| /* seccomp_bpf_tests.c |
| * Copyright (c) 2012 The Chromium OS Authors. All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| * |
| * 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 <linux/prctl.h> |
| #include <linux/ptrace.h> |
| //#include <linux/seccomp.h> |
| #include <stddef.h> |
| #include <stdbool.h> |
| #include <string.h> |
| #include <syscall.h> |
| #include <signal.h> |
| |
| #include "test_harness.h" |
| |
| #ifndef PR_SET_NO_NEW_PRIVS |
| #define PR_SET_NO_NEW_PRIVS 38 |
| #define PR_GET_NO_NEW_PRIVS 39 |
| #endif |
| |
| #ifndef SECCOMP_MODE_STRICT |
| #define SECCOMP_MODE_STRICT 1 |
| #endif |
| |
| #ifndef SECCOMP_MODE_FILTER |
| #define SECCOMP_MODE_FILTER 2 |
| #endif |
| |
| #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]; |
| }; |
| |
| #define syscall_arg(_n) (offsetof(struct seccomp_data, args[_n])) |
| |
| TEST(mode_strict_support) { |
| int 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) { |
| int 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) { |
| int 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) { |
| int 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!"); |
| } |
| } |
| |
| /* TODO(wad) add a TEST_IF_UID() wrapper */ |
| TEST(mode_filter_without_nnp) { |
| int expect_errno = EACCES; |
| int 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"); |
| } |
| /* Succeeds with CAP_SYS_ADMIN, fails without */ |
| /* TODO(wad) check caps not euid */ |
| if (geteuid() == 0) { |
| expect_errno = EFAULT; |
| } |
| errno = 0; |
| ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, NULL, NULL, NULL); |
| EXPECT_EQ(-1, ret); |
| EXPECT_EQ(expect_errno, errno); |
| } |
| |
| 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| |
| int 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(ALLOW_all) { |
| struct sock_filter filter[] = { |
| BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW), |
| }; |
| struct sock_fprog prog = { |
| .len = (unsigned short)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| |
| int 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| |
| int 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| |
| int 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| |
| int 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| |
| int 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| pid_t pid = getpid(); |
| 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| pid_t pid = getpid(); |
| 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| int 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_one) { |
| 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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_one_ok) { |
| 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)(sizeof(filter)/sizeof(filter[0])), |
| .filter = filter, |
| }; |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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)); |
| } |
| |
| 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)(sizeof(filter)/sizeof(filter[0])); |
| } |
| |
| FIXTURE_TEARDOWN(TRAP) { |
| if (self->prog.filter) |
| free(self->prog.filter); |
| }; |
| |
| TEST_F_SIGNAL(TRAP, dfl, SIGSYS) { |
| int 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) { |
| int 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 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; |
| return; |
| } |
| |
| TEST_F(TRAP, handler) { |
| int ret; |
| 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); |
| EXPECT_EQ(SIGSYS, TRAP_nr); |
| 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)(sizeof(_x##_insns)/sizeof(_x##_insns[0])) |
| 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_SIGNAL(precedence, kill_is_highest, SIGSYS) { |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| pid_t res = 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) { |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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) { |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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) { |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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) { |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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) { |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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) { |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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) { |
| int ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); |
| pid_t parent = getppid(); |
| 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 |
| void tracer(struct __test_metadata *_metadata, pid_t tracee, unsigned long |
| poke_addr) { |
| int ret = -1; |
| 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, SIGALRM); |
| while (1) { |
| int status; |
| unsigned long msg; |
| if (wait(&status) != tracee) |
| continue; |
| if (WIFSIGNALED(status) || WIFEXITED(status)) |
| /* Child is dead. Time to go. */ |
| return; |
| 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, poke_addr, 0x1001); |
| EXPECT_EQ(0, ret); |
| ret = ptrace(PTRACE_CONT, tracee, NULL, NULL); |
| EXPECT_EQ(0, ret); |
| } |
| } |
| |
| FIXTURE_DATA(TRACE) { |
| struct sock_fprog prog; |
| pid_t tracer; |
| int poked; |
| }; |
| |
| void cont_handler(int num) { |
| } |
| |
| FIXTURE_SETUP(TRACE) { |
| 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), |
| }; |
| pid_t tracer_pid; |
| pid_t tracee = getpid(); |
| unsigned long poke_addr = (unsigned long)&self->poked; |
| 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)(sizeof(filter)/sizeof(filter[0])); |
| |
| /* 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) { |
| tracer(_metadata, tracee, poke_addr); |
| syscall(__NR_exit, 0); |
| } |
| self->tracer = tracer_pid; |
| #ifdef PR_SET_PTRACER |
| prctl(PR_SET_PTRACER, self->tracer, 0, 0, 0); |
| #endif |
| /* Install dummy handler */ |
| pause(); |
| } |
| |
| FIXTURE_TEARDOWN(TRACE) { |
| if (self->tracer) |
| kill(self->tracer, SIGKILL); |
| if (self->prog.filter) |
| free(self->prog.filter); |
| }; |
| |
| TEST_F(TRACE, read_has_side_effects) { |
| ssize_t 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, getpid_runs_normally) { |
| int 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); |
| } |
| |
| /* |
| * TODO: |
| * - add microbenchmarks |
| * - expand NNP testing |
| * - add arch-specific TRACE and TRAP handlers. |
| * - endianness checking when appropriate |
| * - 64-bit arg prodding |
| * - arch value testing (x86 modes especially) |
| * - ... |
| */ |
| |
| TEST_HARNESS_MAIN |