Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 534 insertions, 0 deletions

diff --git a/tools/testing/selftests/filesystems/binderfs/.gitignore b/tools/testing/selftests/filesystems/binderfs/.gitignore
new file mode 100644
index 000000000..8e5cf9084
--- /dev/null
+++ b/tools/testing/selftests/filesystems/binderfs/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+binderfs_test
diff --git a/tools/testing/selftests/filesystems/binderfs/Makefile b/tools/testing/selftests/filesystems/binderfs/Makefile
new file mode 100644
index 000000000..8af25ae96
--- /dev/null
+++ b/tools/testing/selftests/filesystems/binderfs/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+
+CFLAGS += -I../../../../../usr/include/ -pthread
+TEST_GEN_PROGS := binderfs_test
+
+binderfs_test: binderfs_test.c ../../kselftest.h ../../kselftest_harness.h
+
+include ../../lib.mk
diff --git a/tools/testing/selftests/filesystems/binderfs/binderfs_test.c b/tools/testing/selftests/filesystems/binderfs/binderfs_test.c
new file mode 100644
index 000000000..477cbb042
--- /dev/null
+++ b/tools/testing/selftests/filesystems/binderfs/binderfs_test.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/fsuid.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/sysinfo.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <linux/android/binder.h>
+#include <linux/android/binderfs.h>
+
+#include "../../kselftest_harness.h"
+
+#define DEFAULT_THREADS 4
+
+#define PTR_TO_INT(p) ((int)((intptr_t)(p)))
+#define INT_TO_PTR(u) ((void *)((intptr_t)(u)))
+
+#define close_prot_errno_disarm(fd) \
+	if (fd >= 0) {              \
+		int _e_ = errno;    \
+		close(fd);          \
+		errno = _e_;        \
+		fd = -EBADF;        \
+	}
+
+static void change_mountns(struct __test_metadata *_metadata)
+{
+	int ret;
+
+	ret = unshare(CLONE_NEWNS);
+	ASSERT_EQ(ret, 0) {
+		TH_LOG("%s - Failed to unshare mount namespace",
+			strerror(errno));
+	}
+
+	ret = mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, 0);
+	ASSERT_EQ(ret, 0) {
+		TH_LOG("%s - Failed to mount / as private",
+			strerror(errno));
+	}
+}
+
+static int __do_binderfs_test(struct __test_metadata *_metadata)
+{
+	int fd, ret, saved_errno, result = 1;
+	size_t len;
+	ssize_t wret;
+	struct binderfs_device device = { 0 };
+	struct binder_version version = { 0 };
+	char binderfs_mntpt[] = P_tmpdir "/binderfs_XXXXXX",
+		device_path[sizeof(P_tmpdir "/binderfs_XXXXXX/") + BINDERFS_MAX_NAME];
+
+	change_mountns(_metadata);
+
+	EXPECT_NE(mkdtemp(binderfs_mntpt), NULL) {
+		TH_LOG("%s - Failed to create binderfs mountpoint",
+			strerror(errno));
+		goto out;
+	}
+
+	ret = mount(NULL, binderfs_mntpt, "binder", 0, 0);
+	EXPECT_EQ(ret, 0) {
+		if (errno == ENODEV)
+			SKIP(goto out, "binderfs missing");
+		TH_LOG("%s - Failed to mount binderfs", strerror(errno));
+		goto rmdir;
+	}
+
+	/* success: binderfs mounted */
+
+	memcpy(device.name, "my-binder", strlen("my-binder"));
+
+	snprintf(device_path, sizeof(device_path), "%s/binder-control", binderfs_mntpt);
+	fd = open(device_path, O_RDONLY | O_CLOEXEC);
+	EXPECT_GE(fd, 0) {
+		TH_LOG("%s - Failed to open binder-control device",
+			strerror(errno));
+		goto umount;
+	}
+
+	ret = ioctl(fd, BINDER_CTL_ADD, &device);
+	saved_errno = errno;
+	close(fd);
+	errno = saved_errno;
+	EXPECT_GE(ret, 0) {
+		TH_LOG("%s - Failed to allocate new binder device",
+			strerror(errno));
+		goto umount;
+	}
+
+	TH_LOG("Allocated new binder device with major %d, minor %d, and name %s",
+		device.major, device.minor, device.name);
+
+	/* success: binder device allocation */
+
+	snprintf(device_path, sizeof(device_path), "%s/my-binder", binderfs_mntpt);
+	fd = open(device_path, O_CLOEXEC | O_RDONLY);
+	EXPECT_GE(fd, 0) {
+		TH_LOG("%s - Failed to open my-binder device",
+			strerror(errno));
+		goto umount;
+	}
+
+	ret = ioctl(fd, BINDER_VERSION, &version);
+	saved_errno = errno;
+	close(fd);
+	errno = saved_errno;
+	EXPECT_GE(ret, 0) {
+		TH_LOG("%s - Failed to open perform BINDER_VERSION request",
+			strerror(errno));
+		goto umount;
+	}
+
+	TH_LOG("Detected binder version: %d", version.protocol_version);
+
+	/* success: binder transaction with binderfs binder device */
+
+	ret = unlink(device_path);
+	EXPECT_EQ(ret, 0) {
+		TH_LOG("%s - Failed to delete binder device",
+			strerror(errno));
+		goto umount;
+	}
+
+	/* success: binder device removal */
+
+	snprintf(device_path, sizeof(device_path), "%s/binder-control", binderfs_mntpt);
+	ret = unlink(device_path);
+	EXPECT_NE(ret, 0) {
+		TH_LOG("Managed to delete binder-control device");
+		goto umount;
+	}
+	EXPECT_EQ(errno, EPERM) {
+		TH_LOG("%s - Failed to delete binder-control device but exited with unexpected error code",
+			strerror(errno));
+		goto umount;
+	}
+
+	/* success: binder-control device removal failed as expected */
+	result = 0;
+
+umount:
+	ret = umount2(binderfs_mntpt, MNT_DETACH);
+	EXPECT_EQ(ret, 0) {
+		TH_LOG("%s - Failed to unmount binderfs", strerror(errno));
+	}
+rmdir:
+	ret = rmdir(binderfs_mntpt);
+	EXPECT_EQ(ret, 0) {
+		TH_LOG("%s - Failed to rmdir binderfs mount", strerror(errno));
+	}
+out:
+	return result;
+}
+
+static int wait_for_pid(pid_t pid)
+{
+	int status, ret;
+
+again:
+	ret = waitpid(pid, &status, 0);
+	if (ret == -1) {
+		if (errno == EINTR)
+			goto again;
+
+		return -1;
+	}
+
+	if (!WIFEXITED(status))
+		return -1;
+
+	return WEXITSTATUS(status);
+}
+
+static int setid_userns_root(void)
+{
+	if (setuid(0))
+		return -1;
+	if (setgid(0))
+		return -1;
+
+	setfsuid(0);
+	setfsgid(0);
+
+	return 0;
+}
+
+enum idmap_type {
+	UID_MAP,
+	GID_MAP,
+};
+
+static ssize_t read_nointr(int fd, void *buf, size_t count)
+{
+	ssize_t ret;
+again:
+	ret = read(fd, buf, count);
+	if (ret < 0 && errno == EINTR)
+		goto again;
+
+	return ret;
+}
+
+static ssize_t write_nointr(int fd, const void *buf, size_t count)
+{
+	ssize_t ret;
+again:
+	ret = write(fd, buf, count);
+	if (ret < 0 && errno == EINTR)
+		goto again;
+
+	return ret;
+}
+
+static int write_id_mapping(enum idmap_type type, pid_t pid, const char *buf,
+			    size_t buf_size)
+{
+	int fd;
+	int ret;
+	char path[4096];
+
+	if (type == GID_MAP) {
+		int setgroups_fd;
+
+		snprintf(path, sizeof(path), "/proc/%d/setgroups", pid);
+		setgroups_fd = open(path, O_WRONLY | O_CLOEXEC | O_NOFOLLOW);
+		if (setgroups_fd < 0 && errno != ENOENT)
+			return -1;
+
+		if (setgroups_fd >= 0) {
+			ret = write_nointr(setgroups_fd, "deny", sizeof("deny") - 1);
+			close_prot_errno_disarm(setgroups_fd);
+			if (ret != sizeof("deny") - 1)
+				return -1;
+		}
+	}
+
+	switch (type) {
+	case UID_MAP:
+		ret = snprintf(path, sizeof(path), "/proc/%d/uid_map", pid);
+		break;
+	case GID_MAP:
+		ret = snprintf(path, sizeof(path), "/proc/%d/gid_map", pid);
+		break;
+	default:
+		return -1;
+	}
+	if (ret < 0 || ret >= sizeof(path))
+		return -E2BIG;
+
+	fd = open(path, O_WRONLY | O_CLOEXEC | O_NOFOLLOW);
+	if (fd < 0)
+		return -1;
+
+	ret = write_nointr(fd, buf, buf_size);
+	close_prot_errno_disarm(fd);
+	if (ret != buf_size)
+		return -1;
+
+	return 0;
+}
+
+static void change_userns(struct __test_metadata *_metadata, int syncfds[2])
+{
+	int ret;
+	char buf;
+
+	close_prot_errno_disarm(syncfds[1]);
+
+	ret = unshare(CLONE_NEWUSER);
+	ASSERT_EQ(ret, 0) {
+		TH_LOG("%s - Failed to unshare user namespace",
+			strerror(errno));
+	}
+
+	ret = write_nointr(syncfds[0], "1", 1);
+	ASSERT_EQ(ret, 1) {
+		TH_LOG("write_nointr() failed");
+	}
+
+	ret = read_nointr(syncfds[0], &buf, 1);
+	ASSERT_EQ(ret, 1) {
+		TH_LOG("read_nointr() failed");
+	}
+
+	close_prot_errno_disarm(syncfds[0]);
+
+	ASSERT_EQ(setid_userns_root(), 0) {
+		TH_LOG("setid_userns_root() failed");
+	}
+}
+
+static void change_idmaps(struct __test_metadata *_metadata, int syncfds[2], pid_t pid)
+{
+	int ret;
+	char buf;
+	char id_map[4096];
+
+	close_prot_errno_disarm(syncfds[0]);
+
+	ret = read_nointr(syncfds[1], &buf, 1);
+	ASSERT_EQ(ret, 1) {
+		TH_LOG("read_nointr() failed");
+	}
+
+	snprintf(id_map, sizeof(id_map), "0 %d 1\n", getuid());
+	ret = write_id_mapping(UID_MAP, pid, id_map, strlen(id_map));
+	ASSERT_EQ(ret, 0) {
+		TH_LOG("write_id_mapping(UID_MAP) failed");
+	}
+
+	snprintf(id_map, sizeof(id_map), "0 %d 1\n", getgid());
+	ret = write_id_mapping(GID_MAP, pid, id_map, strlen(id_map));
+	ASSERT_EQ(ret, 0) {
+		TH_LOG("write_id_mapping(GID_MAP) failed");
+	}
+
+	ret = write_nointr(syncfds[1], "1", 1);
+	ASSERT_EQ(ret, 1) {
+		TH_LOG("write_nointr() failed");
+	}
+
+	close_prot_errno_disarm(syncfds[1]);
+}
+
+struct __test_metadata *_thread_metadata;
+static void *binder_version_thread(void *data)
+{
+	struct __test_metadata *_metadata = _thread_metadata;
+	int fd = PTR_TO_INT(data);
+	struct binder_version version = { 0 };
+	int ret;
+
+	ret = ioctl(fd, BINDER_VERSION, &version);
+	if (ret < 0)
+		TH_LOG("%s - Failed to open perform BINDER_VERSION request\n",
+			strerror(errno));
+
+	pthread_exit(data);
+}
+
+/*
+ * Regression test:
+ * 2669b8b0c798 ("binder: prevent UAF for binderfs devices")
+ * f0fe2c0f050d ("binder: prevent UAF for binderfs devices II")
+ * 211b64e4b5b6 ("binderfs: use refcount for binder control devices too")
+ */
+TEST(binderfs_stress)
+{
+	int fds[1000];
+	int syncfds[2];
+	pid_t pid;
+	int fd, ret;
+	size_t len;
+	struct binderfs_device device = { 0 };
+	char binderfs_mntpt[] = P_tmpdir "/binderfs_XXXXXX",
+		device_path[sizeof(P_tmpdir "/binderfs_XXXXXX/") + BINDERFS_MAX_NAME];
+
+	ret = socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, syncfds);
+	ASSERT_EQ(ret, 0) {
+		TH_LOG("%s - Failed to create socket pair", strerror(errno));
+	}
+
+	pid = fork();
+	ASSERT_GE(pid, 0) {
+		TH_LOG("%s - Failed to fork", strerror(errno));
+		close_prot_errno_disarm(syncfds[0]);
+		close_prot_errno_disarm(syncfds[1]);
+	}
+
+	if (pid == 0) {
+		int i, j, k, nthreads;
+		pthread_attr_t attr;
+		pthread_t threads[DEFAULT_THREADS];
+		change_userns(_metadata, syncfds);
+		change_mountns(_metadata);
+
+		ASSERT_NE(mkdtemp(binderfs_mntpt), NULL) {
+			TH_LOG("%s - Failed to create binderfs mountpoint",
+				strerror(errno));
+		}
+
+		ret = mount(NULL, binderfs_mntpt, "binder", 0, 0);
+		ASSERT_EQ(ret, 0) {
+			TH_LOG("%s - Failed to mount binderfs", strerror(errno));
+		}
+
+		for (int i = 0; i < ARRAY_SIZE(fds); i++) {
+
+			snprintf(device_path, sizeof(device_path),
+				 "%s/binder-control", binderfs_mntpt);
+			fd = open(device_path, O_RDONLY | O_CLOEXEC);
+			ASSERT_GE(fd, 0) {
+				TH_LOG("%s - Failed to open binder-control device",
+					strerror(errno));
+			}
+
+			memset(&device, 0, sizeof(device));
+			snprintf(device.name, sizeof(device.name), "%d", i);
+			ret = ioctl(fd, BINDER_CTL_ADD, &device);
+			close_prot_errno_disarm(fd);
+			ASSERT_EQ(ret, 0) {
+				TH_LOG("%s - Failed to allocate new binder device",
+					strerror(errno));
+			}
+
+			snprintf(device_path, sizeof(device_path), "%s/%d",
+				 binderfs_mntpt, i);
+			fds[i] = open(device_path, O_RDONLY | O_CLOEXEC);
+			ASSERT_GE(fds[i], 0) {
+				TH_LOG("%s - Failed to open binder device", strerror(errno));
+			}
+		}
+
+		ret = umount2(binderfs_mntpt, MNT_DETACH);
+		ASSERT_EQ(ret, 0) {
+			TH_LOG("%s - Failed to unmount binderfs", strerror(errno));
+			rmdir(binderfs_mntpt);
+		}
+
+		nthreads = get_nprocs_conf();
+		if (nthreads > DEFAULT_THREADS)
+			nthreads = DEFAULT_THREADS;
+
+		_thread_metadata = _metadata;
+		pthread_attr_init(&attr);
+		for (k = 0; k < ARRAY_SIZE(fds); k++) {
+			for (i = 0; i < nthreads; i++) {
+				ret = pthread_create(&threads[i], &attr, binder_version_thread, INT_TO_PTR(fds[k]));
+				if (ret) {
+					TH_LOG("%s - Failed to create thread %d",
+						strerror(errno), i);
+					break;
+				}
+			}
+
+			for (j = 0; j < i; j++) {
+				void *fdptr = NULL;
+
+				ret = pthread_join(threads[j], &fdptr);
+				if (ret)
+					TH_LOG("%s - Failed to join thread %d for fd %d",
+						strerror(errno), j, PTR_TO_INT(fdptr));
+			}
+		}
+		pthread_attr_destroy(&attr);
+
+		for (k = 0; k < ARRAY_SIZE(fds); k++)
+			close(fds[k]);
+
+		exit(EXIT_SUCCESS);
+	}
+
+	change_idmaps(_metadata, syncfds, pid);
+
+	ret = wait_for_pid(pid);
+	ASSERT_EQ(ret, 0) {
+		TH_LOG("wait_for_pid() failed");
+	}
+}
+
+TEST(binderfs_test_privileged)
+{
+	if (geteuid() != 0)
+		SKIP(return, "Tests are not run as root. Skipping privileged tests");
+
+	if (__do_binderfs_test(_metadata))
+		SKIP(return, "The Android binderfs filesystem is not available");
+}
+
+TEST(binderfs_test_unprivileged)
+{
+	int ret;
+	int syncfds[2];
+	pid_t pid;
+
+	ret = socketpair(PF_LOCAL, SOCK_STREAM | SOCK_CLOEXEC, 0, syncfds);
+	ASSERT_EQ(ret, 0) {
+		TH_LOG("%s - Failed to create socket pair", strerror(errno));
+	}
+
+	pid = fork();
+	ASSERT_GE(pid, 0) {
+		close_prot_errno_disarm(syncfds[0]);
+		close_prot_errno_disarm(syncfds[1]);
+		TH_LOG("%s - Failed to fork", strerror(errno));
+	}
+
+	if (pid == 0) {
+		change_userns(_metadata, syncfds);
+		if (__do_binderfs_test(_metadata))
+			exit(2);
+		exit(EXIT_SUCCESS);
+	}
+
+	change_idmaps(_metadata, syncfds, pid);
+
+	ret = wait_for_pid(pid);
+	if (ret) {
+		if (ret == 2)
+			SKIP(return, "The Android binderfs filesystem is not available");
+		ASSERT_EQ(ret, 0) {
+			TH_LOG("wait_for_pid() failed");
+		}
+	}
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/filesystems/binderfs/config b/tools/testing/selftests/filesystems/binderfs/config
new file mode 100644
index 000000000..02dd6cc9c
--- /dev/null
+++ b/tools/testing/selftests/filesystems/binderfs/config
@@ -0,0 +1,3 @@
+CONFIG_ANDROID=y
+CONFIG_ANDROID_BINDERFS=y
+CONFIG_ANDROID_BINDER_IPC=y