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| author |   Jann Horn <jannh@google.com> | 2022-03-19 02:08:38 +0100 |
|---|---|---|
| committer |   Kees Cook <keescook@chromium.org> | 2022-04-29 11:28:42 -0700 |
| commit | d250a3e4e5b41d9d805a8bfd2458b548d1681742 (patch) | |
| tree | aea2bb12ebaa5f47a49b0a0eee64efe1c4d9e6ca /tools | |
| parent | selftests/seccomp: Don't call read() on TTY from background pgrp (diff) | |
| download | wireguard-linux-d250a3e4e5b41d9d805a8bfd2458b548d1681742.tar.xz wireguard-linux-d250a3e4e5b41d9d805a8bfd2458b548d1681742.zip | |
selftests/seccomp: Test PTRACE_O_SUSPEND_SECCOMP without CAP_SYS_ADMIN
Add a test to check that PTRACE_O_SUSPEND_SECCOMP can't be set without
CAP_SYS_ADMIN through PTRACE_SEIZE or PTRACE_SETOPTIONS.
Signed-off-by: Jann Horn <jannh@google.com>
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/seccomp/Makefile | 1 | ||||
| -rw-r--r-- | tools/testing/selftests/seccomp/seccomp_bpf.c | 63 |
2 files changed, 64 insertions, 0 deletions
diff --git a/tools/testing/selftests/seccomp/Makefile b/tools/testing/selftests/seccomp/Makefile index 585f7a0c10cb..f017c382c036 100644 --- a/tools/testing/selftests/seccomp/Makefile +++ b/tools/testing/selftests/seccomp/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 CFLAGS += -Wl,-no-as-needed -Wall -isystem ../../../../usr/include/ LDFLAGS += -lpthread +LDLIBS += -lcap TEST_GEN_PROGS := seccomp_bpf seccomp_benchmark include ../lib.mk diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 313bb0cbfb1e..4da905180f89 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -46,6 +46,7 @@ #include <sys/ioctl.h> #include <linux/kcmp.h> #include <sys/resource.h> +#include <sys/capability.h> #include <unistd.h> #include <sys/syscall.h> @@ -4231,6 +4232,68 @@ TEST(user_notification_addfd_rlimit) close(memfd); } +/* Make sure PTRACE_O_SUSPEND_SECCOMP requires CAP_SYS_ADMIN. */ +FIXTURE(O_SUSPEND_SECCOMP) { + pid_t pid; +}; + +FIXTURE_SETUP(O_SUSPEND_SECCOMP) +{ + ERRNO_FILTER(block_read, E2BIG); + cap_value_t cap_list[] = { CAP_SYS_ADMIN }; + cap_t caps; + + self->pid = 0; + + /* make sure we don't have CAP_SYS_ADMIN */ + caps = cap_get_proc(); + ASSERT_NE(NULL, caps); + ASSERT_EQ(0, cap_set_flag(caps, CAP_EFFECTIVE, 1, cap_list, CAP_CLEAR)); + ASSERT_EQ(0, cap_set_proc(caps)); + cap_free(caps); + + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)); + ASSERT_EQ(0, prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog_block_read)); + + self->pid = fork(); + ASSERT_GE(self->pid, 0); + + if (self->pid == 0) { + while (1) + pause(); + _exit(127); + } +} + +FIXTURE_TEARDOWN(O_SUSPEND_SECCOMP) +{ + if (self->pid) + kill(self->pid, SIGKILL); +} + +TEST_F(O_SUSPEND_SECCOMP, setoptions) +{ + int wstatus; + + ASSERT_EQ(0, ptrace(PTRACE_ATTACH, self->pid, NULL, 0)); + ASSERT_EQ(self->pid, wait(&wstatus)); + ASSERT_EQ(-1, ptrace(PTRACE_SETOPTIONS, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP)); + if (errno == EINVAL) + SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)"); + ASSERT_EQ(EPERM, errno); +} + +TEST_F(O_SUSPEND_SECCOMP, seize) +{ + int ret; + + ret = ptrace(PTRACE_SEIZE, self->pid, NULL, PTRACE_O_SUSPEND_SECCOMP); + ASSERT_EQ(-1, ret); + if (errno == EINVAL) + SKIP(return, "Kernel does not support PTRACE_O_SUSPEND_SECCOMP (missing CONFIG_CHECKPOINT_RESTORE?)"); + ASSERT_EQ(EPERM, errno); +} + /* * TODO: * - expand NNP testing |