diff options
Diffstat (limited to 'tools/testing/selftests/seccomp/seccomp_bpf.c')
| -rw-r--r-- | tools/testing/selftests/seccomp/seccomp_bpf.c | 351 |
1 files changed, 343 insertions, 8 deletions
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 783ebce8c4de..61acbd45ffaa 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 @@ -148,6 +155,12 @@ struct seccomp_data { # endif #endif +#ifndef __NR_uretprobe +# if defined(__x86_64__) +# define __NR_uretprobe 335 +# endif +#endif + #ifndef SECCOMP_SET_MODE_STRICT #define SECCOMP_SET_MODE_STRICT 0 #endif @@ -1616,14 +1629,8 @@ void teardown_trace_fixture(struct __test_metadata *_metadata, { if (tracer) { int status; - /* - * Extract the exit code from the other process and - * adopt it for ourselves in case its asserts failed. - */ ASSERT_EQ(0, kill(tracer, SIGUSR1)); ASSERT_EQ(tracer, waitpid(tracer, &status, 0)); - if (WEXITSTATUS(status)) - _metadata->exit_code = KSFT_FAIL; } } @@ -3153,12 +3160,15 @@ TEST(syscall_restart) ret = get_syscall(_metadata, child_pid); #if defined(__arm__) /* - * FIXME: * - native ARM registers do NOT expose true syscall. * - compat ARM registers on ARM64 DO expose true syscall. + * - values of utsbuf.machine include 'armv8l' or 'armb8b' + * for ARM64 running in compat mode. */ ASSERT_EQ(0, uname(&utsbuf)); - if (strncmp(utsbuf.machine, "arm", 3) == 0) { + if ((strncmp(utsbuf.machine, "arm", 3) == 0) && + (strncmp(utsbuf.machine, "armv8l", 6) != 0) && + (strncmp(utsbuf.machine, "armv8b", 6) != 0)) { EXPECT_EQ(__NR_nanosleep, ret); } else #endif @@ -3954,6 +3964,60 @@ 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; @@ -4755,6 +4819,277 @@ 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 |