diff options
Diffstat (limited to 'tools/testing/selftests/seccomp/seccomp_bpf.c')
| -rw-r--r-- | tools/testing/selftests/seccomp/seccomp_bpf.c | 2109 |
1 files changed, 2109 insertions, 0 deletions
diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c new file mode 100644 index 000000000000..c5abe7fd7590 --- /dev/null +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -0,0 +1,2109 @@ +/* + * Copyright (c) 2012 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by the GPLv2 license. + * + * Test code for seccomp bpf. + */ + +#include <asm/siginfo.h> +#define __have_siginfo_t 1 +#define __have_sigval_t 1 +#define __have_sigevent_t 1 + +#include <errno.h> +#include <linux/filter.h> +#include <sys/prctl.h> +#include <sys/ptrace.h> +#include <sys/user.h> +#include <linux/prctl.h> +#include <linux/ptrace.h> +#include <linux/seccomp.h> +#include <poll.h> +#include <pthread.h> +#include <semaphore.h> +#include <signal.h> +#include <stddef.h> +#include <stdbool.h> +#include <string.h> +#include <linux/elf.h> +#include <sys/uio.h> + +#define _GNU_SOURCE +#include <unistd.h> +#include <sys/syscall.h> + +#include "test_harness.h" + +#ifndef PR_SET_PTRACER +# define PR_SET_PTRACER 0x59616d61 +#endif + +#ifndef PR_SET_NO_NEW_PRIVS +#define PR_SET_NO_NEW_PRIVS 38 +#define PR_GET_NO_NEW_PRIVS 39 +#endif + +#ifndef PR_SECCOMP_EXT +#define PR_SECCOMP_EXT 43 +#endif + +#ifndef SECCOMP_EXT_ACT +#define SECCOMP_EXT_ACT 1 +#endif + +#ifndef SECCOMP_EXT_ACT_TSYNC +#define SECCOMP_EXT_ACT_TSYNC 1 +#endif + +#ifndef SECCOMP_MODE_STRICT +#define SECCOMP_MODE_STRICT 1 +#endif + +#ifndef SECCOMP_MODE_FILTER +#define SECCOMP_MODE_FILTER 2 +#endif + +#ifndef SECCOMP_RET_KILL +#define SECCOMP_RET_KILL 0x00000000U /* kill the task immediately */ +#define SECCOMP_RET_TRAP 0x00030000U /* disallow and force a SIGSYS */ +#define SECCOMP_RET_ERRNO 0x00050000U /* returns an errno */ +#define SECCOMP_RET_TRACE 0x7ff00000U /* pass to a tracer or disallow */ +#define SECCOMP_RET_ALLOW 0x7fff0000U /* allow */ + +/* Masks for the return value sections. */ +#define SECCOMP_RET_ACTION 0x7fff0000U +#define SECCOMP_RET_DATA 0x0000ffffU + +struct seccomp_data { + int nr; + __u32 arch; + __u64 instruction_pointer; + __u64 args[6]; +}; +#endif + +#define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) + +#define SIBLING_EXIT_UNKILLED 0xbadbeef +#define SIBLING_EXIT_FAILURE 0xbadface +#define SIBLING_EXIT_NEWPRIVS 0xbadfeed + +TEST(mode_strict_support) +{ + long ret; + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support CONFIG_SECCOMP"); + } + syscall(__NR_exit, 1); +} + +TEST_SIGNAL(mode_strict_cannot_call_prctl, SIGKILL) +{ + long ret; + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, NULL, NULL); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support CONFIG_SECCOMP"); + } + syscall(__NR_prctl, PR_SET_SECCOMP, SECCOMP_MODE_FILTER, + NULL, NULL, NULL); + EXPECT_FALSE(true) { + TH_LOG("Unreachable!"); + } +} + +/* Note! This doesn't test no new privs behavior */ +TEST(no_new_privs_support) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + EXPECT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } +} + +/* Tests kernel support by checking for a copy_from_user() fault on * NULL. */ +TEST(mode_filter_support) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EFAULT, errno) { + TH_LOG("Kernel does not support CONFIG_SECCOMP_FILTER!"); + } +} + +TEST(mode_filter_without_nnp) +{ + 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, + }; + long ret; + + ret = prctl(PR_GET_NO_NEW_PRIVS, 0, NULL, 0, 0); + ASSERT_LE(0, ret) { + TH_LOG("Expected 0 or unsupported for NO_NEW_PRIVS"); + } + errno = 0; + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + /* Succeeds with CAP_SYS_ADMIN, fails without */ + /* TODO(wad) check caps not euid */ + if (geteuid()) { + EXPECT_EQ(-1, ret); + EXPECT_EQ(EACCES, errno); + } else { + EXPECT_EQ(0, ret); + } +} + +#define MAX_INSNS_PER_PATH 32768 + +TEST(filter_size_limits) +{ + int i; + int count = BPF_MAXINSNS + 1; + struct sock_filter allow[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter *filter; + struct sock_fprog prog = { }; + long ret; + + filter = calloc(count, sizeof(*filter)); + ASSERT_NE(NULL, filter); + + for (i = 0; i < count; i++) + filter[i] = allow[0]; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + prog.filter = filter; + prog.len = count; + + /* Too many filter instructions in a single filter. */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_NE(0, ret) { + TH_LOG("Installing %d insn filter was allowed", prog.len); + } + + /* One less is okay, though. */ + prog.len -= 1; + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Installing %d insn filter wasn't allowed", prog.len); + } +} + +TEST(filter_chain_limits) +{ + int i; + int count = BPF_MAXINSNS; + struct sock_filter allow[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter *filter; + struct sock_fprog prog = { }; + long ret; + + filter = calloc(count, sizeof(*filter)); + ASSERT_NE(NULL, filter); + + for (i = 0; i < count; i++) + filter[i] = allow[0]; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + prog.filter = filter; + prog.len = 1; + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); + + prog.len = count; + + /* Too many total filter instructions. */ + for (i = 0; i < MAX_INSNS_PER_PATH; i++) { + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + if (ret != 0) + break; + } + ASSERT_NE(0, ret) { + TH_LOG("Allowed %d %d-insn filters (total with penalties:%d)", + i, count, i * (count + 4)); + } +} + +TEST(mode_filter_cannot_move_to_strict) +{ + 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, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, NULL, 0, 0); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno); +} + + +TEST(mode_filter_get_seccomp) +{ + 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, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); + EXPECT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_GET_SECCOMP, 0, 0, 0, 0); + EXPECT_EQ(2, ret); +} + + +TEST(ALLOW_all) +{ + 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, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); +} + +TEST(empty_prog) +{ + struct sock_filter filter[] = { + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno); +} + +TEST_SIGNAL(unknown_ret_is_kill_inside, SIGSYS) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, 0x10000000U), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + EXPECT_EQ(0, syscall(__NR_getpid)) { + TH_LOG("getpid() shouldn't ever return"); + } +} + +/* return code >= 0x80000000 is unused. */ +TEST_SIGNAL(unknown_ret_is_kill_above_allow, SIGSYS) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, 0x90000000U), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + EXPECT_EQ(0, syscall(__NR_getpid)) { + TH_LOG("getpid() shouldn't ever return"); + } +} + +TEST_SIGNAL(KILL_all, SIGSYS) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); +} + +TEST_SIGNAL(KILL_one, SIGSYS) +{ + 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_getpid, 0, 1), + 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, + }; + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_SIGNAL(KILL_one_arg_one, SIGSYS) +{ + 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_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + /* Only both with lower 32-bit for now. */ + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(0)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1), + 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, + }; + long ret; + pid_t parent = getppid(); + pid_t pid = getpid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(pid, syscall(__NR_getpid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid, 0x0C0FFEE)); +} + +TEST_SIGNAL(KILL_one_arg_six, SIGSYS) +{ + 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_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + /* Only both with lower 32-bit for now. */ + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(5)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 0x0C0FFEE, 0, 1), + 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, + }; + long ret; + pid_t parent = getppid(); + pid_t pid = getpid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(pid, syscall(__NR_getpid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid, 1, 2, 3, 4, 5, 0x0C0FFEE)); +} + +/* TODO(wad) add 64-bit versus 32-bit arg tests. */ +TEST(arg_out_of_range) +{ + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, syscall_arg(6)), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + EXPECT_EQ(-1, ret); + EXPECT_EQ(EINVAL, errno); +} + +TEST(ERRNO_valid) +{ + 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_read, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | E2BIG), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(-1, read(0, NULL, 0)); + EXPECT_EQ(E2BIG, errno); +} + +TEST(ERRNO_zero) +{ + 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_read, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* "errno" of 0 is ok. */ + EXPECT_EQ(0, read(0, NULL, 0)); +} + +TEST(ERRNO_capped) +{ + 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_read, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | 4096), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; + pid_t parent = getppid(); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + ASSERT_EQ(0, ret); + + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(-1, read(0, NULL, 0)); + EXPECT_EQ(4095, errno); +} + +FIXTURE_DATA(TRAP) { + struct sock_fprog prog; +}; + +FIXTURE_SETUP(TRAP) +{ + 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_getpid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + + memset(&self->prog, 0, sizeof(self->prog)); + self->prog.filter = malloc(sizeof(filter)); + ASSERT_NE(NULL, self->prog.filter); + memcpy(self->prog.filter, filter, sizeof(filter)); + self->prog.len = (unsigned short)ARRAY_SIZE(filter); +} + +FIXTURE_TEARDOWN(TRAP) +{ + if (self->prog.filter) + free(self->prog.filter); +} + +TEST_F_SIGNAL(TRAP, dfl, SIGSYS) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); + ASSERT_EQ(0, ret); + syscall(__NR_getpid); +} + +/* Ensure that SIGSYS overrides SIG_IGN */ +TEST_F_SIGNAL(TRAP, ign, SIGSYS) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + signal(SIGSYS, SIG_IGN); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); + ASSERT_EQ(0, ret); + syscall(__NR_getpid); +} + +static struct siginfo TRAP_info; +static volatile int TRAP_nr; +static void TRAP_action(int nr, siginfo_t *info, void *void_context) +{ + memcpy(&TRAP_info, info, sizeof(TRAP_info)); + TRAP_nr = nr; +} + +TEST_F(TRAP, handler) +{ + int ret, test; + struct sigaction act; + sigset_t mask; + + memset(&act, 0, sizeof(act)); + sigemptyset(&mask); + sigaddset(&mask, SIGSYS); + + act.sa_sigaction = &TRAP_action; + act.sa_flags = SA_SIGINFO; + ret = sigaction(SIGSYS, &act, NULL); + ASSERT_EQ(0, ret) { + TH_LOG("sigaction failed"); + } + ret = sigprocmask(SIG_UNBLOCK, &mask, NULL); + ASSERT_EQ(0, ret) { + TH_LOG("sigprocmask failed"); + } + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog); + ASSERT_EQ(0, ret); + TRAP_nr = 0; + memset(&TRAP_info, 0, sizeof(TRAP_info)); + /* Expect the registers to be rolled back. (nr = error) may vary + * based on arch. */ + ret = syscall(__NR_getpid); + /* Silence gcc warning about volatile. */ + test = TRAP_nr; + EXPECT_EQ(SIGSYS, test); + struct local_sigsys { + void *_call_addr; /* calling user insn */ + int _syscall; /* triggering system call number */ + unsigned int _arch; /* AUDIT_ARCH_* of syscall */ + } *sigsys = (struct local_sigsys *) +#ifdef si_syscall + &(TRAP_info.si_call_addr); +#else + &TRAP_info.si_pid; +#endif + EXPECT_EQ(__NR_getpid, sigsys->_syscall); + /* Make sure arch is non-zero. */ + EXPECT_NE(0, sigsys->_arch); + EXPECT_NE(0, (unsigned long)sigsys->_call_addr); +} + +FIXTURE_DATA(precedence) { + struct sock_fprog allow; + struct sock_fprog trace; + struct sock_fprog error; + struct sock_fprog trap; + struct sock_fprog kill; +}; + +FIXTURE_SETUP(precedence) +{ + struct sock_filter allow_insns[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter trace_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE), + }; + struct sock_filter error_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO), + }; + struct sock_filter trap_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRAP), + }; + struct sock_filter kill_insns[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getpid, 1, 0), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + }; + + memset(self, 0, sizeof(*self)); +#define FILTER_ALLOC(_x) \ + self->_x.filter = malloc(sizeof(_x##_insns)); \ + ASSERT_NE(NULL, self->_x.filter); \ + memcpy(self->_x.filter, &_x##_insns, sizeof(_x##_insns)); \ + self->_x.len = (unsigned short)ARRAY_SIZE(_x##_insns) + FILTER_ALLOC(allow); + FILTER_ALLOC(trace); + FILTER_ALLOC(error); + FILTER_ALLOC(trap); + FILTER_ALLOC(kill); +} + +FIXTURE_TEARDOWN(precedence) +{ +#define FILTER_FREE(_x) if (self->_x.filter) free(self->_x.filter) + FILTER_FREE(allow); + FILTER_FREE(trace); + FILTER_FREE(error); + FILTER_FREE(trap); + FILTER_FREE(kill); +} + +TEST_F(precedence, allow_ok) +{ + pid_t parent, res = 0; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + res = syscall(__NR_getppid); + EXPECT_EQ(parent, res); +} + +TEST_F_SIGNAL(precedence, kill_is_highest, SIGSYS) +{ + pid_t parent, res = 0; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + res = syscall(__NR_getppid); + EXPECT_EQ(parent, res); + /* getpid() should never return. */ + res = syscall(__NR_getpid); + EXPECT_EQ(0, res); +} + +TEST_F_SIGNAL(precedence, kill_is_highest_in_any_order, SIGSYS) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->kill); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F_SIGNAL(precedence, trap_is_second, SIGSYS) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F_SIGNAL(precedence, trap_is_second_in_any_order, SIGSYS) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trap); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* getpid() should never return. */ + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F(precedence, errno_is_third) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F(precedence, errno_is_third_in_any_order) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->error); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + EXPECT_EQ(0, syscall(__NR_getpid)); +} + +TEST_F(precedence, trace_is_fourth) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* No ptracer */ + EXPECT_EQ(-1, syscall(__NR_getpid)); +} + +TEST_F(precedence, trace_is_fourth_in_any_order) +{ + pid_t parent; + long ret; + + parent = getppid(); + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->trace); + ASSERT_EQ(0, ret); + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->allow); + ASSERT_EQ(0, ret); + /* Should work just fine. */ + EXPECT_EQ(parent, syscall(__NR_getppid)); + /* No ptracer */ + EXPECT_EQ(-1, syscall(__NR_getpid)); +} + +#ifndef PTRACE_O_TRACESECCOMP +#define PTRACE_O_TRACESECCOMP 0x00000080 +#endif + +/* Catch the Ubuntu 12.04 value error. */ +#if PTRACE_EVENT_SECCOMP != 7 +#undef PTRACE_EVENT_SECCOMP +#endif + +#ifndef PTRACE_EVENT_SECCOMP +#define PTRACE_EVENT_SECCOMP 7 +#endif + +#define IS_SECCOMP_EVENT(status) ((status >> 16) == PTRACE_EVENT_SECCOMP) +bool tracer_running; +void tracer_stop(int sig) +{ + tracer_running = false; +} + +typedef void tracer_func_t(struct __test_metadata *_metadata, + pid_t tracee, int status, void *args); + +void tracer(struct __test_metadata *_metadata, int fd, pid_t tracee, + tracer_func_t tracer_func, void *args) +{ + int ret = -1; + struct sigaction action = { + .sa_handler = tracer_stop, + }; + + /* Allow external shutdown. */ + tracer_running = true; + ASSERT_EQ(0, sigaction(SIGUSR1, &action, NULL)); + + errno = 0; + while (ret == -1 && errno != EINVAL) + ret = ptrace(PTRACE_ATTACH, tracee, NULL, 0); + ASSERT_EQ(0, ret) { + kill(tracee, SIGKILL); + } + /* Wait for attach stop */ + wait(NULL); + + ret = ptrace(PTRACE_SETOPTIONS, tracee, NULL, PTRACE_O_TRACESECCOMP); + ASSERT_EQ(0, ret) { + TH_LOG("Failed to set PTRACE_O_TRACESECCOMP"); + kill(tracee, SIGKILL); + } + ptrace(PTRACE_CONT, tracee, NULL, 0); + + /* Unblock the tracee */ + ASSERT_EQ(1, write(fd, "A", 1)); + ASSERT_EQ(0, close(fd)); + + /* Run until we're shut down. Must assert to stop execution. */ + while (tracer_running) { + int status; + + if (wait(&status) != tracee) + continue; + if (WIFSIGNALED(status) || WIFEXITED(status)) + /* Child is dead. Time to go. */ + return; + + /* Make sure this is a seccomp event. */ + ASSERT_EQ(true, IS_SECCOMP_EVENT(status)); + + tracer_func(_metadata, tracee, status, args); + + ret = ptrace(PTRACE_CONT, tracee, NULL, NULL); + ASSERT_EQ(0, ret); + } + /* Directly report the status of our test harness results. */ + syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); +} + +/* Common tracer setup/teardown functions. */ +void cont_handler(int num) +{ } +pid_t setup_trace_fixture(struct __test_metadata *_metadata, + tracer_func_t func, void *args) +{ + char sync; + int pipefd[2]; + pid_t tracer_pid; + pid_t tracee = getpid(); + + /* Setup a pipe for clean synchronization. */ + ASSERT_EQ(0, pipe(pipefd)); + + /* Fork a child which we'll promote to tracer */ + tracer_pid = fork(); + ASSERT_LE(0, tracer_pid); + signal(SIGALRM, cont_handler); + if (tracer_pid == 0) { + close(pipefd[0]); + tracer(_metadata, pipefd[1], tracee, func, args); + syscall(__NR_exit, 0); + } + close(pipefd[1]); + prctl(PR_SET_PTRACER, tracer_pid, 0, 0, 0); + read(pipefd[0], &sync, 1); + close(pipefd[0]); + + return tracer_pid; +} +void teardown_trace_fixture(struct __test_metadata *_metadata, + pid_t tracer) +{ + 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->passed = 0; + } +} + +/* "poke" tracer arguments and function. */ +struct tracer_args_poke_t { + unsigned long poke_addr; +}; + +void tracer_poke(struct __test_metadata *_metadata, pid_t tracee, int status, + void *args) +{ + int ret; + unsigned long msg; + struct tracer_args_poke_t *info = (struct tracer_args_poke_t *)args; + + ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); + EXPECT_EQ(0, ret); + /* If this fails, don't try to recover. */ + ASSERT_EQ(0x1001, msg) { + kill(tracee, SIGKILL); + } + /* + * Poke in the message. + * Registers are not touched to try to keep this relatively arch + * agnostic. + */ + ret = ptrace(PTRACE_POKEDATA, tracee, info->poke_addr, 0x1001); + EXPECT_EQ(0, ret); +} + +FIXTURE_DATA(TRACE_poke) { + struct sock_fprog prog; + pid_t tracer; + long poked; + struct tracer_args_poke_t tracer_args; +}; + +FIXTURE_SETUP(TRACE_poke) +{ + 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_read, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1001), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + + self->poked = 0; + memset(&self->prog, 0, sizeof(self->prog)); + self->prog.filter = malloc(sizeof(filter)); + ASSERT_NE(NULL, self->prog.filter); + memcpy(self->prog.filter, filter, sizeof(filter)); + self->prog.len = (unsigned short)ARRAY_SIZE(filter); + + /* Set up tracer args. */ + self->tracer_args.poke_addr = (unsigned long)&self->poked; + + /* Launch tracer. */ + self->tracer = setup_trace_fixture(_metadata, tracer_poke, + &self->tracer_args); +} + +FIXTURE_TEARDOWN(TRACE_poke) +{ + teardown_trace_fixture(_metadata, self->tracer); + if (self->prog.filter) + free(self->prog.filter); +} + +TEST_F(TRACE_poke, read_has_side_effects) +{ + ssize_t ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); + ASSERT_EQ(0, ret); + + EXPECT_EQ(0, self->poked); + ret = read(-1, NULL, 0); + EXPECT_EQ(-1, ret); + EXPECT_EQ(0x1001, self->poked); +} + +TEST_F(TRACE_poke, getpid_runs_normally) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); + ASSERT_EQ(0, ret); + + EXPECT_EQ(0, self->poked); + EXPECT_NE(0, syscall(__NR_getpid)); + EXPECT_EQ(0, self->poked); +} + +#if defined(__x86_64__) +# define ARCH_REGS struct user_regs_struct +# define SYSCALL_NUM orig_rax +# define SYSCALL_RET rax +#elif defined(__i386__) +# define ARCH_REGS struct user_regs_struct +# define SYSCALL_NUM orig_eax +# define SYSCALL_RET eax +#elif defined(__arm__) +# define ARCH_REGS struct pt_regs +# define SYSCALL_NUM ARM_r7 +# define SYSCALL_RET ARM_r0 +#elif defined(__aarch64__) +# define ARCH_REGS struct user_pt_regs +# define SYSCALL_NUM regs[8] +# define SYSCALL_RET regs[0] +#else +# error "Do not know how to find your architecture's registers and syscalls" +#endif + +/* Architecture-specific syscall fetching routine. */ +int get_syscall(struct __test_metadata *_metadata, pid_t tracee) +{ + struct iovec iov; + ARCH_REGS regs; + + iov.iov_base = ®s; + iov.iov_len = sizeof(regs); + EXPECT_EQ(0, ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov)) { + TH_LOG("PTRACE_GETREGSET failed"); + return -1; + } + + return regs.SYSCALL_NUM; +} + +/* Architecture-specific syscall changing routine. */ +void change_syscall(struct __test_metadata *_metadata, + pid_t tracee, int syscall) +{ + struct iovec iov; + int ret; + ARCH_REGS regs; + + iov.iov_base = ®s; + iov.iov_len = sizeof(regs); + ret = ptrace(PTRACE_GETREGSET, tracee, NT_PRSTATUS, &iov); + EXPECT_EQ(0, ret); + +#if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__) + { + regs.SYSCALL_NUM = syscall; + } + +#elif defined(__arm__) +# ifndef PTRACE_SET_SYSCALL +# define PTRACE_SET_SYSCALL 23 +# endif + { + ret = ptrace(PTRACE_SET_SYSCALL, tracee, NULL, syscall); + EXPECT_EQ(0, ret); + } + +#else + ASSERT_EQ(1, 0) { + TH_LOG("How is the syscall changed on this architecture?"); + } +#endif + + /* If syscall is skipped, change return value. */ + if (syscall == -1) + regs.SYSCALL_RET = 1; + + ret = ptrace(PTRACE_SETREGSET, tracee, NT_PRSTATUS, &iov); + EXPECT_EQ(0, ret); +} + +void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee, + int status, void *args) +{ + int ret; + unsigned long msg; + + /* Make sure we got the right message. */ + ret = ptrace(PTRACE_GETEVENTMSG, tracee, NULL, &msg); + EXPECT_EQ(0, ret); + + switch (msg) { + case 0x1002: + /* change getpid to getppid. */ + change_syscall(_metadata, tracee, __NR_getppid); + break; + case 0x1003: + /* skip gettid. */ + change_syscall(_metadata, tracee, -1); + break; + case 0x1004: + /* do nothing (allow getppid) */ + break; + default: + EXPECT_EQ(0, msg) { + TH_LOG("Unknown PTRACE_GETEVENTMSG: 0x%lx", msg); + kill(tracee, SIGKILL); + } + } + +} + +FIXTURE_DATA(TRACE_syscall) { + struct sock_fprog prog; + pid_t tracer, mytid, mypid, parent; +}; + +FIXTURE_SETUP(TRACE_syscall) +{ + 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_getpid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1002), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_gettid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1003), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1004), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + + memset(&self->prog, 0, sizeof(self->prog)); + self->prog.filter = malloc(sizeof(filter)); + ASSERT_NE(NULL, self->prog.filter); + memcpy(self->prog.filter, filter, sizeof(filter)); + self->prog.len = (unsigned short)ARRAY_SIZE(filter); + + /* Prepare some testable syscall results. */ + self->mytid = syscall(__NR_gettid); + ASSERT_GT(self->mytid, 0); + ASSERT_NE(self->mytid, 1) { + TH_LOG("Running this test as init is not supported. :)"); + } + + self->mypid = getpid(); + ASSERT_GT(self->mypid, 0); + ASSERT_EQ(self->mytid, self->mypid); + + self->parent = getppid(); + ASSERT_GT(self->parent, 0); + ASSERT_NE(self->parent, self->mypid); + + /* Launch tracer. */ + self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL); +} + +FIXTURE_TEARDOWN(TRACE_syscall) +{ + teardown_trace_fixture(_metadata, self->tracer); + if (self->prog.filter) + free(self->prog.filter); +} + +TEST_F(TRACE_syscall, syscall_allowed) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); + ASSERT_EQ(0, ret); + + /* getppid works as expected (no changes). */ + EXPECT_EQ(self->parent, syscall(__NR_getppid)); + EXPECT_NE(self->mypid, syscall(__NR_getppid)); +} + +TEST_F(TRACE_syscall, syscall_redirected) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); + ASSERT_EQ(0, ret); + + /* getpid has been redirected to getppid as expected. */ + EXPECT_EQ(self->parent, syscall(__NR_getpid)); + EXPECT_NE(self->mypid, syscall(__NR_getpid)); +} + +TEST_F(TRACE_syscall, syscall_dropped) +{ + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); + ASSERT_EQ(0, ret); + + /* gettid has been skipped and an altered return value stored. */ + EXPECT_EQ(1, syscall(__NR_gettid)); + EXPECT_NE(self->mytid, syscall(__NR_gettid)); +} + +#ifndef __NR_seccomp +# if defined(__i386__) +# define __NR_seccomp 354 +# elif defined(__x86_64__) +# define __NR_seccomp 317 +# elif defined(__arm__) +# define __NR_seccomp 383 +# elif defined(__aarch64__) +# define __NR_seccomp 277 +# else +# warning "seccomp syscall number unknown for this architecture" +# define __NR_seccomp 0xffff +# endif +#endif + +#ifndef SECCOMP_SET_MODE_STRICT +#define SECCOMP_SET_MODE_STRICT 0 +#endif + +#ifndef SECCOMP_SET_MODE_FILTER +#define SECCOMP_SET_MODE_FILTER 1 +#endif + +#ifndef SECCOMP_FLAG_FILTER_TSYNC +#define SECCOMP_FLAG_FILTER_TSYNC 1 +#endif + +#ifndef seccomp +int seccomp(unsigned int op, unsigned int flags, struct sock_fprog *filter) +{ + errno = 0; + return syscall(__NR_seccomp, op, flags, filter); +} +#endif + +TEST(seccomp_syscall) +{ + 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, + }; + 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!"); + } + + /* Reject insane operation. */ + ret = seccomp(-1, 0, &prog); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Did not reject crazy op value!"); + } + + /* Reject strict with flags or pointer. */ + ret = seccomp(SECCOMP_SET_MODE_STRICT, -1, NULL); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Did not reject mode strict with flags!"); + } + ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, &prog); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Did not reject mode strict with uargs!"); + } + + /* Reject insane args for filter. */ + ret = seccomp(SECCOMP_SET_MODE_FILTER, -1, &prog); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Did not reject crazy filter flags!"); + } + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, NULL); + EXPECT_EQ(EFAULT, errno) { + TH_LOG("Did not reject NULL filter!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); + EXPECT_EQ(0, errno) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER: %s", + strerror(errno)); + } +} + +TEST(seccomp_syscall_mode_lock) +{ + 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, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); + EXPECT_EQ(0, ret) { + TH_LOG("Could not install filter!"); + } + + /* Make sure neither entry point will switch to strict. */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_STRICT, 0, 0, 0); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Switched to mode strict!"); + } + + ret = seccomp(SECCOMP_SET_MODE_STRICT, 0, NULL); + EXPECT_EQ(EINVAL, errno) { + TH_LOG("Switched to mode strict!"); + } +} + +TEST(TSYNC_first) +{ + 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, + }; + long ret; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC, + &prog); + EXPECT_EQ(0, ret) { + TH_LOG("Could not install initial filter with TSYNC!"); + } +} + +#define TSYNC_SIBLINGS 2 +struct tsync_sibling { + pthread_t tid; + pid_t system_tid; + sem_t *started; + pthread_cond_t *cond; + pthread_mutex_t *mutex; + int diverge; + int num_waits; + struct sock_fprog *prog; + struct __test_metadata *metadata; +}; + +FIXTURE_DATA(TSYNC) { + struct sock_fprog root_prog, apply_prog; + struct tsync_sibling sibling[TSYNC_SIBLINGS]; + sem_t started; + pthread_cond_t cond; + pthread_mutex_t mutex; + int sibling_count; +}; + +FIXTURE_SETUP(TSYNC) +{ + struct sock_filter root_filter[] = { + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_filter apply_filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + + memset(&self->root_prog, 0, sizeof(self->root_prog)); + memset(&self->apply_prog, 0, sizeof(self->apply_prog)); + memset(&self->sibling, 0, sizeof(self->sibling)); + self->root_prog.filter = malloc(sizeof(root_filter)); + ASSERT_NE(NULL, self->root_prog.filter); + memcpy(self->root_prog.filter, &root_filter, sizeof(root_filter)); + self->root_prog.len = (unsigned short)ARRAY_SIZE(root_filter); + + self->apply_prog.filter = malloc(sizeof(apply_filter)); + ASSERT_NE(NULL, self->apply_prog.filter); + memcpy(self->apply_prog.filter, &apply_filter, sizeof(apply_filter)); + self->apply_prog.len = (unsigned short)ARRAY_SIZE(apply_filter); + + self->sibling_count = 0; + pthread_mutex_init(&self->mutex, NULL); + pthread_cond_init(&self->cond, NULL); + sem_init(&self->started, 0, 0); + self->sibling[0].tid = 0; + self->sibling[0].cond = &self->cond; + self->sibling[0].started = &self->started; + self->sibling[0].mutex = &self->mutex; + self->sibling[0].diverge = 0; + self->sibling[0].num_waits = 1; + self->sibling[0].prog = &self->root_prog; + self->sibling[0].metadata = _metadata; + self->sibling[1].tid = 0; + self->sibling[1].cond = &self->cond; + self->sibling[1].started = &self->started; + self->sibling[1].mutex = &self->mutex; + self->sibling[1].diverge = 0; + self->sibling[1].prog = &self->root_prog; + self->sibling[1].num_waits = 1; + self->sibling[1].metadata = _metadata; +} + +FIXTURE_TEARDOWN(TSYNC) +{ + int sib = 0; + + if (self->root_prog.filter) + free(self->root_prog.filter); + if (self->apply_prog.filter) + free(self->apply_prog.filter); + + for ( ; sib < self->sibling_count; ++sib) { + struct tsync_sibling *s = &self->sibling[sib]; + void *status; + + if (!s->tid) + continue; + if (pthread_kill(s->tid, 0)) { + pthread_cancel(s->tid); + pthread_join(s->tid, &status); + } + } + pthread_mutex_destroy(&self->mutex); + pthread_cond_destroy(&self->cond); + sem_destroy(&self->started); +} + +void *tsync_sibling(void *data) +{ + long ret = 0; + struct tsync_sibling *me = data; + + me->system_tid = syscall(__NR_gettid); + + pthread_mutex_lock(me->mutex); + if (me->diverge) { + /* Just re-apply the root prog to fork the tree */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, + me->prog, 0, 0); + } + sem_post(me->started); + /* Return outside of started so parent notices failures. */ + if (ret) { + pthread_mutex_unlock(me->mutex); + return (void *)SIBLING_EXIT_FAILURE; + } + do { + pthread_cond_wait(me->cond, me->mutex); + me->num_waits = me->num_waits - 1; + } while (me->num_waits); + pthread_mutex_unlock(me->mutex); + + ret = prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0); + if (!ret) + return (void *)SIBLING_EXIT_NEWPRIVS; + read(0, NULL, 0); + return (void *)SIBLING_EXIT_UNKILLED; +} + +void tsync_start_sibling(struct tsync_sibling *sibling) +{ + pthread_create(&sibling->tid, NULL, tsync_sibling, (void *)sibling); +} + +TEST_F(TSYNC, siblings_fail_prctl) +{ + long ret; + void *status; + 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_prctl, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EINVAL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Check prctl failure detection by requesting sib 0 diverge. */ + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog); + ASSERT_EQ(0, ret) { + TH_LOG("setting filter failed"); + } + + self->sibling[0].diverge = 1; + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + /* Signal the threads to clean up*/ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure diverging sibling failed to call prctl. */ + pthread_join(self->sibling[0].tid, &status); + EXPECT_EQ(SIBLING_EXIT_FAILURE, (long)status); + pthread_join(self->sibling[1].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); +} + +TEST_F(TSYNC, two_siblings_with_ancestor) +{ + long ret; + void *status; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); + } + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC, + &self->apply_prog); + ASSERT_EQ(0, ret) { + TH_LOG("Could install filter on all threads!"); + } + /* Tell the siblings to test the policy */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + /* Ensure they are both killed and don't exit cleanly. */ + pthread_join(self->sibling[0].tid, &status); + EXPECT_EQ(0x0, (long)status); + pthread_join(self->sibling[1].tid, &status); + EXPECT_EQ(0x0, (long)status); +} + +TEST_F(TSYNC, two_sibling_want_nnp) +{ + void *status; + + /* start siblings before any prctl() operations */ + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + /* Tell the siblings to test no policy */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure they are both upset about lacking nnp. */ + pthread_join(self->sibling[0].tid, &status); + EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); + pthread_join(self->sibling[1].tid, &status); + EXPECT_EQ(SIBLING_EXIT_NEWPRIVS, (long)status); +} + +TEST_F(TSYNC, two_siblings_with_no_filter) +{ + long ret; + void *status; + + /* start siblings before any prctl() operations */ + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC, + &self->apply_prog); + ASSERT_EQ(0, ret) { + TH_LOG("Could install filter on all threads!"); + } + + /* Tell the siblings to test the policy */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure they are both killed and don't exit cleanly. */ + pthread_join(self->sibling[0].tid, &status); + EXPECT_EQ(0x0, (long)status); + pthread_join(self->sibling[1].tid, &status); + EXPECT_EQ(0x0, (long)status); +} + +TEST_F(TSYNC, two_siblings_with_one_divergence) +{ + long ret; + void *status; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); + } + self->sibling[0].diverge = 1; + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC, + &self->apply_prog); + ASSERT_EQ(self->sibling[0].system_tid, ret) { + TH_LOG("Did not fail on diverged sibling."); + } + + /* Wake the threads */ + pthread_mutex_lock(&self->mutex); + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + + /* Ensure they are both unkilled. */ + pthread_join(self->sibling[0].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); + pthread_join(self->sibling[1].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); +} + +TEST_F(TSYNC, two_siblings_not_under_filter) +{ + long ret, sib; + void *status; + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* + * Sibling 0 will have its own seccomp policy + * and Sibling 1 will not be under seccomp at + * all. Sibling 1 will enter seccomp and 0 + * will cause failure. + */ + self->sibling[0].diverge = 1; + tsync_start_sibling(&self->sibling[0]); + tsync_start_sibling(&self->sibling[1]); + + while (self->sibling_count < TSYNC_SIBLINGS) { + sem_wait(&self->started); + self->sibling_count++; + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, 0, &self->root_prog); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support SECCOMP_SET_MODE_FILTER!"); + } + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC, + &self->apply_prog); + ASSERT_EQ(ret, self->sibling[0].system_tid) { + TH_LOG("Did not fail on diverged sibling."); + } + sib = 1; + if (ret == self->sibling[0].system_tid) + sib = 0; + + pthread_mutex_lock(&self->mutex); + + /* Increment the other siblings num_waits so we can clean up + * the one we just saw. + */ + self->sibling[!sib].num_waits += 1; + + /* Signal the thread to clean up*/ + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + pthread_join(self->sibling[sib].tid, &status); + EXPECT_EQ(SIBLING_EXIT_UNKILLED, (long)status); + /* Poll for actual task death. pthread_join doesn't guarantee it. */ + while (!kill(self->sibling[sib].system_tid, 0)) + sleep(0.1); + /* Switch to the remaining sibling */ + sib = !sib; + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC, + &self->apply_prog); + ASSERT_EQ(0, ret) { + TH_LOG("Expected the remaining sibling to sync"); + }; + + pthread_mutex_lock(&self->mutex); + + /* If remaining sibling didn't have a chance to wake up during + * the first broadcast, manually reduce the num_waits now. + */ + if (self->sibling[sib].num_waits > 1) + self->sibling[sib].num_waits = 1; + ASSERT_EQ(0, pthread_cond_broadcast(&self->cond)) { + TH_LOG("cond broadcast non-zero"); + } + pthread_mutex_unlock(&self->mutex); + pthread_join(self->sibling[sib].tid, &status); + EXPECT_EQ(0, (long)status); + /* Poll for actual task death. pthread_join doesn't guarantee it. */ + while (!kill(self->sibling[sib].system_tid, 0)) + sleep(0.1); + + ret = seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FLAG_FILTER_TSYNC, + &self->apply_prog); + ASSERT_EQ(0, ret); /* just us chickens */ +} + +/* Make sure restarted syscalls are seen directly as "restart_syscall". */ +TEST(syscall_restart) +{ + long ret; + unsigned long msg; + pid_t child_pid; + int pipefd[2]; + int status; + siginfo_t info = { }; + struct sock_filter filter[] = { + BPF_STMT(BPF_LD|BPF_W|BPF_ABS, + offsetof(struct seccomp_data, nr)), + +#ifdef __NR_sigreturn + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_sigreturn, 6, 0), +#endif + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_read, 5, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_exit, 4, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_rt_sigreturn, 3, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_poll, 4, 0), + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_restart_syscall, 4, 0), + + /* Allow __NR_write for easy logging. */ + BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_write, 0, 1), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x100), /* poll */ + BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE|0x200), /* restart */ + }; + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + + ASSERT_EQ(0, pipe(pipefd)); + + child_pid = fork(); + ASSERT_LE(0, child_pid); + if (child_pid == 0) { + /* Child uses EXPECT not ASSERT to deliver status correctly. */ + char buf = ' '; + struct pollfd fds = { + .fd = pipefd[0], + .events = POLLIN, + }; + + /* Attach parent as tracer and stop. */ + EXPECT_EQ(0, ptrace(PTRACE_TRACEME)); + EXPECT_EQ(0, raise(SIGSTOP)); + + EXPECT_EQ(0, close(pipefd[1])); + + EXPECT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + EXPECT_EQ(0, ret) { + TH_LOG("Failed to install filter!"); + } + + EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { + TH_LOG("Failed to read() sync from parent"); + } + EXPECT_EQ('.', buf) { + TH_LOG("Failed to get sync data from read()"); + } + + /* Start poll to be interrupted. */ + errno = 0; + EXPECT_EQ(1, poll(&fds, 1, -1)) { + TH_LOG("Call to poll() failed (errno %d)", errno); + } + + /* Read final sync from parent. */ + EXPECT_EQ(1, read(pipefd[0], &buf, 1)) { + TH_LOG("Failed final read() from parent"); + } + EXPECT_EQ('!', buf) { + TH_LOG("Failed to get final data from read()"); + } + + /* Directly report the status of our test harness results. */ + syscall(__NR_exit, _metadata->passed ? EXIT_SUCCESS + : EXIT_FAILURE); + } + EXPECT_EQ(0, close(pipefd[0])); + + /* Attach to child, setup options, and release. */ + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(0, ptrace(PTRACE_SETOPTIONS, child_pid, NULL, + PTRACE_O_TRACESECCOMP)); + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + ASSERT_EQ(1, write(pipefd[1], ".", 1)); + + /* Wait for poll() to start. */ + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); + ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); + ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); + ASSERT_EQ(0x100, msg); + EXPECT_EQ(__NR_poll, get_syscall(_metadata, child_pid)); + + /* Might as well check siginfo for sanity while we're here. */ + ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); + ASSERT_EQ(SIGTRAP, info.si_signo); + ASSERT_EQ(SIGTRAP | (PTRACE_EVENT_SECCOMP << 8), info.si_code); + EXPECT_EQ(0, info.si_errno); + EXPECT_EQ(getuid(), info.si_uid); + /* Verify signal delivery came from child (seccomp-triggered). */ + EXPECT_EQ(child_pid, info.si_pid); + + /* Interrupt poll with SIGSTOP (which we'll need to handle). */ + ASSERT_EQ(0, kill(child_pid, SIGSTOP)); + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(SIGSTOP, WSTOPSIG(status)); + /* Verify signal delivery came from parent now. */ + ASSERT_EQ(0, ptrace(PTRACE_GETSIGINFO, child_pid, NULL, &info)); + EXPECT_EQ(getpid(), info.si_pid); + + /* Restart poll with SIGCONT, which triggers restart_syscall. */ + ASSERT_EQ(0, kill(child_pid, SIGCONT)); + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(SIGCONT, WSTOPSIG(status)); + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + + /* Wait for restart_syscall() to start. */ + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + ASSERT_EQ(true, WIFSTOPPED(status)); + ASSERT_EQ(SIGTRAP, WSTOPSIG(status)); + ASSERT_EQ(PTRACE_EVENT_SECCOMP, (status >> 16)); + ASSERT_EQ(0, ptrace(PTRACE_GETEVENTMSG, child_pid, NULL, &msg)); + ASSERT_EQ(0x200, msg); + ret = get_syscall(_metadata, child_pid); +#if defined(__arm__) + /* FIXME: ARM does not expose true syscall in registers. */ + EXPECT_EQ(__NR_poll, ret); +#else + EXPECT_EQ(__NR_restart_syscall, ret); +#endif + + /* Write again to end poll. */ + ASSERT_EQ(0, ptrace(PTRACE_CONT, child_pid, NULL, 0)); + ASSERT_EQ(1, write(pipefd[1], "!", 1)); + EXPECT_EQ(0, close(pipefd[1])); + + ASSERT_EQ(child_pid, waitpid(child_pid, &status, 0)); + if (WIFSIGNALED(status) || WEXITSTATUS(status)) + _metadata->passed = 0; +} + +/* + * TODO: + * - add microbenchmarks + * - expand NNP testing + * - better arch-specific TRACE and TRAP handlers. + * - endianness checking when appropriate + * - 64-bit arg prodding + * - arch value testing (x86 modes especially) + * - ... + */ + +TEST_HARNESS_MAIN |