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-rw-r--r--test/syscalls/linux/BUILD2
-rw-r--r--test/syscalls/linux/proc_pid_uid_gid_map.cc155
2 files changed, 124 insertions, 33 deletions
diff --git a/test/syscalls/linux/BUILD b/test/syscalls/linux/BUILD
index 7dd63dd0a..1e386193b 100644
--- a/test/syscalls/linux/BUILD
+++ b/test/syscalls/linux/BUILD
@@ -1455,6 +1455,8 @@ cc_binary(
linkstatic = 1,
deps = [
"//test/util:capability_util",
+ "//test/util:cleanup",
+ "//test/util:file_descriptor",
"//test/util:fs_util",
"//test/util:logging",
"//test/util:multiprocess_util",
diff --git a/test/syscalls/linux/proc_pid_uid_gid_map.cc b/test/syscalls/linux/proc_pid_uid_gid_map.cc
index e6a5265fa..e782f2318 100644
--- a/test/syscalls/linux/proc_pid_uid_gid_map.cc
+++ b/test/syscalls/linux/proc_pid_uid_gid_map.cc
@@ -20,12 +20,17 @@
#include <functional>
#include <string>
+#include <tuple>
+#include <utility>
#include <vector>
#include "gtest/gtest.h"
+#include "absl/strings/ascii.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/str_split.h"
#include "test/util/capability_util.h"
+#include "test/util/cleanup.h"
+#include "test/util/file_descriptor.h"
#include "test/util/fs_util.h"
#include "test/util/logging.h"
#include "test/util/multiprocess_util.h"
@@ -44,10 +49,53 @@ PosixErrorOr<int> InNewUserNamespace(const std::function<void()>& fn) {
});
}
+PosixErrorOr<std::tuple<pid_t, Cleanup>> CreateProcessInNewUserNamespace() {
+ int pipefd[2];
+ if (pipe(pipefd) < 0) {
+ return PosixError(errno, "pipe failed");
+ }
+ const auto cleanup_pipe_read =
+ Cleanup([&] { EXPECT_THAT(close(pipefd[0]), SyscallSucceeds()); });
+ auto cleanup_pipe_write =
+ Cleanup([&] { EXPECT_THAT(close(pipefd[1]), SyscallSucceeds()); });
+ pid_t child_pid = fork();
+ if (child_pid < 0) {
+ return PosixError(errno, "fork failed");
+ }
+ if (child_pid == 0) {
+ // Close our copy of the pipe's read end, which doesn't really matter.
+ TEST_PCHECK(close(pipefd[0]) >= 0);
+ TEST_PCHECK(unshare(CLONE_NEWUSER) == 0);
+ MaybeSave();
+ // Indicate that we've switched namespaces by unblocking the parent's read.
+ TEST_PCHECK(close(pipefd[1]) >= 0);
+ while (true) {
+ SleepSafe(absl::Minutes(1));
+ }
+ }
+ auto cleanup_child = Cleanup([child_pid] {
+ EXPECT_THAT(kill(child_pid, SIGKILL), SyscallSucceeds());
+ int status;
+ ASSERT_THAT(RetryEINTR(waitpid)(child_pid, &status, 0),
+ SyscallSucceedsWithValue(child_pid));
+ EXPECT_TRUE(WIFSIGNALED(status) && WTERMSIG(status) == SIGKILL)
+ << "status = " << status;
+ });
+ // Close our copy of the pipe's write end, then wait for the child to close
+ // its copy, indicating that it's switched namespaces.
+ cleanup_pipe_write.Release()();
+ char buf;
+ if (RetryEINTR(read)(pipefd[0], &buf, 1) < 0) {
+ return PosixError(errno, "reading from pipe failed");
+ }
+ MaybeSave();
+ return std::make_tuple(child_pid, std::move(cleanup_child));
+}
+
// TEST_CHECK-fails on error, since this function is used in contexts that
// require async-signal-safety.
-void DenySelfSetgroups() {
- int fd = open("/proc/self/setgroups", O_WRONLY);
+void DenySetgroupsByPath(const char* path) {
+ int fd = open(path, O_WRONLY);
if (fd < 0 && errno == ENOENT) {
// On kernels where this file doesn't exist, writing "deny" to it isn't
// necessary to write to gid_map.
@@ -61,13 +109,19 @@ void DenySelfSetgroups() {
TEST_PCHECK(close(fd) == 0);
}
+void DenySelfSetgroups() { DenySetgroupsByPath("/proc/self/setgroups"); }
+
+void DenyPidSetgroups(pid_t pid) {
+ DenySetgroupsByPath(absl::StrCat("/proc/", pid, "/setgroups").c_str());
+}
+
// Returns a valid UID/GID that isn't id.
uint32_t another_id(uint32_t id) { return (id + 1) % 65535; }
struct TestParam {
std::string desc;
- std::string map_filename;
int cap;
+ std::function<std::string(absl::string_view)> get_map_filename;
std::function<uint32_t()> get_current_id;
};
@@ -75,11 +129,29 @@ std::string DescribeTestParam(const ::testing::TestParamInfo<TestParam>& info) {
return info.param.desc;
}
-class ProcSelfUidGidMapTest : public ::testing::TestWithParam<TestParam> {
+std::vector<TestParam> UidGidMapTestParams() {
+ return {TestParam{"UID", CAP_SETUID,
+ [](absl::string_view pid) {
+ return absl::StrCat("/proc/", pid, "/uid_map");
+ },
+ []() -> uint32_t { return getuid(); }},
+ TestParam{"GID", CAP_SETGID,
+ [](absl::string_view pid) {
+ return absl::StrCat("/proc/", pid, "/gid_map");
+ },
+ []() -> uint32_t { return getgid(); }}};
+}
+
+class ProcUidGidMapTest : public ::testing::TestWithParam<TestParam> {
+ protected:
+ uint32_t CurrentID() { return GetParam().get_current_id(); }
+};
+
+class ProcSelfUidGidMapTest : public ProcUidGidMapTest {
protected:
PosixErrorOr<int> InNewUserNamespaceWithMapFD(
const std::function<void(int)>& fn) {
- std::string map_filename = GetParam().map_filename;
+ std::string map_filename = GetParam().get_map_filename("self");
return InNewUserNamespace([&] {
int fd = open(map_filename.c_str(), O_RDWR);
TEST_PCHECK(fd >= 0);
@@ -88,9 +160,10 @@ class ProcSelfUidGidMapTest : public ::testing::TestWithParam<TestParam> {
TEST_PCHECK(close(fd) == 0);
});
}
+};
- uint32_t CurrentID() { return GetParam().get_current_id(); }
-
+class ProcPidUidGidMapTest : public ProcUidGidMapTest {
+ protected:
PosixErrorOr<bool> HaveSetIDCapability() {
return HaveCapability(GetParam().cap);
}
@@ -100,11 +173,17 @@ class ProcSelfUidGidMapTest : public ::testing::TestWithParam<TestParam> {
// IDs into a child user namespace, since even with CAP_SET*ID this is only
// possible if those IDs are mapped into the current one.
PosixErrorOr<bool> AllIDsMapped() {
- ASSIGN_OR_RETURN_ERRNO(std::string id_map, GetContents(GetParam().map_filename));
+ ASSIGN_OR_RETURN_ERRNO(std::string id_map,
+ GetContents(GetParam().get_map_filename("self")));
+ absl::StripTrailingAsciiWhitespace(&id_map);
std::vector<std::string> id_map_parts =
absl::StrSplit(id_map, ' ', absl::SkipEmpty());
return id_map_parts == std::vector<std::string>({"0", "0", "4294967295"});
}
+
+ PosixErrorOr<FileDescriptor> OpenMapFile(pid_t pid) {
+ return Open(GetParam().get_map_filename(absl::StrCat(pid)), O_RDWR);
+ }
};
TEST_P(ProcSelfUidGidMapTest, IsInitiallyEmpty) {
@@ -117,7 +196,6 @@ TEST_P(ProcSelfUidGidMapTest, IsInitiallyEmpty) {
}
TEST_P(ProcSelfUidGidMapTest, IdentityMapOwnID) {
- // This is the only write permitted if the writer does not have CAP_SET*ID.
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(CanCreateUserNamespace()));
uint32_t id = CurrentID();
std::string line = absl::StrCat(id, " ", id, " 1");
@@ -148,7 +226,6 @@ TEST_P(ProcSelfUidGidMapTest, TrailingNewlineAndNULIgnored) {
TEST_P(ProcSelfUidGidMapTest, NonIdentityMapOwnID) {
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(CanCreateUserNamespace()));
- SKIP_IF(ASSERT_NO_ERRNO_AND_VALUE(HaveSetIDCapability()));
uint32_t id = CurrentID();
uint32_t id2 = another_id(id);
std::string line = absl::StrCat(id2, " ", id, " 1");
@@ -160,9 +237,11 @@ TEST_P(ProcSelfUidGidMapTest, NonIdentityMapOwnID) {
IsPosixErrorOkAndHolds(0));
}
-TEST_P(ProcSelfUidGidMapTest, MapOtherIDUnprivileged) {
+TEST_P(ProcSelfUidGidMapTest, MapOtherID) {
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(CanCreateUserNamespace()));
- SKIP_IF(ASSERT_NO_ERRNO_AND_VALUE(HaveSetIDCapability()));
+ // Whether or not we have CAP_SET*ID is irrelevant: the process running in the
+ // new (child) user namespace won't have any capabilities in the current
+ // (parent) user namespace, which is needed.
uint32_t id = CurrentID();
uint32_t id2 = another_id(id);
std::string line = absl::StrCat(id, " ", id2, " 1");
@@ -174,25 +253,41 @@ TEST_P(ProcSelfUidGidMapTest, MapOtherIDUnprivileged) {
IsPosixErrorOkAndHolds(0));
}
-TEST_P(ProcSelfUidGidMapTest, MapOtherIDPrivileged) {
+INSTANTIATE_TEST_CASE_P(All, ProcSelfUidGidMapTest,
+ ::testing::ValuesIn(UidGidMapTestParams()),
+ DescribeTestParam);
+
+TEST_P(ProcPidUidGidMapTest, MapOtherIDPrivileged) {
+ // Like ProcSelfUidGidMapTest_MapOtherID, but since we have CAP_SET*ID in the
+ // parent user namespace (this one), we can map IDs that aren't ours.
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(CanCreateUserNamespace()));
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveSetIDCapability()));
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(AllIDsMapped()));
+
+ pid_t child_pid;
+ Cleanup cleanup_child;
+ std::tie(child_pid, cleanup_child) =
+ ASSERT_NO_ERRNO_AND_VALUE(CreateProcessInNewUserNamespace());
+
uint32_t id = CurrentID();
uint32_t id2 = another_id(id);
std::string line = absl::StrCat(id, " ", id2, " 1");
- EXPECT_THAT(
- InNewUserNamespaceWithMapFD([&](int fd) {
- DenySelfSetgroups();
- TEST_PCHECK(write(fd, line.c_str(), line.size()) == line.size());
- }),
- IsPosixErrorOkAndHolds(0));
+ DenyPidSetgroups(child_pid);
+ auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenMapFile(child_pid));
+ EXPECT_THAT(write(fd.get(), line.c_str(), line.size()),
+ SyscallSucceedsWithValue(line.size()));
}
-TEST_P(ProcSelfUidGidMapTest, MapAnyIDsPrivileged) {
+TEST_P(ProcPidUidGidMapTest, MapAnyIDsPrivileged) {
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(CanCreateUserNamespace()));
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveSetIDCapability()));
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(AllIDsMapped()));
+
+ pid_t child_pid;
+ Cleanup cleanup_child;
+ std::tie(child_pid, cleanup_child) =
+ ASSERT_NO_ERRNO_AND_VALUE(CreateProcessInNewUserNamespace());
+
// Test all of:
//
// - Mapping ranges of length > 1
@@ -201,21 +296,15 @@ TEST_P(ProcSelfUidGidMapTest, MapAnyIDsPrivileged) {
//
// - Non-identity mappings
char entries[] = "2 0 2\n4 6 2";
- EXPECT_THAT(
- InNewUserNamespaceWithMapFD([&](int fd) {
- DenySelfSetgroups();
- TEST_PCHECK(write(fd, entries, sizeof(entries)) == sizeof(entries));
- }),
- IsPosixErrorOkAndHolds(0));
+ DenyPidSetgroups(child_pid);
+ auto fd = ASSERT_NO_ERRNO_AND_VALUE(OpenMapFile(child_pid));
+ EXPECT_THAT(write(fd.get(), entries, sizeof(entries)),
+ SyscallSucceedsWithValue(sizeof(entries)));
}
-INSTANTIATE_TEST_CASE_P(
- All, ProcSelfUidGidMapTest,
- ::testing::Values(TestParam{"UID", "/proc/self/uid_map", CAP_SETUID,
- []() -> uint32_t { return getuid(); }},
- TestParam{"GID", "/proc/self/gid_map", CAP_SETGID,
- []() -> uint32_t { return getgid(); }}),
- DescribeTestParam);
+INSTANTIATE_TEST_CASE_P(All, ProcPidUidGidMapTest,
+ ::testing::ValuesIn(UidGidMapTestParams()),
+ DescribeTestParam);
} // namespace testing
} // namespace gvisor
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 19:57:25 +0000