On 19/04/2017 01:16, Kees Cook wrote: > On Tue, Mar 28, 2017 at 4:46 PM, Mickaël Salaün wrote: >> Test basic context access, ptrace protection and filesystem event with >> multiple cases. >> >> Changes since v5: >> * add subtype test >> * add ptrace tests >> * split and rename files >> * cleanup and rebase >> >> Signed-off-by: Mickaël Salaün >> Cc: Alexei Starovoitov >> Cc: Andy Lutomirski >> Cc: Daniel Borkmann >> Cc: David S. Miller >> Cc: James Morris >> Cc: Kees Cook >> Cc: Serge E. Hallyn >> Cc: Shuah Khan >> Cc: Will Drewry >> --- >> tools/testing/selftests/Makefile | 1 + >> tools/testing/selftests/bpf/test_verifier.c | 64 +++++ >> tools/testing/selftests/landlock/.gitignore | 4 + >> tools/testing/selftests/landlock/Makefile | 47 ++++ >> tools/testing/selftests/landlock/rules/Makefile | 52 ++++ >> tools/testing/selftests/landlock/rules/README.rst | 1 + >> .../testing/selftests/landlock/rules/bpf_helpers.h | 1 + >> .../testing/selftests/landlock/rules/fs_no_open.c | 31 +++ >> .../selftests/landlock/rules/fs_read_only.c | 31 +++ >> tools/testing/selftests/landlock/test.h | 35 +++ >> tools/testing/selftests/landlock/test_base.c | 31 +++ >> tools/testing/selftests/landlock/test_fs.c | 305 +++++++++++++++++++++ >> tools/testing/selftests/landlock/test_ptrace.c | 161 +++++++++++ >> 13 files changed, 764 insertions(+) >> create mode 100644 tools/testing/selftests/landlock/.gitignore >> create mode 100644 tools/testing/selftests/landlock/Makefile >> create mode 100644 tools/testing/selftests/landlock/rules/Makefile >> create mode 120000 tools/testing/selftests/landlock/rules/README.rst >> create mode 120000 tools/testing/selftests/landlock/rules/bpf_helpers.h >> create mode 100644 tools/testing/selftests/landlock/rules/fs_no_open.c >> create mode 100644 tools/testing/selftests/landlock/rules/fs_read_only.c >> create mode 100644 tools/testing/selftests/landlock/test.h >> create mode 100644 tools/testing/selftests/landlock/test_base.c >> create mode 100644 tools/testing/selftests/landlock/test_fs.c >> create mode 100644 tools/testing/selftests/landlock/test_ptrace.c >> >> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile >> index d8593f1251ec..b584ad456428 100644 >> --- a/tools/testing/selftests/Makefile >> +++ b/tools/testing/selftests/Makefile >> @@ -12,6 +12,7 @@ TARGETS += gpio >> TARGETS += intel_pstate >> TARGETS += ipc >> TARGETS += kcmp >> +TARGETS += landlock >> TARGETS += lib >> TARGETS += membarrier >> TARGETS += memfd >> diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c >> index daa87dd7c80e..77255b14871e 100644 >> --- a/tools/testing/selftests/bpf/test_verifier.c >> +++ b/tools/testing/selftests/bpf/test_verifier.c >> @@ -4536,6 +4536,70 @@ static struct bpf_test tests[] = { >> .result = REJECT, >> .has_prog_subtype = true, >> }, >> + { >> + "missing subtype", >> + .insns = { >> + BPF_MOV32_IMM(BPF_REG_0, 0), >> + BPF_EXIT_INSN(), >> + }, >> + .errstr = "", >> + .result = REJECT, >> + .prog_type = BPF_PROG_TYPE_LANDLOCK, >> + }, >> + { >> + "landlock/fs: always accept", >> + .insns = { >> + BPF_MOV32_IMM(BPF_REG_0, 0), >> + BPF_EXIT_INSN(), >> + }, >> + .result = ACCEPT, >> + .prog_type = BPF_PROG_TYPE_LANDLOCK, >> + .has_prog_subtype = true, >> + .prog_subtype = { >> + .landlock_rule = { >> + .version = 1, >> + .event = LANDLOCK_SUBTYPE_EVENT_FS, >> + } >> + }, >> + }, >> + { >> + "landlock/fs: read context", >> + .insns = { >> + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), >> + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_6, >> + offsetof(struct landlock_context, status)), >> + /* test operations on raw values */ >> + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1), >> + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, >> + offsetof(struct landlock_context, arch)), >> + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1), >> + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, >> + offsetof(struct landlock_context, syscall_nr)), >> + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1), >> + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, >> + offsetof(struct landlock_context, syscall_cmd)), >> + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1), >> + BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_6, >> + offsetof(struct landlock_context, event)), >> + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1), >> + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_6, >> + offsetof(struct landlock_context, arg1)), >> + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_6, >> + offsetof(struct landlock_context, arg2)), >> + BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, 1), >> + BPF_MOV32_IMM(BPF_REG_0, 0), >> + BPF_EXIT_INSN(), >> + }, >> + .result = ACCEPT, >> + .prog_type = BPF_PROG_TYPE_LANDLOCK, >> + .has_prog_subtype = true, >> + .prog_subtype = { >> + .landlock_rule = { >> + .version = 1, >> + .event = LANDLOCK_SUBTYPE_EVENT_FS, >> + } >> + }, >> + }, >> }; >> >> static int probe_filter_length(const struct bpf_insn *fp) >> diff --git a/tools/testing/selftests/landlock/.gitignore b/tools/testing/selftests/landlock/.gitignore >> new file mode 100644 >> index 000000000000..25b9cd834c3c >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/.gitignore >> @@ -0,0 +1,4 @@ >> +/test_base >> +/test_fs >> +/test_ptrace >> +/tmp_* >> diff --git a/tools/testing/selftests/landlock/Makefile b/tools/testing/selftests/landlock/Makefile >> new file mode 100644 >> index 000000000000..9a52c82d64fa >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/Makefile >> @@ -0,0 +1,47 @@ >> +LIBDIR := ../../../lib >> +BPFOBJ := $(LIBDIR)/bpf/bpf.o >> +LOADOBJ := ../../../../samples/bpf/bpf_load.o > > Is the selftest tarball creation tool okay with this? IIRC, it should > be fine since it'll be a built object already, but it's a random > thought I had while looking at this. Hum, I'll check since it's the same for BPF tests. > >> + >> +CFLAGS += -Wl,-no-as-needed -Wall -O2 -I../../../include/uapi -I$(LIBDIR) >> +LDFLAGS += -lelf >> + >> +test_src = $(wildcard test_*.c) >> +rule_src = $(wildcard rules/*.c) >> + >> +test_objs := $(test_src:.c=) >> +rule_objs := $(rule_src:.c=.o) >> + >> +TEST_PROGS := $(test_objs) >> + >> +.PHONY: all clean clean_tmp force >> + >> +all: $(test_objs) $(rule_objs) >> + >> +# force a rebuild of BPFOBJ when its dependencies are updated >> +force: >> + >> +$(BPFOBJ): force >> + $(MAKE) -C $(dir $(BPFOBJ)) >> + >> +$(LOADOBJ): >> + $(MAKE) -C $(dir $(LOADOBJ)) >> + >> +# minimize builds >> +rules/modules.order: $(rule_src) >> + $(MAKE) -C rules >> + @touch $@ >> + >> +$(rule_objs): rules/modules.order >> + @ >> + >> +$(test_objs): $(BPFOBJ) $(LOADOBJ) >> + >> +include ../lib.mk >> + >> +clean_tmp: >> + $(RM) -r tmp_* >> + >> +clean: clean_tmp >> + $(MAKE) -C rules clean >> + $(RM) $(test_objs) >> + >> diff --git a/tools/testing/selftests/landlock/rules/Makefile b/tools/testing/selftests/landlock/rules/Makefile >> new file mode 100644 >> index 000000000000..8d6ff960ff7c >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/rules/Makefile >> @@ -0,0 +1,52 @@ >> +# kbuild trick to avoid linker error. Can be omitted if a module is built. >> +obj- := dummy.o >> + >> +# Tell kbuild to always build the programs >> +always := fs_read_only.o >> +always += fs_no_open.o >> + >> +EXTRA_CFLAGS = -Wall -Wextra >> + >> +# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline: >> +# make samples/bpf/ LLC=~/git/llvm/build/bin/llc CLANG=~/git/llvm/build/bin/clang >> +LLC ?= llc >> +CLANG ?= clang >> + >> +# Verify LLVM compiler tools are available and bpf target is supported by llc >> +.PHONY: all clean verify_cmds verify_target_bpf $(CLANG) $(LLC) >> + >> +# Trick to allow make to be run from this directory >> +all: >> + $(MAKE) -C ../../../../../ $(CURDIR)/ >> + >> +clean: >> + $(MAKE) -C ../../../../../ M=$(CURDIR) clean > > Is this really needed? Others don't have it, I think. This is copied from the BPF tests and yes it's needed. > >> +verify_cmds: $(CLANG) $(LLC) >> + @for TOOL in $^ ; do \ >> + if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \ >> + echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\ >> + exit 1; \ >> + else true; fi; \ >> + done >> + >> +verify_target_bpf: verify_cmds >> + @if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \ >> + echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\ >> + echo " NOTICE: LLVM version >= 3.7.1 required" ;\ >> + exit 2; \ >> + else true; fi >> + >> +%_kern.c: verify_target_bpf >> + >> +# asm/sysreg.h - inline assembly used by it is incompatible with llvm. >> +# But, there is no easy way to fix it, so just exclude it since it is >> +# useless for BPF samples. >> +$(obj)/%.o: $(src)/%.c >> + $(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \ >> + -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \ >> + -Wno-compare-distinct-pointer-types \ >> + -Wno-gnu-variable-sized-type-not-at-end \ >> + -Wno-tautological-compare \ >> + -O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@ > > Is clang required for the samples and the selftests? That needs to be > avoided... there needs to be a way to show people how to build a > landlock rule without requiring clang. I can rewrite this tests without requiring clang but it is already required for BPF tests… > >> + >> diff --git a/tools/testing/selftests/landlock/rules/README.rst b/tools/testing/selftests/landlock/rules/README.rst >> new file mode 120000 >> index 000000000000..605f48aa6f72 >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/rules/README.rst >> @@ -0,0 +1 @@ >> +../../../../../samples/bpf/README.rst >> \ No newline at end of file >> diff --git a/tools/testing/selftests/landlock/rules/bpf_helpers.h b/tools/testing/selftests/landlock/rules/bpf_helpers.h >> new file mode 120000 >> index 000000000000..0aa1a521b39a >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/rules/bpf_helpers.h >> @@ -0,0 +1 @@ >> +../../../../../samples/bpf/bpf_helpers.h >> \ No newline at end of file >> diff --git a/tools/testing/selftests/landlock/rules/fs_no_open.c b/tools/testing/selftests/landlock/rules/fs_no_open.c >> new file mode 100644 >> index 000000000000..c6ea305e58a7 >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/rules/fs_no_open.c >> @@ -0,0 +1,31 @@ >> +/* >> + * Landlock rule - no-open filesystem >> + * >> + * Copyright © 2017 Mickaël Salaün >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2, as >> + * published by the Free Software Foundation. >> + */ >> + >> +#include >> +#include "bpf_helpers.h" >> + >> +SEC("landlock1") >> +static int landlock_fs_prog1(struct landlock_context *ctx) >> +{ >> + if (!(ctx->arg2 & LANDLOCK_ACTION_FS_GET)) >> + return 0; >> + return 1; >> +} >> + >> +SEC("subtype") >> +static union bpf_prog_subtype _subtype = { >> + .landlock_rule = { >> + .version = 1, >> + .event = LANDLOCK_SUBTYPE_EVENT_FS, >> + } >> +}; >> + >> +SEC("license") >> +static const char _license[] = "GPL"; >> diff --git a/tools/testing/selftests/landlock/rules/fs_read_only.c b/tools/testing/selftests/landlock/rules/fs_read_only.c >> new file mode 100644 >> index 000000000000..212dda7c0c27 >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/rules/fs_read_only.c >> @@ -0,0 +1,31 @@ >> +/* >> + * Landlock rule - read-only filesystem >> + * >> + * Copyright © 2017 Mickaël Salaün >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2, as >> + * published by the Free Software Foundation. >> + */ >> + >> +#include >> +#include "bpf_helpers.h" >> + >> +SEC("landlock1") >> +static int landlock_fs_prog1(struct landlock_context *ctx) >> +{ >> + if (!(ctx->arg2 & LANDLOCK_ACTION_FS_WRITE)) >> + return 0; >> + return 1; >> +} >> + >> +SEC("subtype") >> +static union bpf_prog_subtype _subtype = { >> + .landlock_rule = { >> + .version = 1, >> + .event = LANDLOCK_SUBTYPE_EVENT_FS, >> + } >> +}; >> + >> +SEC("license") >> +static const char _license[] = "GPL"; >> diff --git a/tools/testing/selftests/landlock/test.h b/tools/testing/selftests/landlock/test.h >> new file mode 100644 >> index 000000000000..7a194815391b >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/test.h >> @@ -0,0 +1,35 @@ >> +/* >> + * Landlock helpers >> + * >> + * Copyright © 2017 Mickaël Salaün >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2, as >> + * published by the Free Software Foundation. >> + */ >> + >> +#include >> +#include >> +#include >> + >> +#include "../seccomp/test_harness.h" >> +#include "../../../../samples/bpf/bpf_load.h" >> + >> +#ifndef SECCOMP_APPEND_LANDLOCK_RULE >> +#define SECCOMP_APPEND_LANDLOCK_RULE 2 >> +#endif >> + >> +#ifndef seccomp >> +static int seccomp(unsigned int op, unsigned int flags, void *args) >> +{ >> + errno = 0; >> + return syscall(__NR_seccomp, op, flags, args); >> +} >> +#endif >> + >> +#define ASSERT_STEP(cond) \ >> + { \ >> + step--; \ >> + if (!(cond)) \ >> + _exit(step); \ >> + } > > Can you explain this in more detail? I'm assuming there is a problem > with writing to the TH_LOG_STREAM fd or something? It's a trick to use the test framework without requiring to be allowed to write to an FD (i.e. log stream), but only to exit a code. I use this to test a Landlock rule which forbid access to any FS objects (including open FD). This could be used for seccomp too. > >> diff --git a/tools/testing/selftests/landlock/test_base.c b/tools/testing/selftests/landlock/test_base.c >> new file mode 100644 >> index 000000000000..bdf056edee03 >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/test_base.c >> @@ -0,0 +1,31 @@ >> +/* >> + * Landlock tests - base >> + * >> + * Copyright © 2017 Mickaël Salaün >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2, as >> + * published by the Free Software Foundation. >> + */ >> + >> +#define _GNU_SOURCE >> +#include >> + >> +#include "test.h" >> + >> +TEST(seccomp_landlock) >> +{ >> + int 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_APPEND_LANDLOCK_RULE, 0, NULL); >> + EXPECT_EQ(-1, ret); >> + EXPECT_EQ(EFAULT, errno) { >> + TH_LOG("Kernel does not support CONFIG_SECURITY_LANDLOCK"); >> + } >> +} >> + >> +TEST_HARNESS_MAIN >> diff --git a/tools/testing/selftests/landlock/test_fs.c b/tools/testing/selftests/landlock/test_fs.c >> new file mode 100644 >> index 000000000000..e69eda433716 >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/test_fs.c >> @@ -0,0 +1,305 @@ >> +/* >> + * Landlock tests - filesystem >> + * >> + * Copyright © 2017 Mickaël Salaün >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2, as >> + * published by the Free Software Foundation. >> + */ >> + >> +#define _GNU_SOURCE >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +#include /* open() */ >> +#include >> +#include /* mkdir() */ >> +#include /* mmap() */ >> + >> +#include "test.h" >> + >> +#define TMP_PREFIX "tmp_" >> + >> +struct layout1 { >> + int file_ro; >> + int file_rw; >> + int file_wo; >> +}; >> + >> +static void setup_layout1(struct __test_metadata *_metadata, >> + struct layout1 *l1) >> +{ >> + int fd; >> + char buf[] = "fs_read_only"; >> + >> + l1->file_ro = -1; >> + l1->file_rw = -1; >> + l1->file_wo = -1; >> + >> + fd = open(TMP_PREFIX "file_created", >> + O_CREAT | O_EXCL | O_WRONLY | O_CLOEXEC, 0600); >> + ASSERT_GE(fd, 0); >> + ASSERT_EQ(sizeof(buf), write(fd, buf, sizeof(buf))); >> + ASSERT_EQ(0, close(fd)); >> + >> + fd = mkdir(TMP_PREFIX "dir_created", 0600); >> + ASSERT_GE(fd, 0); >> + ASSERT_EQ(0, close(fd)); >> + >> + l1->file_ro = open(TMP_PREFIX "file_ro", >> + O_CREAT | O_EXCL | O_WRONLY | O_CLOEXEC, 0600); >> + ASSERT_LE(0, l1->file_ro); >> + ASSERT_EQ(sizeof(buf), write(l1->file_ro, buf, sizeof(buf))); >> + ASSERT_EQ(0, close(l1->file_ro)); >> + l1->file_ro = open(TMP_PREFIX "file_ro", >> + O_RDONLY | O_CLOEXEC, 0600); >> + ASSERT_LE(0, l1->file_ro); >> + >> + l1->file_rw = open(TMP_PREFIX "file_rw", >> + O_CREAT | O_EXCL | O_RDWR | O_CLOEXEC, 0600); >> + ASSERT_LE(0, l1->file_rw); >> + ASSERT_EQ(sizeof(buf), write(l1->file_rw, buf, sizeof(buf))); >> + ASSERT_EQ(0, lseek(l1->file_rw, 0, SEEK_SET)); >> + >> + l1->file_wo = open(TMP_PREFIX "file_wo", >> + O_CREAT | O_EXCL | O_WRONLY | O_CLOEXEC, 0600); >> + ASSERT_LE(0, l1->file_wo); >> + ASSERT_EQ(sizeof(buf), write(l1->file_wo, buf, sizeof(buf))); >> + ASSERT_EQ(0, lseek(l1->file_wo, 0, SEEK_SET)); >> +} >> + >> +static void cleanup_layout1(void) >> +{ >> + unlink(TMP_PREFIX "file_created"); >> + unlink(TMP_PREFIX "file_ro"); >> + unlink(TMP_PREFIX "file_rw"); >> + unlink(TMP_PREFIX "file_wo"); >> + unlink(TMP_PREFIX "should_not_exist"); >> + rmdir(TMP_PREFIX "dir_created"); >> +} >> + >> +FIXTURE(fs_read_only) { >> + struct layout1 l1; >> + int prog; >> +}; >> + >> +FIXTURE_SETUP(fs_read_only) >> +{ >> + cleanup_layout1(); >> + setup_layout1(_metadata, &self->l1); >> + >> + ASSERT_EQ(0, load_bpf_file("rules/fs_read_only.o")) { >> + TH_LOG("%s", bpf_log_buf); >> + } >> + self->prog = prog_fd[0]; >> + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0)) { >> + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS"); >> + } >> +} >> + >> +FIXTURE_TEARDOWN(fs_read_only) >> +{ >> + EXPECT_EQ(0, close(self->prog)); >> + /* cleanup_layout1() would be denied here */ >> +} >> + >> +TEST_F(fs_read_only, load_prog) {} >> + >> +TEST_F(fs_read_only, read_only_file) >> +{ >> + int fd; >> + int step = 0; >> + char buf_write[] = "should not be written"; >> + char buf_read[2]; >> + >> + ASSERT_EQ(-1, write(self->l1.file_ro, buf_write, sizeof(buf_write))); >> + ASSERT_EQ(EBADF, errno); >> + >> + ASSERT_EQ(-1, read(self->l1.file_wo, buf_read, sizeof(buf_read))); >> + ASSERT_EQ(EBADF, errno); >> + >> + ASSERT_EQ(0, seccomp(SECCOMP_APPEND_LANDLOCK_RULE, 0, &self->prog)) { >> + TH_LOG("Failed to apply rule fs_read_only: %s", >> + strerror(errno)); >> + } >> + >> + fd = open(".", O_TMPFILE | O_EXCL | O_RDWR | O_CLOEXEC, 0600); >> + ASSERT_STEP(fd == -1); >> + ASSERT_STEP(errno != EOPNOTSUPP) >> + ASSERT_STEP(errno == EPERM); >> + >> + fd = open(TMP_PREFIX "file_created", >> + O_RDONLY | O_CLOEXEC); >> + ASSERT_STEP(fd >= 0); >> + ASSERT_STEP(!close(fd)); >> + >> + fd = open(TMP_PREFIX "file_created", >> + O_RDWR | O_CLOEXEC); >> + ASSERT_STEP(fd == -1); >> + ASSERT_STEP(errno == EPERM); >> + >> + fd = open(TMP_PREFIX "file_created", >> + O_WRONLY | O_CLOEXEC); >> + ASSERT_STEP(fd == -1); >> + ASSERT_STEP(errno == EPERM); >> + >> + fd = open(TMP_PREFIX "should_not_exist", >> + O_CREAT | O_EXCL | O_CLOEXEC, 0600); >> + ASSERT_STEP(fd == -1); >> + ASSERT_STEP(errno == EPERM); >> + >> + ASSERT_STEP(-1 == >> + write(self->l1.file_ro, buf_write, sizeof(buf_write))); >> + ASSERT_STEP(errno == EBADF); >> + ASSERT_STEP(sizeof(buf_read) == >> + read(self->l1.file_ro, buf_read, sizeof(buf_read))); >> + >> + ASSERT_STEP(-1 == >> + write(self->l1.file_rw, buf_write, sizeof(buf_write))); >> + ASSERT_STEP(errno == EPERM); >> + ASSERT_STEP(sizeof(buf_read) == >> + read(self->l1.file_rw, buf_read, sizeof(buf_read))); >> + >> + ASSERT_STEP(-1 == write(self->l1.file_wo, buf_write, sizeof(buf_write))); >> + ASSERT_STEP(errno == EPERM); >> + ASSERT_STEP(-1 == read(self->l1.file_wo, buf_read, sizeof(buf_read))); >> + ASSERT_STEP(errno == EBADF); >> + >> + ASSERT_STEP(-1 == unlink(TMP_PREFIX "file_created")); >> + ASSERT_STEP(errno == EPERM); >> + ASSERT_STEP(-1 == rmdir(TMP_PREFIX "dir_created")); >> + ASSERT_STEP(errno == EPERM); >> + >> + ASSERT_STEP(0 == close(self->l1.file_ro)); >> + ASSERT_STEP(0 == close(self->l1.file_rw)); >> + ASSERT_STEP(0 == close(self->l1.file_wo)); >> +} >> + >> +TEST_F(fs_read_only, read_only_mount) >> +{ >> + int step = 0; >> + >> + ASSERT_EQ(0, mount(".", TMP_PREFIX "dir_created", >> + NULL, MS_BIND, NULL)); >> + ASSERT_EQ(0, umount2(TMP_PREFIX "dir_created", MNT_FORCE)); >> + >> + ASSERT_EQ(0, seccomp(SECCOMP_APPEND_LANDLOCK_RULE, 0, &self->prog)) { >> + TH_LOG("Failed to apply rule fs_read_only: %s", >> + strerror(errno)); >> + } >> + >> + ASSERT_STEP(-1 == mount(".", TMP_PREFIX "dir_created", >> + NULL, MS_BIND, NULL)); >> + ASSERT_STEP(errno == EPERM); >> + ASSERT_STEP(-1 == umount("/")); >> + ASSERT_STEP(errno == EPERM); >> +} >> + >> +TEST_F(fs_read_only, read_only_mem) >> +{ >> + int step = 0; >> + void *addr; >> + >> + addr = mmap(NULL, 1, PROT_READ | PROT_WRITE, >> + MAP_SHARED, self->l1.file_rw, 0); >> + ASSERT_NE(NULL, addr); >> + ASSERT_EQ(0, munmap(addr, 1)); >> + >> + ASSERT_EQ(0, seccomp(SECCOMP_APPEND_LANDLOCK_RULE, 0, &self->prog)) { >> + TH_LOG("Failed to apply rule fs_read_only: %s", >> + strerror(errno)); >> + } >> + >> + addr = mmap(NULL, 1, PROT_READ, MAP_SHARED, >> + self->l1.file_rw, 0); >> + ASSERT_STEP(addr != NULL); >> + ASSERT_STEP(-1 == mprotect(addr, 1, PROT_WRITE)); >> + ASSERT_STEP(errno == EPERM); >> + ASSERT_STEP(0 == munmap(addr, 1)); >> + >> + addr = mmap(NULL, 1, PROT_READ | PROT_WRITE, MAP_SHARED, >> + self->l1.file_rw, 0); >> + ASSERT_STEP(addr != NULL); >> + ASSERT_STEP(errno == EPERM); >> + >> + addr = mmap(NULL, 1, PROT_READ | PROT_WRITE, MAP_PRIVATE, >> + self->l1.file_rw, 0); >> + ASSERT_STEP(addr != NULL); >> + ASSERT_STEP(0 == munmap(addr, 1)); >> +} >> + >> +FIXTURE(fs_no_open) { >> + struct layout1 l1; >> + int prog; >> +}; >> + >> +FIXTURE_SETUP(fs_no_open) >> +{ >> + cleanup_layout1(); >> + setup_layout1(_metadata, &self->l1); >> + >> + ASSERT_EQ(0, load_bpf_file("rules/fs_no_open.o")) { >> + TH_LOG("%s", bpf_log_buf); >> + } >> + self->prog = prog_fd[0]; >> + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0)) { >> + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS"); >> + } >> +} >> + >> +FIXTURE_TEARDOWN(fs_no_open) >> +{ >> + EXPECT_EQ(0, close(self->prog)); >> + cleanup_layout1(); >> +} >> + >> +static void landlocked_deny_open(struct __test_metadata *_metadata, >> + struct layout1 *l1) >> +{ >> + int fd; >> + void *addr; >> + >> + fd = open(".", O_DIRECTORY | O_CLOEXEC); >> + ASSERT_EQ(-1, fd); >> + ASSERT_EQ(EPERM, errno); >> + >> + addr = mmap(NULL, 1, PROT_READ | PROT_WRITE, >> + MAP_SHARED, l1->file_rw, 0); >> + ASSERT_NE(NULL, addr); >> + ASSERT_EQ(0, munmap(addr, 1)); >> +} >> + >> +TEST_F(fs_no_open, deny_open_for_hierarchy) { >> + int fd; >> + int status; >> + pid_t child; >> + >> + fd = open(".", O_DIRECTORY | O_CLOEXEC); >> + ASSERT_LE(0, fd); >> + ASSERT_EQ(0, close(fd)); >> + >> + ASSERT_EQ(0, seccomp(SECCOMP_APPEND_LANDLOCK_RULE, 0, &self->prog)) { >> + TH_LOG("Failed to apply rule fs_no_open: %s", strerror(errno)); >> + } >> + >> + landlocked_deny_open(_metadata, &self->l1); >> + >> + child = fork(); >> + ASSERT_LE(0, child); >> + if (!child) { >> + landlocked_deny_open(_metadata, &self->l1); >> + _exit(1); >> + } >> + ASSERT_EQ(child, waitpid(child, &status, 0)); >> + ASSERT_TRUE(WIFEXITED(status)); >> + _exit(WEXITSTATUS(status)); >> +} >> + >> +TEST_HARNESS_MAIN >> diff --git a/tools/testing/selftests/landlock/test_ptrace.c b/tools/testing/selftests/landlock/test_ptrace.c >> new file mode 100644 >> index 000000000000..0c940a7fd3d0 >> --- /dev/null >> +++ b/tools/testing/selftests/landlock/test_ptrace.c >> @@ -0,0 +1,161 @@ >> +/* >> + * Landlock tests - ptrace >> + * >> + * Copyright © 2017 Mickaël Salaün >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2, as >> + * published by the Free Software Foundation. >> + */ >> + >> +#define _GNU_SOURCE >> +#include /* raise */ >> +#include >> +#include /* waitpid */ >> +#include /* waitpid */ >> +#include /* fork, pipe */ >> + >> +#include "test.h" >> + >> +static void apply_null_sandbox(struct __test_metadata *_metadata) >> +{ >> + const struct bpf_insn prog_accept[] = { >> + BPF_MOV32_IMM(BPF_REG_0, 0), >> + BPF_EXIT_INSN(), >> + }; >> + const union bpf_prog_subtype subtype = { >> + .landlock_rule = { >> + .version = 1, >> + .event = LANDLOCK_SUBTYPE_EVENT_FS, >> + } >> + }; >> + int prog; >> + char log[256] = ""; >> + >> + prog = bpf_load_program(BPF_PROG_TYPE_LANDLOCK, >> + (const struct bpf_insn *)&prog_accept, >> + sizeof(prog_accept) / sizeof(struct bpf_insn), "GPL", >> + 0, log, sizeof(log), &subtype); >> + ASSERT_NE(-1, prog) { >> + TH_LOG("Failed to load minimal rule: %s\n%s", >> + strerror(errno), log); >> + } >> + ASSERT_EQ(0, prctl(PR_SET_NO_NEW_PRIVS, 1, NULL, 0, 0)) { >> + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS"); >> + } >> + ASSERT_EQ(0, seccomp(SECCOMP_APPEND_LANDLOCK_RULE, 0, &prog)) { >> + TH_LOG("Failed to apply minimal rule: %s", strerror(errno)); >> + } >> + EXPECT_EQ(0, close(prog)); >> +} >> + >> +/* PTRACE_TRACEME and PTRACE_ATTACH without Landlock rules effect */ >> +static void check_ptrace(struct __test_metadata *_metadata, >> + int sandbox_both, int sandbox_parent, int sandbox_child, >> + int expect_ptrace) >> +{ >> + pid_t child; >> + int status; >> + int pipefd[2]; >> + >> + ASSERT_EQ(0, pipe(pipefd)); >> + if (sandbox_both) >> + apply_null_sandbox(_metadata); >> + >> + child = fork(); >> + ASSERT_LE(0, child); >> + if (child == 0) { >> + char buf; >> + >> + EXPECT_EQ(0, close(pipefd[1])); >> + if (sandbox_child) >> + apply_null_sandbox(_metadata); >> + >> + /* test traceme */ >> + ASSERT_EQ(expect_ptrace, ptrace(PTRACE_TRACEME)); >> + if (expect_ptrace) { >> + ASSERT_EQ(EPERM, errno); >> + } else { >> + ASSERT_EQ(0, raise(SIGSTOP)); >> + } >> + >> + /* sync */ >> + ASSERT_EQ(1, read(pipefd[0], &buf, 1)) { >> + TH_LOG("Failed to read() sync from parent"); >> + } >> + ASSERT_EQ('.', buf); >> + _exit(_metadata->passed ? EXIT_SUCCESS : EXIT_FAILURE); >> + } >> + >> + EXPECT_EQ(0, close(pipefd[0])); >> + if (sandbox_parent) >> + apply_null_sandbox(_metadata); >> + >> + /* test traceme */ >> + if (!expect_ptrace) { >> + ASSERT_EQ(child, waitpid(child, &status, 0)); >> + ASSERT_EQ(1, WIFSTOPPED(status)); >> + ASSERT_EQ(0, ptrace(PTRACE_DETACH, child, NULL, 0)); >> + } >> + /* test attach */ >> + ASSERT_EQ(expect_ptrace, ptrace(PTRACE_ATTACH, child, NULL, 0)); >> + if (expect_ptrace) { >> + ASSERT_EQ(EPERM, errno); >> + } else { >> + ASSERT_EQ(child, waitpid(child, &status, 0)); >> + ASSERT_EQ(1, WIFSTOPPED(status)); >> + ASSERT_EQ(0, ptrace(PTRACE_CONT, child, NULL, 0)); >> + } >> + >> + /* sync */ >> + ASSERT_EQ(1, write(pipefd[1], ".", 1)) { >> + TH_LOG("Failed to write() sync to child"); >> + } >> + ASSERT_EQ(child, waitpid(child, &status, 0)); >> + if (WIFSIGNALED(status) || WEXITSTATUS(status)) >> + _metadata->passed = 0; >> +} >> + >> +TEST(ptrace_allow_without_sandbox) >> +{ >> + /* no sandbox */ >> + check_ptrace(_metadata, 0, 0, 0, 0); >> +} >> + >> +TEST(ptrace_allow_with_one_sandbox) >> +{ >> + /* child sandbox */ >> + check_ptrace(_metadata, 0, 0, 1, 0); >> +} >> + >> +TEST(ptrace_allow_with_nested_sandbox) >> +{ >> + /* inherited and child sandbox */ >> + check_ptrace(_metadata, 1, 0, 1, 0); >> +} >> + >> +TEST(ptrace_deny_with_parent_sandbox) >> +{ >> + /* parent sandbox */ >> + check_ptrace(_metadata, 0, 1, 0, -1); >> +} >> + >> +TEST(ptrace_deny_with_nested_and_parent_sandbox) >> +{ >> + /* inherited and parent sandbox */ >> + check_ptrace(_metadata, 1, 1, 0, -1); >> +} >> + >> +TEST(ptrace_deny_with_forked_sandbox) >> +{ >> + /* inherited, parent and child sandbox */ >> + check_ptrace(_metadata, 1, 1, 1, -1); >> +} >> + >> +TEST(ptrace_deny_with_sibling_sandbox) >> +{ >> + /* parent and child sandbox */ >> + check_ptrace(_metadata, 0, 1, 1, -1); >> +} >> + >> +TEST_HARNESS_MAIN >> -- >> 2.11.0 >> > > Awesome. I love to see all these tests, with both positive and > negative checks. Nice! > > -Kees >