Add an additional test to ensure that bpf_lookup_user_key() creates a referenced special keyring when the KEY_LOOKUP_CREATE flag is passed to this function.
Also ensure that the helper rejects invalid flags.
Signed-off-by: Roberto Sassu roberto.sassu@huawei.com --- .../bpf/prog_tests/lookup_user_key.c | 94 +++++++++++++++++++ .../bpf/progs/test_lookup_user_key.c | 35 +++++++ 2 files changed, 129 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/lookup_user_key.c create mode 100644 tools/testing/selftests/bpf/progs/test_lookup_user_key.c
diff --git a/tools/testing/selftests/bpf/prog_tests/lookup_user_key.c b/tools/testing/selftests/bpf/prog_tests/lookup_user_key.c new file mode 100644 index 000000000000..6487699d30f6 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/lookup_user_key.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu roberto.sassu@huawei.com + */ + +#include <linux/keyctl.h> +#include <test_progs.h> + +#include "test_lookup_user_key.skel.h" + +#define LOG_BUF_SIZE 16384 + +#define KEY_LOOKUP_CREATE 0x01 +#define KEY_LOOKUP_PARTIAL 0x02 + +void test_lookup_user_key(void) +{ + char *buf = NULL; + struct test_lookup_user_key *skel = NULL; + u32 next_id; + int ret; + + LIBBPF_OPTS(bpf_object_open_opts, opts); + + buf = malloc(LOG_BUF_SIZE); + if (!ASSERT_OK_PTR(buf, "malloc")) + goto close_prog; + + opts.kernel_log_buf = buf; + opts.kernel_log_size = LOG_BUF_SIZE; + opts.kernel_log_level = 1; + + skel = test_lookup_user_key__open_opts(&opts); + if (!ASSERT_OK_PTR(skel, "test_lookup_user_key__open_opts")) + goto close_prog; + + ret = test_lookup_user_key__load(skel); + + if (ret < 0 && strstr(buf, "unknown func bpf_lookup_user_key")) { + printf("%s:SKIP:bpf_lookup_user_key() helper not supported\n", + __func__); + test__skip(); + goto close_prog; + } + + if (!ASSERT_OK(ret, "test_lookup_user_key__load")) + goto close_prog; + + ret = test_lookup_user_key__attach(skel); + if (!ASSERT_OK(ret, "test_lookup_user_key__attach")) + goto close_prog; + + skel->bss->monitored_pid = getpid(); + skel->bss->key_serial = KEY_SPEC_THREAD_KEYRING; + + /* The thread-specific keyring does not exist, this test fails. */ + skel->bss->flags = 0; + + ret = bpf_prog_get_next_id(0, &next_id); + if (!ASSERT_LT(ret, 0, "bpf_prog_get_next_id")) + goto close_prog; + + /* Force creation of the thread-specific keyring, this test succeeds. */ + skel->bss->flags = KEY_LOOKUP_CREATE; + + ret = bpf_prog_get_next_id(0, &next_id); + if (!ASSERT_OK(ret, "bpf_prog_get_next_id")) + goto close_prog; + + /* Pass both lookup flags for parameter validation. */ + skel->bss->flags = KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL; + + ret = bpf_prog_get_next_id(0, &next_id); + if (!ASSERT_OK(ret, "bpf_prog_get_next_id")) + goto close_prog; + + /* Pass invalid flags. */ + skel->bss->flags = UINT64_MAX; + + ret = bpf_prog_get_next_id(0, &next_id); + ASSERT_LT(ret, 0, "bpf_prog_get_next_id"); + +close_prog: + free(buf); + + if (!skel) + return; + + skel->bss->monitored_pid = 0; + test_lookup_user_key__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_lookup_user_key.c b/tools/testing/selftests/bpf/progs/test_lookup_user_key.c new file mode 100644 index 000000000000..5b63753ba163 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_lookup_user_key.c @@ -0,0 +1,35 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu roberto.sassu@huawei.com + */ + +#include <errno.h> +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +char _license[] SEC("license") = "GPL"; + +__u32 monitored_pid; +__u32 key_serial; +__u64 flags; + +SEC("lsm.s/bpf") +int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size) +{ + struct key *key; + __u32 pid; + + pid = bpf_get_current_pid_tgid() >> 32; + if (pid != monitored_pid) + return 0; + + key = bpf_lookup_user_key(key_serial, flags); + if (key) + bpf_key_put(key); + + return (key) ? 0 : -ENOENT; +}