root", 0755), 0); + + /* There is no mountat(2), so use chdir. */ + ASSERT_EQ(mkdirat(dfd, "mnt", 0755), 0); + ASSERT_EQ(fchdir(dfd), 0); + ASSERT_EQ(mount("tmpfs", "./mnt", "tmpfs", MS_NOSUID | MS_NODEV, ""), 0); + ASSERT_EQ(symlinkat("../mnt/", dfd, "mnt/self"), 0); + ASSERT_EQ(symlinkat("/mnt/", dfd, "mnt/absself"), 0); + + ASSERT_EQ(mkdirat(dfd, "etc", 0755), 0); + ASSERT_GE(touchat(dfd, "etc/passwd"), 0); + + ASSERT_EQ(symlinkat("/newfile3", dfd, "creatlink"), 0); + ASSERT_EQ(symlinkat("etc/", dfd, "reletc"), 0); + ASSERT_EQ(symlinkat("etc/passwd", dfd, "relsym"), 0); + ASSERT_EQ(symlinkat("/etc/", dfd, "absetc"), 0); + ASSERT_EQ(symlinkat("/etc/passwd", dfd, "abssym"), 0); + ASSERT_EQ(symlinkat("/cheeky", dfd, "abscheeky"), 0); + + ASSERT_EQ(mkdirat(dfd, "cheeky", 0755), 0); + + ASSERT_EQ(symlinkat("/", dfd, "cheeky/absself"), 0); + ASSERT_EQ(symlinkat("../../root/", dfd, "cheeky/self"), 0); + ASSERT_EQ(symlinkat("/../../root/", dfd, "cheeky/garbageself"), 0); + + ASSERT_EQ(symlinkat("../cheeky/../etc/../etc/passwd", + dfd, "cheeky/passwd"), 0); + ASSERT_EQ(symlinkat("/../cheeky/../etc/../etc/passwd", + dfd, "cheeky/abspasswd"), 0); + + ASSERT_EQ(symlinkat("../../../../../../../../../../../../../../etc/passwd", + dfd, "cheeky/dotdotlink"), 0); + ASSERT_EQ(symlinkat("/../../../../../../../../../../../../../../etc/passwd", + dfd, "cheeky/garbagelink"), 0); + + self->rootfd = dfd; + + self->hardcoded_fd = open("/dev/null", O_RDONLY); + ASSERT_GE(self->hardcoded_fd, 0); + ASSERT_GE(asprintf(&self->hardcoded_fdpath, "self/fd/%d", + self->hardcoded_fd), 0); + ASSERT_GE(asprintf(&self->procselfexe, "/proc/%d/exe", getpid()), 0); +} + +FIXTURE_TEARDOWN(openat2_resolve) +{ + free(self->procselfexe); + free(self->hardcoded_fdpath); + if (self->hardcoded_fd >= 0) + close(self->hardcoded_fd); + if (self->rootfd >= 0) + close(self->rootfd); +} + +/* Attempts to cross the dirfd should be blocked with -EXDEV. */ +TEST_F(openat2_resolve, resolve_beneath) +{ + struct resolve_test tests[] = { + /* 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 }, + }; + + for (int i = 0; i < ARRAY_SIZE(tests); i++) + verify_resolve_test(_metadata, self->rootfd, + self->hardcoded_fd, &tests[i]); +} + +/* All attempts to cross the dirfd will be scoped-to-root. */ +TEST_F(openat2_resolve, resolve_in_root) +{ + struct resolve_test tests[] = { + { .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 }, + }; + + for (int i = 0; i < ARRAY_SIZE(tests); i++) + verify_resolve_test(_metadata, self->rootfd, + self->hardcoded_fd, &tests[i]); +} + +/* Crossing mount boundaries should be blocked. */ +TEST_F(openat2_resolve, resolve_no_xdev) +{ + struct resolve_test tests[] = { + /* 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 = self->hardcoded_fdpath, .how.resolve = RESOLVE_NO_XDEV, + .out.path = "/proc", .pass = true, }, + }; + + for (int i = 0; i < ARRAY_SIZE(tests); i++) + verify_resolve_test(_metadata, self->rootfd, + self->hardcoded_fd, &tests[i]); +} + +/* Procfs-style magic-link resolution should be blocked. */ +TEST_F(openat2_resolve, resolve_no_magiclinks) +{ + struct resolve_test tests[] = { + /* 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 = self->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 }, + }; + + for (int i = 0; i < ARRAY_SIZE(tests); i++) + verify_resolve_test(_metadata, self->rootfd, + self->hardcoded_fd, &tests[i]); +} + +/* All symlink resolution should be blocked. */ +TEST_F(openat2_resolve, resolve_no_symlinks) +{ + struct resolve_test tests[] = { + /* 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 }, + }; + + for (int i = 0; i < ARRAY_SIZE(tests); i++) + verify_resolve_test(_metadata, self->rootfd, + self->hardcoded_fd, &tests[i]); +} + +TEST_HARNESS_MAIN |