Signed-off-by: Aleksa Sarai cyphar@cyphar.com --- tools/testing/selftests/openat2/Makefile | 2 + tools/testing/selftests/openat2/openat2_test.c | 161 ++++++++++++++++++++++++- 2 files changed, 161 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/openat2/Makefile b/tools/testing/selftests/openat2/Makefile index 185dc76ebb5f..239a7fd0cb35 100644 --- a/tools/testing/selftests/openat2/Makefile +++ b/tools/testing/selftests/openat2/Makefile @@ -12,6 +12,8 @@ ifeq ($(LLVM),) endif
LOCAL_HDRS += helpers.h +# Needed for EEXTSYS_NOOP definition. +CFLAGS += $(TOOLS_INCLUDES)
include ../lib.mk
diff --git a/tools/testing/selftests/openat2/openat2_test.c b/tools/testing/selftests/openat2/openat2_test.c index 4ca175a16ad6..9d3382bdfce9 100644 --- a/tools/testing/selftests/openat2/openat2_test.c +++ b/tools/testing/selftests/openat2/openat2_test.c @@ -1,11 +1,12 @@ // SPDX-License-Identifier: GPL-2.0-or-later /* * Author: Aleksa Sarai cyphar@cyphar.com - * Copyright (C) 2018-2019 SUSE LLC. + * Copyright (C) 2018-2024 SUSE LLC. */
#define _GNU_SOURCE #define __SANE_USERSPACE_TYPES__ // Use ll64 +#include <errno.h> #include <fcntl.h> #include <sched.h> #include <sys/stat.h> @@ -29,6 +30,10 @@ #define O_LARGEFILE 0x8000 #endif
+#ifndef CHECK_FIELDS +#define CHECK_FIELDS (1ULL << 63) +#endif + struct open_how_ext { struct open_how inner; uint32_t extra1; @@ -45,6 +50,152 @@ struct struct_test { int err; };
+static bool check(bool *failed, bool pred) +{ + *failed |= pred; + return pred; +} + +#define NUM_OPENAT2_CHECK_FIELDS_BAD_TESTS 2 + +static void test_openat2_check_fields_bad(const char *name, size_t struct_size) +{ + int fd, expected_err; + bool failed = false; + struct open_how how = {}; + void (*resultfn)(const char *msg, ...) = ksft_test_result_pass; + + if (struct_size < sizeof(struct open_how)) + expected_err = -EINVAL; + if (struct_size > 4096) + expected_err = -E2BIG; + + if (!openat2_supported) { + ksft_print_msg("openat2(2) unsupported\n"); + resultfn = ksft_test_result_skip; + goto skip; + } + + fd = raw_openat2(AT_FDCWD, "", &how, CHECK_FIELDS | struct_size); + if (check(&failed, fd != expected_err)) + ksft_print_msg("openat2(CHECK_FIELDS) returned wrong error code: %d (%s) != %d (%s)\n", + fd, strerror(-fd), + expected_err, strerror(-expected_err)); + + if (fd >= 0) + close(fd); + + if (failed) + resultfn = ksft_test_result_fail; + +skip: + resultfn("openat2(CHECK_FIELDS) with %s returns %d (%s)\n", name, + expected_err, strerror(-expected_err)); + fflush(stdout); +} + +#define NUM_OPENAT2_CHECK_FIELDS_TESTS 1 +#define NUM_OPENAT2_CHECK_FIELDS_VARIATIONS 13 + +static void test_openat2_check_fields(void) +{ + int misalignments[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 17, 87 }; + + for (int i = 0; i < ARRAY_LEN(misalignments); i++) { + int fd, misalign = misalignments[i]; + bool failed = false; + char *fdpath = NULL; + void (*resultfn)(const char *msg, ...) = ksft_test_result_pass; + + struct open_how_ext how_ext = {}, *how_copy = &how_ext; + void *copy = NULL; + + if (!openat2_supported) { + ksft_print_msg("openat2(2) unsupported\n"); + resultfn = ksft_test_result_skip; + goto skip; + } + + if (misalign) { + /* + * Explicitly misalign the structure copying it with + * the given (mis)alignment offset. The other data is + * set to zero and we verify this afterwards to make + * sure CHECK_FIELDS doesn't write outside the buffer. + */ + copy = malloc(misalign*2 + sizeof(how_ext)); + how_copy = copy + misalign; + memset(copy, 0x00, misalign*2 + sizeof(how_ext)); + memcpy(how_copy, &how_ext, sizeof(how_ext)); + } + + fd = raw_openat2(AT_FDCWD, ".", how_copy, CHECK_FIELDS | sizeof(*how_copy)); + if (check(&failed, (fd != -EEXTSYS_NOOP))) + ksft_print_msg("openat2(CHECK_FIELDS) returned wrong error code: %d (%s) != %d\n", + fd, strerror(-fd), -EEXTSYS_NOOP); + if (fd >= 0) { + fdpath = fdreadlink(fd); + close(fd); + } + + if (failed) { + ksft_print_msg("openat2(CHECK_FIELDS) unexpectedly returned "); + if (fdpath) + ksft_print_msg("%d['%s']\n", fd, fdpath); + else + ksft_print_msg("%d (%s)\n", fd, strerror(-fd)); + } + + if (check(&failed, !(how_copy->inner.flags & O_PATH))) + ksft_print_msg("openat2(CHECK_FIELDS) returned flags is missing O_PATH (0x%.16x): 0x%.16llx\n", + O_PATH, how_copy->inner.flags); + + if (check(&failed, (how_copy->inner.mode != 07777))) + ksft_print_msg("openat2(CHECK_FIELDS) returned mode is invalid (0o%o): 0o%.4llo\n", + 07777, how_copy->inner.mode); + + if (check(&failed, !(how_copy->inner.resolve & RESOLVE_IN_ROOT))) + ksft_print_msg("openat2(CHECK_FIELDS) returned resolve flags is missing RESOLVE_IN_ROOT (0x%.16x): 0x%.16llx\n", + RESOLVE_IN_ROOT, how_copy->inner.resolve); + + /* Verify that the buffer space outside the struct wasn't written to. */ + if (check(&failed, how_copy->extra1 != 0)) + ksft_print_msg("openat2(CHECK_FIELDS) touched a byte outside open_how (extra1): 0x%x\n", + how_copy->extra1); + if (check(&failed, how_copy->extra2 != 0)) + ksft_print_msg("openat2(CHECK_FIELDS) touched a byte outside open_how (extra2): 0x%x\n", + how_copy->extra2); + if (check(&failed, how_copy->extra3 != 0)) + ksft_print_msg("openat2(CHECK_FIELDS) touched a byte outside open_how (extra3): 0x%x\n", + how_copy->extra3); + + if (misalign) { + for (size_t i = 0; i < misalign; i++) { + char *p = copy + i; + if (check(&failed, *p != '\x00')) + ksft_print_msg("openat2(CHECK_FIELDS) touched a byte outside the size: buffer[%ld] = 0x%.2x\n", + p - (char *) copy, *p); + } + for (size_t i = 0; i < misalign; i++) { + char *p = copy + misalign + sizeof(how_ext) + i; + if (check(&failed, *p != '\x00')) + ksft_print_msg("openat2(CHECK_FIELDS) touched a byte outside the size: buffer[%ld] = 0x%.2x\n", + p - (char *) copy, *p); + } + } + + if (failed) + resultfn = ksft_test_result_fail; + +skip: + resultfn("openat2(CHECK_FIELDS) [misalign=%d]\n", misalign); + + free(copy); + free(fdpath); + fflush(stdout); + } +} + #define NUM_OPENAT2_STRUCT_TESTS 7 #define NUM_OPENAT2_STRUCT_VARIATIONS 13
@@ -320,7 +471,9 @@ void test_openat2_flags(void) } }
-#define NUM_TESTS (NUM_OPENAT2_STRUCT_VARIATIONS * NUM_OPENAT2_STRUCT_TESTS + \ +#define NUM_TESTS (NUM_OPENAT2_CHECK_FIELDS_TESTS * NUM_OPENAT2_CHECK_FIELDS_VARIATIONS + \ + NUM_OPENAT2_CHECK_FIELDS_BAD_TESTS + \ + NUM_OPENAT2_STRUCT_VARIATIONS * NUM_OPENAT2_STRUCT_TESTS + \ NUM_OPENAT2_FLAG_TESTS)
int main(int argc, char **argv) @@ -328,6 +481,10 @@ int main(int argc, char **argv) ksft_print_header(); ksft_set_plan(NUM_TESTS);
+ test_openat2_check_fields(); + test_openat2_check_fields_bad("small struct (< v0)", 0); + test_openat2_check_fields_bad("large struct (> PAGE_SIZE)", 0xF000); + test_openat2_struct(); test_openat2_flags();