From: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
Test cases we care about and ensure improper usage is caught and
rejected by verifier. This also ends up exercising acquire release
pair logic and MEM_RDONLY's effect on a PTR_TO_BTF_ID which usually
permits BPF_WRITE.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx>
Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
---
.../testing/selftests/bpf/prog_tests/bpf_nf.c | 52 ++++++++++++-
.../selftests/bpf/progs/test_bpf_nf_fail.c | 73 +++++++++++++++++++
2 files changed, 124 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/bpf/progs/test_bpf_nf_fail.c
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_nf.c b/tools/testing/selftests/bpf/prog_tests/bpf_nf.c
index b909928427f3..d7294c6451d0 100644
--- a/tools/testing/selftests/bpf/prog_tests/bpf_nf.c
+++ b/tools/testing/selftests/bpf/prog_tests/bpf_nf.c
@@ -2,13 +2,25 @@
#include <test_progs.h>
#include <network_helpers.h>
#include "test_bpf_nf.skel.h"
+#include "test_bpf_nf_fail.skel.h"
+
+static char log_buf[1024 * 1024];
+
+struct {
+ const char *prog_name;
+ const char *err_msg;
+} test_bpf_nf_fail_tests[] = {
+ { "alloc_release", "not permitted to release reference" },
+ { "write_after_insert", "pointer points to const object, only read is supported" },
+ { "lookup_insert", "cannot pass read only pointer to arg#0" },
+};
enum {
TEST_XDP,
TEST_TC_BPF,
};
-void test_bpf_nf_ct(int mode)
+static void test_bpf_nf_ct(int mode)
{
struct test_bpf_nf *skel;
int prog_fd, err;
@@ -49,10 +61,48 @@ void test_bpf_nf_ct(int mode)
test_bpf_nf__destroy(skel);
}
+static void test_bpf_nf_ct_fail(const char *prog_name, const char *err_msg)
+{
+ LIBBPF_OPTS(bpf_object_open_opts, opts, .kernel_log_buf = log_buf,
+ .kernel_log_size = sizeof(log_buf),
+ .kernel_log_level = 1);
+ struct test_bpf_nf_fail *skel;
+ struct bpf_program *prog;
+ int ret;
+
+ skel = test_bpf_nf_fail__open_opts(&opts);
+ if (!ASSERT_OK_PTR(skel, "test_bpf_nf_fail__open"))
+ return;
+
+ prog = bpf_object__find_program_by_name(skel->obj, prog_name);
+ if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
+ goto end;
+
+ bpf_program__set_autoload(prog, true);
+
+ ret = test_bpf_nf_fail__load(skel);
+ if (!ASSERT_ERR(ret, "test_bpf_nf_fail__load must fail"))
+ goto end;
+
+ if (!ASSERT_OK_PTR(strstr(log_buf, err_msg), "expected error message")) {
+ fprintf(stderr, "Expected: %s\n", err_msg);
+ fprintf(stderr, "Verifier: %s\n", log_buf);
+ }
+
+end:
+ test_bpf_nf_fail__destroy(skel);
+}
+
void test_bpf_nf(void)
{
+ int i;
if (test__start_subtest("xdp-ct"))
test_bpf_nf_ct(TEST_XDP);
if (test__start_subtest("tc-bpf-ct"))
test_bpf_nf_ct(TEST_TC_BPF);
+ for (i = 0; i < ARRAY_SIZE(test_bpf_nf_fail_tests); i++) {
+ if (test__start_subtest(test_bpf_nf_fail_tests[i].prog_name))
+ test_bpf_nf_ct_fail(test_bpf_nf_fail_tests[i].prog_name,
+ test_bpf_nf_fail_tests[i].err_msg);
+ }
}
diff --git a/tools/testing/selftests/bpf/progs/test_bpf_nf_fail.c b/tools/testing/selftests/bpf/progs/test_bpf_nf_fail.c
new file mode 100644
index 000000000000..2484f7baef90
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_bpf_nf_fail.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <vmlinux.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+
+struct nf_conn;
+
+struct nf_conn___local {;
+ unsigned long status;
+} __attribute__((preserve_access_index));
+
+struct bpf_ct_opts___local {
+ s32 netns_id;
+ s32 error;
+ u8 l4proto;
+ u8 reserved[3];
+} __attribute__((preserve_access_index));
+
+struct nf_conn *bpf_skb_ct_alloc(struct __sk_buff *, struct bpf_sock_tuple *, u32,
+ struct bpf_ct_opts___local *, u32) __ksym;
+const struct nf_conn *bpf_skb_ct_lookup(struct __sk_buff *, struct bpf_sock_tuple *, u32,
+ struct bpf_ct_opts___local *, u32) __ksym;
+const struct nf_conn *
+bpf_ct_insert_entry(struct nf_conn *, struct bpf_ct_opts___local *, u32) __ksym;
+void bpf_ct_release(const struct nf_conn *) __ksym;
+
+SEC("?tc")
+int alloc_release(struct __sk_buff *ctx)
+{
+ struct bpf_ct_opts___local opts = {};
+ struct bpf_sock_tuple tup = {};
+ struct nf_conn *ct;
+
+ ct = bpf_skb_ct_alloc(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts));
+ if (!ct)
+ return 0;
+ bpf_ct_release(ct);
+ return 0;
+}
+
+SEC("?tc")
+int write_after_insert(struct __sk_buff *ctx)
+{
+ struct bpf_ct_opts___local opts = {};
+ struct bpf_sock_tuple tup = {};
+ struct nf_conn___local *ct;
+
+ ct = (void *)bpf_skb_ct_alloc(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts));
+ if (!ct)
+ return 0;
+ ct = (void *)bpf_ct_insert_entry((void *)ct, &opts, sizeof(opts));
+ if (!ct)
+ return 0;
+ ct->status = 0;
+ return 0;
+}
+
+SEC("?tc")
+int lookup_insert(struct __sk_buff *ctx)
+{
+ struct bpf_ct_opts___local opts = {};
+ struct bpf_sock_tuple tup = {};
+ struct nf_conn *ct;
+
+ ct = (void *)bpf_skb_ct_lookup(ctx, &tup, sizeof(tup.ipv4), &opts, sizeof(opts));
+ if (!ct)
+ return 0;
+ bpf_ct_insert_entry(ct, &opts, sizeof(opts));
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
--
2.35.3
