diff options
Diffstat (limited to 'tools/testing/selftests/seccomp/seccomp_bpf.c')
| -rw-r--r-- | tools/testing/selftests/seccomp/seccomp_bpf.c | 382 |
1 files changed, 367 insertions, 15 deletions
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 38f651469968..14ba51b52095 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -47,6 +47,7 @@ #include <linux/kcmp.h> #include <sys/resource.h> #include <sys/capability.h> +#include <linux/perf_event.h> #include <unistd.h> #include <sys/syscall.h> @@ -60,12 +61,18 @@ #define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__) #endif +#ifndef MIN #define MIN(X, Y) ((X) < (Y) ? (X) : (Y)) +#endif #ifndef PR_SET_PTRACER # define PR_SET_PTRACER 0x59616d61 #endif +#ifndef noinline +#define noinline __attribute__((noinline)) +#endif + #ifndef PR_SET_NO_NEW_PRIVS #define PR_SET_NO_NEW_PRIVS 38 #define PR_GET_NO_NEW_PRIVS 39 @@ -784,7 +791,7 @@ void *kill_thread(void *data) bool die = (bool)data; if (die) { - prctl(PR_GET_SECCOMP, 0, 0, 0, 0); + syscall(__NR_getpid); return (void *)SIBLING_EXIT_FAILURE; } @@ -803,11 +810,11 @@ void kill_thread_or_group(struct __test_metadata *_metadata, { pthread_t thread; void *status; - /* Kill only when calling __NR_prctl. */ + /* Kill only when calling __NR_getpid. */ struct sock_filter filter_thread[] = { BPF_STMT(BPF_LD|BPF_W|BPF_ABS, offsetof(struct seccomp_data, nr)), - BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL_THREAD), BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), }; @@ -819,7 +826,7 @@ void kill_thread_or_group(struct __test_metadata *_metadata, struct sock_filter filter_process[] = { BPF_STMT(BPF_LD|BPF_W|BPF_ABS, offsetof(struct seccomp_data, nr)), - BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_prctl, 0, 1), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 0, 1), BPF_STMT(BPF_RET|BPF_K, kill), BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), }; @@ -1576,7 +1583,7 @@ void start_tracer(struct __test_metadata *_metadata, int fd, pid_t tracee, ASSERT_EQ(0, ret); } /* Directly report the status of our test harness results. */ - syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); + syscall(__NR_exit, _metadata->exit_code); } /* Common tracer setup/teardown functions. */ @@ -1623,7 +1630,7 @@ void teardown_trace_fixture(struct __test_metadata *_metadata, ASSERT_EQ(0, kill(tracer, SIGUSR1)); ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); if (WEXITSTATUS(status)) - _metadata->passed = 0; + _metadata->exit_code = KSFT_FAIL; } } @@ -3088,8 +3095,7 @@ TEST(syscall_restart) } /* Directly report the status of our test harness results. */ - syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS - : EXIT_FAILURE); + syscall(__NR_exit, _metadata->exit_code); } EXPECT_EQ(0, close(pipefd[0])); @@ -3174,7 +3180,7 @@ TEST(syscall_restart) ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); if (WIFSIGNALED(status) || WEXITSTATUS(status)) - _metadata->passed = 0; + _metadata->exit_code = KSFT_FAIL; } TEST_SIGNAL(filter_flag_log, SIGSYS) @@ -3709,7 +3715,12 @@ TEST(user_notification_sibling_pid_ns) ASSERT_GE(pid, 0); if (pid == 0) { - ASSERT_EQ(unshare(CLONE_NEWPID), 0); + ASSERT_EQ(unshare(CLONE_NEWPID), 0) { + if (errno == EPERM) + SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN"); + else if (errno == EINVAL) + SKIP(return, "CLONE_NEWPID is invalid (missing CONFIG_PID_NS?)"); + } pid2 = fork(); ASSERT_GE(pid2, 0); @@ -3727,6 +3738,8 @@ TEST(user_notification_sibling_pid_ns) ASSERT_EQ(unshare(CLONE_NEWPID), 0) { if (errno == EPERM) SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN"); + else if (errno == EINVAL) + SKIP(return, "CLONE_NEWPID is invalid (missing CONFIG_PID_NS?)"); } ASSERT_EQ(errno, 0); @@ -3948,6 +3961,60 @@ TEST(user_notification_filter_empty) EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); } +TEST(user_ioctl_notification_filter_empty) +{ + pid_t pid; + long ret; + int status, p[2]; + struct __clone_args args = { + .flags = CLONE_FILES, + .exit_signal = SIGCHLD, + }; + struct seccomp_notif req = {}; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + if (__NR_clone3 < 0) + SKIP(return, "Test not built with clone3 support"); + + ASSERT_EQ(0, pipe(p)); + + pid = sys_clone3(&args, sizeof(args)); + ASSERT_GE(pid, 0); + + if (pid == 0) { + int listener; + + listener = user_notif_syscall(__NR_mknodat, SECCOMP_FILTER_FLAG_NEW_LISTENER); + if (listener < 0) + _exit(EXIT_FAILURE); + + if (dup2(listener, 200) != 200) + _exit(EXIT_FAILURE); + close(p[1]); + close(listener); + sleep(1); + + _exit(EXIT_SUCCESS); + } + if (read(p[0], &status, 1) != 0) + _exit(EXIT_SUCCESS); + close(p[0]); + /* + * The seccomp filter has become unused so we should be notified once + * the kernel gets around to cleaning up task struct. + */ + EXPECT_EQ(ioctl(200, SECCOMP_IOCTL_NOTIF_RECV, &req), -1); + EXPECT_EQ(errno, ENOENT); + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); +} + static void *do_thread(void *data) { return NULL; @@ -4037,6 +4104,16 @@ TEST(user_notification_filter_empty_threaded) EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); } + +int get_next_fd(int prev_fd) +{ + for (int i = prev_fd + 1; i < FD_SETSIZE; ++i) { + if (fcntl(i, F_GETFD) == -1) + return i; + } + _exit(EXIT_FAILURE); +} + TEST(user_notification_addfd) { pid_t pid; @@ -4053,7 +4130,7 @@ TEST(user_notification_addfd) /* There may be arbitrary already-open fds at test start. */ memfd = memfd_create("test", 0); ASSERT_GE(memfd, 0); - nextfd = memfd + 1; + nextfd = get_next_fd(memfd); ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); ASSERT_EQ(0, ret) { @@ -4064,7 +4141,8 @@ TEST(user_notification_addfd) /* Check that the basic notification machinery works */ listener = user_notif_syscall(__NR_getppid, SECCOMP_FILTER_FLAG_NEW_LISTENER); - ASSERT_EQ(listener, nextfd++); + ASSERT_EQ(listener, nextfd); + nextfd = get_next_fd(nextfd); pid = fork(); ASSERT_GE(pid, 0); @@ -4119,14 +4197,16 @@ TEST(user_notification_addfd) /* Verify we can set an arbitrary remote fd */ fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); - EXPECT_EQ(fd, nextfd++); + EXPECT_EQ(fd, nextfd); + nextfd = get_next_fd(nextfd); EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); /* Verify we can set an arbitrary remote fd with large size */ memset(&big, 0x0, sizeof(big)); big.addfd = addfd; fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big); - EXPECT_EQ(fd, nextfd++); + EXPECT_EQ(fd, nextfd); + nextfd = get_next_fd(nextfd); /* Verify we can set a specific remote fd */ addfd.newfd = 42; @@ -4164,7 +4244,8 @@ TEST(user_notification_addfd) * Child has earlier "low" fds and now 42, so we expect the next * lowest available fd to be assigned here. */ - EXPECT_EQ(fd, nextfd++); + EXPECT_EQ(fd, nextfd); + nextfd = get_next_fd(nextfd); ASSERT_EQ(filecmp(getpid(), pid, memfd, fd), 0); /* @@ -4735,6 +4816,277 @@ TEST(user_notification_wait_killable_fatal) EXPECT_EQ(SIGTERM, WTERMSIG(status)); } +struct tsync_vs_thread_leader_args { + pthread_t leader; +}; + +static void *tsync_vs_dead_thread_leader_sibling(void *_args) +{ + struct sock_filter allow_filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog allow_prog = { + .len = (unsigned short)ARRAY_SIZE(allow_filter), + .filter = allow_filter, + }; + struct tsync_vs_thread_leader_args *args = _args; + void *retval; + long ret; + + ret = pthread_join(args->leader, &retval); + if (ret) + exit(1); + if (retval != _args) + exit(2); + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, &allow_prog); + if (ret) + exit(3); + + exit(0); +} + +/* + * Ensure that a dead thread leader doesn't prevent installing new filters with + * SECCOMP_FILTER_FLAG_TSYNC from other threads. + */ +TEST(tsync_vs_dead_thread_leader) +{ + int status; + pid_t pid; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + struct sock_filter allow_filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog allow_prog = { + .len = (unsigned short)ARRAY_SIZE(allow_filter), + .filter = allow_filter, + }; + struct tsync_vs_thread_leader_args *args; + pthread_t sibling; + + args = malloc(sizeof(*args)); + ASSERT_NE(NULL, args); + args->leader = pthread_self(); + + ret = pthread_create(&sibling, NULL, + tsync_vs_dead_thread_leader_sibling, args); + ASSERT_EQ(0, ret); + + /* Install a new filter just to the leader thread. */ + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &allow_prog); + ASSERT_EQ(0, ret); + pthread_exit(args); + exit(1); + } + + EXPECT_EQ(pid, waitpid(pid, &status, 0)); + EXPECT_EQ(0, status); +} + +noinline int probed(void) +{ + return 1; +} + +static int parse_uint_from_file(const char *file, const char *fmt) +{ + int err = -1, ret; + FILE *f; + + f = fopen(file, "re"); + if (f) { + err = fscanf(f, fmt, &ret); + fclose(f); + } + return err == 1 ? ret : err; +} + +static int determine_uprobe_perf_type(void) +{ + const char *file = "/sys/bus/event_source/devices/uprobe/type"; + + return parse_uint_from_file(file, "%d\n"); +} + +static int determine_uprobe_retprobe_bit(void) +{ + const char *file = "/sys/bus/event_source/devices/uprobe/format/retprobe"; + + return parse_uint_from_file(file, "config:%d\n"); +} + +static ssize_t get_uprobe_offset(const void *addr) +{ + size_t start, base, end; + bool found = false; + char buf[256]; + FILE *f; + + f = fopen("/proc/self/maps", "r"); + if (!f) + return -1; + + while (fscanf(f, "%zx-%zx %s %zx %*[^\n]\n", &start, &end, buf, &base) == 4) { + if (buf[2] == 'x' && (uintptr_t)addr >= start && (uintptr_t)addr < end) { + found = true; + break; + } + } + fclose(f); + return found ? (uintptr_t)addr - start + base : -1; +} + +FIXTURE(URETPROBE) { + int fd; +}; + +FIXTURE_VARIANT(URETPROBE) { + /* + * All of the URETPROBE behaviors can be tested with either + * uretprobe attached or not + */ + bool attach; +}; + +FIXTURE_VARIANT_ADD(URETPROBE, attached) { + .attach = true, +}; + +FIXTURE_VARIANT_ADD(URETPROBE, not_attached) { + .attach = false, +}; + +FIXTURE_SETUP(URETPROBE) +{ + const size_t attr_sz = sizeof(struct perf_event_attr); + struct perf_event_attr attr; + ssize_t offset; + int type, bit; + +#ifndef __NR_uretprobe + SKIP(return, "__NR_uretprobe syscall not defined"); +#endif + + if (!variant->attach) + return; + + memset(&attr, 0, attr_sz); + + type = determine_uprobe_perf_type(); + ASSERT_GE(type, 0); + bit = determine_uprobe_retprobe_bit(); + ASSERT_GE(bit, 0); + offset = get_uprobe_offset(probed); + ASSERT_GE(offset, 0); + + attr.config |= 1 << bit; + attr.size = attr_sz; + attr.type = type; + attr.config1 = ptr_to_u64("/proc/self/exe"); + attr.config2 = offset; + + self->fd = syscall(__NR_perf_event_open, &attr, + getpid() /* pid */, -1 /* cpu */, -1 /* group_fd */, + PERF_FLAG_FD_CLOEXEC); +} + +FIXTURE_TEARDOWN(URETPROBE) +{ + /* we could call close(self->fd), but we'd need extra filter for + * that and since we are calling _exit right away.. + */ +} + +static int run_probed_with_filter(struct sock_fprog *prog) +{ + if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) || + seccomp(SECCOMP_SET_MODE_FILTER, 0, prog)) { + return -1; + } + + probed(); + return 0; +} + +TEST_F(URETPROBE, uretprobe_default_allow) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + ASSERT_EQ(0, run_probed_with_filter(&prog)); +} + +TEST_F(URETPROBE, uretprobe_default_block) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit_group, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + ASSERT_EQ(0, run_probed_with_filter(&prog)); +} + +TEST_F(URETPROBE, uretprobe_block_uretprobe_syscall) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), +#ifdef __NR_uretprobe + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_uretprobe, 0, 1), +#endif + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + ASSERT_EQ(0, run_probed_with_filter(&prog)); +} + +TEST_F(URETPROBE, uretprobe_default_block_with_uretprobe_syscall) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), +#ifdef __NR_uretprobe + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_uretprobe, 2, 0), +#endif + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit_group, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + ASSERT_EQ(0, run_probed_with_filter(&prog)); +} + /* * TODO: * - expand NNP testing |