From: Roberto Sassu <[email protected]>
Add tests to ensure that only supported dynamic pointer types are accepted,
that the passed argument is actually a dynamic pointer, and that the passed
argument is a pointer to the stack.
The tests are currently in the deny list for s390x (JIT does not support
calling kernel function).
Signed-off-by: Roberto Sassu <[email protected]>
---
tools/testing/selftests/bpf/DENYLIST.s390x | 1 +
.../bpf/prog_tests/kfunc_dynptr_param.c | 103 ++++++++++++++++++
.../bpf/progs/test_kfunc_dynptr_param.c | 57 ++++++++++
3 files changed, 161 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
create mode 100644 tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x
index 4e305baa5277..9a6dc3671c65 100644
--- a/tools/testing/selftests/bpf/DENYLIST.s390x
+++ b/tools/testing/selftests/bpf/DENYLIST.s390x
@@ -71,3 +71,4 @@ cgroup_hierarchical_stats # JIT does not support calling kernel f
htab_update # failed to attach: ERROR: strerror_r(-524)=22 (trampoline)
lookup_key # JIT does not support calling kernel function (kfunc)
verify_pkcs7_sig # JIT does not support calling kernel function (kfunc)
+kfunc_dynptr_param # JIT does not support calling kernel function (kfunc)
diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
new file mode 100644
index 000000000000..ea655a5c9d8b
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (c) 2022 Facebook
+ * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <[email protected]>
+ */
+
+#include <test_progs.h>
+#include "test_kfunc_dynptr_param.skel.h"
+
+static size_t log_buf_sz = 1048576; /* 1 MB */
+static char obj_log_buf[1048576];
+
+static struct {
+ const char *prog_name;
+ const char *expected_err_msg;
+} kfunc_dynptr_tests[] = {
+ {"dynptr_type_not_supp",
+ "arg#0 pointer type STRUCT bpf_dynptr_kern points to unsupported dynamic pointer type"},
+ {"not_valid_dynptr",
+ "arg#0 pointer type STRUCT bpf_dynptr_kern must be valid and initialized"},
+ {"not_ptr_to_stack", "arg#0 pointer type STRUCT bpf_dynptr_kern not to stack"},
+};
+
+static bool kfunc_not_supported;
+
+static int libbpf_print_cb(enum libbpf_print_level level, const char *fmt,
+ va_list args)
+{
+ if (strcmp(fmt, "libbpf: extern (func ksym) '%s': not found in kernel or module BTFs\n"))
+ return 0;
+
+ if (strcmp(va_arg(args, char *), "bpf_verify_pkcs7_signature"))
+ return 0;
+
+ kfunc_not_supported = true;
+ return 0;
+}
+
+static void verify_fail(const char *prog_name, const char *expected_err_msg)
+{
+ struct test_kfunc_dynptr_param *skel;
+ LIBBPF_OPTS(bpf_object_open_opts, opts);
+ libbpf_print_fn_t old_print_cb;
+ struct bpf_program *prog;
+ int err;
+
+ opts.kernel_log_buf = obj_log_buf;
+ opts.kernel_log_size = log_buf_sz;
+ opts.kernel_log_level = 1;
+
+ skel = test_kfunc_dynptr_param__open_opts(&opts);
+ if (!ASSERT_OK_PTR(skel, "test_kfunc_dynptr_param__open_opts"))
+ goto cleanup;
+
+ prog = bpf_object__find_program_by_name(skel->obj, prog_name);
+ if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
+ goto cleanup;
+
+ bpf_program__set_autoload(prog, true);
+
+ bpf_map__set_max_entries(skel->maps.ringbuf, getpagesize());
+
+ kfunc_not_supported = false;
+
+ old_print_cb = libbpf_set_print(libbpf_print_cb);
+ err = test_kfunc_dynptr_param__load(skel);
+ libbpf_set_print(old_print_cb);
+
+ if (err < 0 && kfunc_not_supported) {
+ fprintf(stderr,
+ "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not supported\n",
+ __func__);
+ test__skip();
+ goto cleanup;
+ }
+
+ if (!ASSERT_ERR(err, "unexpected load success"))
+ goto cleanup;
+
+ if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg), "expected_err_msg")) {
+ fprintf(stderr, "Expected err_msg: %s\n", expected_err_msg);
+ fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
+ }
+
+cleanup:
+ test_kfunc_dynptr_param__destroy(skel);
+}
+
+void test_kfunc_dynptr_param(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(kfunc_dynptr_tests); i++) {
+ if (!test__start_subtest(kfunc_dynptr_tests[i].prog_name))
+ continue;
+
+ verify_fail(kfunc_dynptr_tests[i].prog_name,
+ kfunc_dynptr_tests[i].expected_err_msg);
+ }
+}
diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
new file mode 100644
index 000000000000..2f09f91a1576
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
@@ -0,0 +1,57 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <[email protected]>
+ */
+
+#include "vmlinux.h"
+#include <errno.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct bpf_dynptr {
+ __u64 :64;
+ __u64 :64;
+} __attribute__((aligned(8)));
+
+extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr,
+ struct bpf_dynptr *sig_ptr,
+ struct bpf_key *trusted_keyring) __ksym;
+
+struct {
+ __uint(type, BPF_MAP_TYPE_RINGBUF);
+} ringbuf SEC(".maps");
+
+char _license[] SEC("license") = "GPL";
+
+SEC("?lsm.s/bpf")
+int BPF_PROG(dynptr_type_not_supp, int cmd, union bpf_attr *attr,
+ unsigned int size)
+{
+ char write_data[64] = "hello there, world!!";
+ struct bpf_dynptr ptr;
+
+ bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0, &ptr);
+
+ return bpf_verify_pkcs7_signature(&ptr, &ptr, NULL);
+}
+
+SEC("?lsm.s/bpf")
+int BPF_PROG(not_valid_dynptr, int cmd, union bpf_attr *attr, unsigned int size)
+{
+ unsigned long val;
+
+ return bpf_verify_pkcs7_signature((struct bpf_dynptr *)&val,
+ (struct bpf_dynptr *)&val, NULL);
+}
+
+SEC("?lsm.s/bpf")
+int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr, unsigned int size)
+{
+ unsigned long val;
+
+ return bpf_verify_pkcs7_signature((struct bpf_dynptr *)val,
+ (struct bpf_dynptr *)val, NULL);
+}
--
2.25.1
On Mon, 5 Sept 2022 at 16:36, Roberto Sassu
<[email protected]> wrote:
>
> From: Roberto Sassu <[email protected]>
>
> Add tests to ensure that only supported dynamic pointer types are accepted,
> that the passed argument is actually a dynamic pointer, and that the passed
> argument is a pointer to the stack.
>
> The tests are currently in the deny list for s390x (JIT does not support
> calling kernel function).
>
> Signed-off-by: Roberto Sassu <[email protected]>
> ---
> tools/testing/selftests/bpf/DENYLIST.s390x | 1 +
> .../bpf/prog_tests/kfunc_dynptr_param.c | 103 ++++++++++++++++++
> .../bpf/progs/test_kfunc_dynptr_param.c | 57 ++++++++++
> 3 files changed, 161 insertions(+)
> create mode 100644 tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> create mode 100644 tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
>
> diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x
> index 4e305baa5277..9a6dc3671c65 100644
> --- a/tools/testing/selftests/bpf/DENYLIST.s390x
> +++ b/tools/testing/selftests/bpf/DENYLIST.s390x
> @@ -71,3 +71,4 @@ cgroup_hierarchical_stats # JIT does not support calling kernel f
> htab_update # failed to attach: ERROR: strerror_r(-524)=22 (trampoline)
> lookup_key # JIT does not support calling kernel function (kfunc)
> verify_pkcs7_sig # JIT does not support calling kernel function (kfunc)
> +kfunc_dynptr_param # JIT does not support calling kernel function (kfunc)
> diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> new file mode 100644
> index 000000000000..ea655a5c9d8b
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> @@ -0,0 +1,103 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * Copyright (c) 2022 Facebook
> + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <[email protected]>
> + */
> +
> +#include <test_progs.h>
> +#include "test_kfunc_dynptr_param.skel.h"
> +
> +static size_t log_buf_sz = 1048576; /* 1 MB */
> +static char obj_log_buf[1048576];
> +
> +static struct {
> + const char *prog_name;
> + const char *expected_err_msg;
> +} kfunc_dynptr_tests[] = {
> + {"dynptr_type_not_supp",
> + "arg#0 pointer type STRUCT bpf_dynptr_kern points to unsupported dynamic pointer type"},
> + {"not_valid_dynptr",
> + "arg#0 pointer type STRUCT bpf_dynptr_kern must be valid and initialized"},
> + {"not_ptr_to_stack", "arg#0 pointer type STRUCT bpf_dynptr_kern not to stack"},
> +};
> +
> +static bool kfunc_not_supported;
> +
> +static int libbpf_print_cb(enum libbpf_print_level level, const char *fmt,
> + va_list args)
> +{
> + if (strcmp(fmt, "libbpf: extern (func ksym) '%s': not found in kernel or module BTFs\n"))
> + return 0;
> +
> + if (strcmp(va_arg(args, char *), "bpf_verify_pkcs7_signature"))
> + return 0;
> +
> + kfunc_not_supported = true;
> + return 0;
> +}
> +
> +static void verify_fail(const char *prog_name, const char *expected_err_msg)
> +{
> + struct test_kfunc_dynptr_param *skel;
> + LIBBPF_OPTS(bpf_object_open_opts, opts);
> + libbpf_print_fn_t old_print_cb;
> + struct bpf_program *prog;
> + int err;
> +
> + opts.kernel_log_buf = obj_log_buf;
> + opts.kernel_log_size = log_buf_sz;
> + opts.kernel_log_level = 1;
> +
> + skel = test_kfunc_dynptr_param__open_opts(&opts);
> + if (!ASSERT_OK_PTR(skel, "test_kfunc_dynptr_param__open_opts"))
> + goto cleanup;
> +
> + prog = bpf_object__find_program_by_name(skel->obj, prog_name);
> + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
> + goto cleanup;
> +
> + bpf_program__set_autoload(prog, true);
> +
> + bpf_map__set_max_entries(skel->maps.ringbuf, getpagesize());
> +
> + kfunc_not_supported = false;
> +
> + old_print_cb = libbpf_set_print(libbpf_print_cb);
> + err = test_kfunc_dynptr_param__load(skel);
> + libbpf_set_print(old_print_cb);
> +
> + if (err < 0 && kfunc_not_supported) {
> + fprintf(stderr,
> + "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not supported\n",
> + __func__);
> + test__skip();
> + goto cleanup;
> + }
> +
> + if (!ASSERT_ERR(err, "unexpected load success"))
> + goto cleanup;
> +
> + if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg), "expected_err_msg")) {
> + fprintf(stderr, "Expected err_msg: %s\n", expected_err_msg);
> + fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
> + }
> +
> +cleanup:
> + test_kfunc_dynptr_param__destroy(skel);
> +}
> +
> +void test_kfunc_dynptr_param(void)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(kfunc_dynptr_tests); i++) {
> + if (!test__start_subtest(kfunc_dynptr_tests[i].prog_name))
> + continue;
> +
> + verify_fail(kfunc_dynptr_tests[i].prog_name,
> + kfunc_dynptr_tests[i].expected_err_msg);
> + }
> +}
> diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> new file mode 100644
> index 000000000000..2f09f91a1576
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> @@ -0,0 +1,57 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <[email protected]>
> + */
> +
> +#include "vmlinux.h"
> +#include <errno.h>
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +
> +struct bpf_dynptr {
> + __u64 :64;
> + __u64 :64;
> +} __attribute__((aligned(8)));
> +
> +extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr,
> + struct bpf_dynptr *sig_ptr,
> + struct bpf_key *trusted_keyring) __ksym;
> +
> +struct {
> + __uint(type, BPF_MAP_TYPE_RINGBUF);
> +} ringbuf SEC(".maps");
> +
> +char _license[] SEC("license") = "GPL";
> +
> +SEC("?lsm.s/bpf")
> +int BPF_PROG(dynptr_type_not_supp, int cmd, union bpf_attr *attr,
> + unsigned int size)
> +{
> + char write_data[64] = "hello there, world!!";
> + struct bpf_dynptr ptr;
> +
> + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0, &ptr);
> +
> + return bpf_verify_pkcs7_signature(&ptr, &ptr, NULL);
> +}
> +
> +SEC("?lsm.s/bpf")
> +int BPF_PROG(not_valid_dynptr, int cmd, union bpf_attr *attr, unsigned int size)
> +{
> + unsigned long val;
> +
> + return bpf_verify_pkcs7_signature((struct bpf_dynptr *)&val,
> + (struct bpf_dynptr *)&val, NULL);
> +}
> +
> +SEC("?lsm.s/bpf")
> +int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr, unsigned int size)
> +{
> + unsigned long val;
> +
> + return bpf_verify_pkcs7_signature((struct bpf_dynptr *)val,
> + (struct bpf_dynptr *)val, NULL);
Please also include a test where you cause the dynptr to be set to
NULL, e.g. by passing invalid stuff to ringbuf_reserve_dynptr, and
then try to pass it to bpf_verify_pkc7_signature.
> +}
> --
> 2.25.1
>
On Tue, 2022-09-06 at 05:15 +0200, Kumar Kartikeya Dwivedi wrote:
> On Mon, 5 Sept 2022 at 16:36, Roberto Sassu
> <[email protected]> wrote:
> > From: Roberto Sassu <[email protected]>
> >
> > Add tests to ensure that only supported dynamic pointer types are
> > accepted,
> > that the passed argument is actually a dynamic pointer, and that
> > the passed
> > argument is a pointer to the stack.
> >
> > The tests are currently in the deny list for s390x (JIT does not
> > support
> > calling kernel function).
> >
> > Signed-off-by: Roberto Sassu <[email protected]>
> > ---
> > tools/testing/selftests/bpf/DENYLIST.s390x | 1 +
> > .../bpf/prog_tests/kfunc_dynptr_param.c | 103
> > ++++++++++++++++++
> > .../bpf/progs/test_kfunc_dynptr_param.c | 57 ++++++++++
> > 3 files changed, 161 insertions(+)
> > create mode 100644
> > tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> > create mode 100644
> > tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> >
> > diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x
> > b/tools/testing/selftests/bpf/DENYLIST.s390x
> > index 4e305baa5277..9a6dc3671c65 100644
> > --- a/tools/testing/selftests/bpf/DENYLIST.s390x
> > +++ b/tools/testing/selftests/bpf/DENYLIST.s390x
> > @@ -71,3 +71,4 @@ cgroup_hierarchical_stats # JIT
> > does not support calling kernel f
> > htab_update # failed to attach:
> > ERROR: strerror_r(-
> > 524)=22 (trampoline)
> > lookup_key # JIT does not support
> > calling kernel function (kfunc)
> > verify_pkcs7_sig # JIT does not support
> > calling kernel function (kfunc)
> > +kfunc_dynptr_param # JIT does not support
> > calling kernel function (kfunc)
> > diff --git
> > a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> > b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> > new file mode 100644
> > index 000000000000..ea655a5c9d8b
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> > @@ -0,0 +1,103 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +/*
> > + * Copyright (c) 2022 Facebook
> > + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
> > + *
> > + * Author: Roberto Sassu <[email protected]>
> > + */
> > +
> > +#include <test_progs.h>
> > +#include "test_kfunc_dynptr_param.skel.h"
> > +
> > +static size_t log_buf_sz = 1048576; /* 1 MB */
> > +static char obj_log_buf[1048576];
> > +
> > +static struct {
> > + const char *prog_name;
> > + const char *expected_err_msg;
> > +} kfunc_dynptr_tests[] = {
> > + {"dynptr_type_not_supp",
> > + "arg#0 pointer type STRUCT bpf_dynptr_kern points to
> > unsupported dynamic pointer type"},
> > + {"not_valid_dynptr",
> > + "arg#0 pointer type STRUCT bpf_dynptr_kern must be valid
> > and initialized"},
> > + {"not_ptr_to_stack", "arg#0 pointer type STRUCT
> > bpf_dynptr_kern not to stack"},
> > +};
> > +
> > +static bool kfunc_not_supported;
> > +
> > +static int libbpf_print_cb(enum libbpf_print_level level, const
> > char *fmt,
> > + va_list args)
> > +{
> > + if (strcmp(fmt, "libbpf: extern (func ksym) '%s': not found
> > in kernel or module BTFs\n"))
> > + return 0;
> > +
> > + if (strcmp(va_arg(args, char *),
> > "bpf_verify_pkcs7_signature"))
> > + return 0;
> > +
> > + kfunc_not_supported = true;
> > + return 0;
> > +}
> > +
> > +static void verify_fail(const char *prog_name, const char
> > *expected_err_msg)
> > +{
> > + struct test_kfunc_dynptr_param *skel;
> > + LIBBPF_OPTS(bpf_object_open_opts, opts);
> > + libbpf_print_fn_t old_print_cb;
> > + struct bpf_program *prog;
> > + int err;
> > +
> > + opts.kernel_log_buf = obj_log_buf;
> > + opts.kernel_log_size = log_buf_sz;
> > + opts.kernel_log_level = 1;
> > +
> > + skel = test_kfunc_dynptr_param__open_opts(&opts);
> > + if (!ASSERT_OK_PTR(skel,
> > "test_kfunc_dynptr_param__open_opts"))
> > + goto cleanup;
> > +
> > + prog = bpf_object__find_program_by_name(skel->obj,
> > prog_name);
> > + if (!ASSERT_OK_PTR(prog,
> > "bpf_object__find_program_by_name"))
> > + goto cleanup;
> > +
> > + bpf_program__set_autoload(prog, true);
> > +
> > + bpf_map__set_max_entries(skel->maps.ringbuf,
> > getpagesize());
> > +
> > + kfunc_not_supported = false;
> > +
> > + old_print_cb = libbpf_set_print(libbpf_print_cb);
> > + err = test_kfunc_dynptr_param__load(skel);
> > + libbpf_set_print(old_print_cb);
> > +
> > + if (err < 0 && kfunc_not_supported) {
> > + fprintf(stderr,
> > + "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not
> > supported\n",
> > + __func__);
> > + test__skip();
> > + goto cleanup;
> > + }
> > +
> > + if (!ASSERT_ERR(err, "unexpected load success"))
> > + goto cleanup;
> > +
> > + if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg),
> > "expected_err_msg")) {
> > + fprintf(stderr, "Expected err_msg: %s\n",
> > expected_err_msg);
> > + fprintf(stderr, "Verifier output: %s\n",
> > obj_log_buf);
> > + }
> > +
> > +cleanup:
> > + test_kfunc_dynptr_param__destroy(skel);
> > +}
> > +
> > +void test_kfunc_dynptr_param(void)
> > +{
> > + int i;
> > +
> > + for (i = 0; i < ARRAY_SIZE(kfunc_dynptr_tests); i++) {
> > + if
> > (!test__start_subtest(kfunc_dynptr_tests[i].prog_name))
> > + continue;
> > +
> > + verify_fail(kfunc_dynptr_tests[i].prog_name,
> > + kfunc_dynptr_tests[i].expected_err_msg)
> > ;
> > + }
> > +}
> > diff --git
> > a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> > b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> > new file mode 100644
> > index 000000000000..2f09f91a1576
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> > @@ -0,0 +1,57 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +
> > +/*
> > + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
> > + *
> > + * Author: Roberto Sassu <[email protected]>
> > + */
> > +
> > +#include "vmlinux.h"
> > +#include <errno.h>
> > +#include <bpf/bpf_helpers.h>
> > +#include <bpf/bpf_tracing.h>
> > +
> > +struct bpf_dynptr {
> > + __u64 :64;
> > + __u64 :64;
> > +} __attribute__((aligned(8)));
> > +
> > +extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr,
> > + struct bpf_dynptr *sig_ptr,
> > + struct bpf_key
> > *trusted_keyring) __ksym;
> > +
> > +struct {
> > + __uint(type, BPF_MAP_TYPE_RINGBUF);
> > +} ringbuf SEC(".maps");
> > +
> > +char _license[] SEC("license") = "GPL";
> > +
> > +SEC("?lsm.s/bpf")
> > +int BPF_PROG(dynptr_type_not_supp, int cmd, union bpf_attr *attr,
> > + unsigned int size)
> > +{
> > + char write_data[64] = "hello there, world!!";
> > + struct bpf_dynptr ptr;
> > +
> > + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0,
> > &ptr);
> > +
> > + return bpf_verify_pkcs7_signature(&ptr, &ptr, NULL);
> > +}
> > +
> > +SEC("?lsm.s/bpf")
> > +int BPF_PROG(not_valid_dynptr, int cmd, union bpf_attr *attr,
> > unsigned int size)
> > +{
> > + unsigned long val;
> > +
> > + return bpf_verify_pkcs7_signature((struct bpf_dynptr
> > *)&val,
> > + (struct bpf_dynptr
> > *)&val, NULL);
> > +}
> > +
> > +SEC("?lsm.s/bpf")
> > +int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr,
> > unsigned int size)
> > +{
> > + unsigned long val;
> > +
> > + return bpf_verify_pkcs7_signature((struct bpf_dynptr *)val,
> > + (struct bpf_dynptr *)val,
> > NULL);
>
> Please also include a test where you cause the dynptr to be set to
> NULL, e.g. by passing invalid stuff to ringbuf_reserve_dynptr, and
> then try to pass it to bpf_verify_pkc7_signature.
Uhm, bpf_ringbuf_reserve_dynptr() is expecting a valid map. How else I
can achieve it?
Thanks
Roberto
On Tue, 6 Sept 2022 at 10:31, Roberto Sassu
<[email protected]> wrote:
>
> On Tue, 2022-09-06 at 05:15 +0200, Kumar Kartikeya Dwivedi wrote:
> > On Mon, 5 Sept 2022 at 16:36, Roberto Sassu
> > <[email protected]> wrote:
> > > From: Roberto Sassu <[email protected]>
> > >
> > > Add tests to ensure that only supported dynamic pointer types are
> > > accepted,
> > > that the passed argument is actually a dynamic pointer, and that
> > > the passed
> > > argument is a pointer to the stack.
> > >
> > > The tests are currently in the deny list for s390x (JIT does not
> > > support
> > > calling kernel function).
> > >
> > > Signed-off-by: Roberto Sassu <[email protected]>
> > > ---
> > > tools/testing/selftests/bpf/DENYLIST.s390x | 1 +
> > > .../bpf/prog_tests/kfunc_dynptr_param.c | 103
> > > ++++++++++++++++++
> > > .../bpf/progs/test_kfunc_dynptr_param.c | 57 ++++++++++
> > > 3 files changed, 161 insertions(+)
> > > create mode 100644
> > > tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> > > create mode 100644
> > > tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> > >
> > > diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x
> > > b/tools/testing/selftests/bpf/DENYLIST.s390x
> > > index 4e305baa5277..9a6dc3671c65 100644
> > > --- a/tools/testing/selftests/bpf/DENYLIST.s390x
> > > +++ b/tools/testing/selftests/bpf/DENYLIST.s390x
> > > @@ -71,3 +71,4 @@ cgroup_hierarchical_stats # JIT
> > > does not support calling kernel f
> > > htab_update # failed to attach:
> > > ERROR: strerror_r(-
> > > 524)=22 (trampoline)
> > > lookup_key # JIT does not support
> > > calling kernel function (kfunc)
> > > verify_pkcs7_sig # JIT does not support
> > > calling kernel function (kfunc)
> > > +kfunc_dynptr_param # JIT does not support
> > > calling kernel function (kfunc)
> > > diff --git
> > > a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> > > b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> > > new file mode 100644
> > > index 000000000000..ea655a5c9d8b
> > > --- /dev/null
> > > +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
> > > @@ -0,0 +1,103 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +
> > > +/*
> > > + * Copyright (c) 2022 Facebook
> > > + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
> > > + *
> > > + * Author: Roberto Sassu <[email protected]>
> > > + */
> > > +
> > > +#include <test_progs.h>
> > > +#include "test_kfunc_dynptr_param.skel.h"
> > > +
> > > +static size_t log_buf_sz = 1048576; /* 1 MB */
> > > +static char obj_log_buf[1048576];
> > > +
> > > +static struct {
> > > + const char *prog_name;
> > > + const char *expected_err_msg;
> > > +} kfunc_dynptr_tests[] = {
> > > + {"dynptr_type_not_supp",
> > > + "arg#0 pointer type STRUCT bpf_dynptr_kern points to
> > > unsupported dynamic pointer type"},
> > > + {"not_valid_dynptr",
> > > + "arg#0 pointer type STRUCT bpf_dynptr_kern must be valid
> > > and initialized"},
> > > + {"not_ptr_to_stack", "arg#0 pointer type STRUCT
> > > bpf_dynptr_kern not to stack"},
> > > +};
> > > +
> > > +static bool kfunc_not_supported;
> > > +
> > > +static int libbpf_print_cb(enum libbpf_print_level level, const
> > > char *fmt,
> > > + va_list args)
> > > +{
> > > + if (strcmp(fmt, "libbpf: extern (func ksym) '%s': not found
> > > in kernel or module BTFs\n"))
> > > + return 0;
> > > +
> > > + if (strcmp(va_arg(args, char *),
> > > "bpf_verify_pkcs7_signature"))
> > > + return 0;
> > > +
> > > + kfunc_not_supported = true;
> > > + return 0;
> > > +}
> > > +
> > > +static void verify_fail(const char *prog_name, const char
> > > *expected_err_msg)
> > > +{
> > > + struct test_kfunc_dynptr_param *skel;
> > > + LIBBPF_OPTS(bpf_object_open_opts, opts);
> > > + libbpf_print_fn_t old_print_cb;
> > > + struct bpf_program *prog;
> > > + int err;
> > > +
> > > + opts.kernel_log_buf = obj_log_buf;
> > > + opts.kernel_log_size = log_buf_sz;
> > > + opts.kernel_log_level = 1;
> > > +
> > > + skel = test_kfunc_dynptr_param__open_opts(&opts);
> > > + if (!ASSERT_OK_PTR(skel,
> > > "test_kfunc_dynptr_param__open_opts"))
> > > + goto cleanup;
> > > +
> > > + prog = bpf_object__find_program_by_name(skel->obj,
> > > prog_name);
> > > + if (!ASSERT_OK_PTR(prog,
> > > "bpf_object__find_program_by_name"))
> > > + goto cleanup;
> > > +
> > > + bpf_program__set_autoload(prog, true);
> > > +
> > > + bpf_map__set_max_entries(skel->maps.ringbuf,
> > > getpagesize());
> > > +
> > > + kfunc_not_supported = false;
> > > +
> > > + old_print_cb = libbpf_set_print(libbpf_print_cb);
> > > + err = test_kfunc_dynptr_param__load(skel);
> > > + libbpf_set_print(old_print_cb);
> > > +
> > > + if (err < 0 && kfunc_not_supported) {
> > > + fprintf(stderr,
> > > + "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not
> > > supported\n",
> > > + __func__);
> > > + test__skip();
> > > + goto cleanup;
> > > + }
> > > +
> > > + if (!ASSERT_ERR(err, "unexpected load success"))
> > > + goto cleanup;
> > > +
> > > + if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg),
> > > "expected_err_msg")) {
> > > + fprintf(stderr, "Expected err_msg: %s\n",
> > > expected_err_msg);
> > > + fprintf(stderr, "Verifier output: %s\n",
> > > obj_log_buf);
> > > + }
> > > +
> > > +cleanup:
> > > + test_kfunc_dynptr_param__destroy(skel);
> > > +}
> > > +
> > > +void test_kfunc_dynptr_param(void)
> > > +{
> > > + int i;
> > > +
> > > + for (i = 0; i < ARRAY_SIZE(kfunc_dynptr_tests); i++) {
> > > + if
> > > (!test__start_subtest(kfunc_dynptr_tests[i].prog_name))
> > > + continue;
> > > +
> > > + verify_fail(kfunc_dynptr_tests[i].prog_name,
> > > + kfunc_dynptr_tests[i].expected_err_msg)
> > > ;
> > > + }
> > > +}
> > > diff --git
> > > a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> > > b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> > > new file mode 100644
> > > index 000000000000..2f09f91a1576
> > > --- /dev/null
> > > +++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
> > > @@ -0,0 +1,57 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +
> > > +/*
> > > + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
> > > + *
> > > + * Author: Roberto Sassu <[email protected]>
> > > + */
> > > +
> > > +#include "vmlinux.h"
> > > +#include <errno.h>
> > > +#include <bpf/bpf_helpers.h>
> > > +#include <bpf/bpf_tracing.h>
> > > +
> > > +struct bpf_dynptr {
> > > + __u64 :64;
> > > + __u64 :64;
> > > +} __attribute__((aligned(8)));
> > > +
> > > +extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr,
> > > + struct bpf_dynptr *sig_ptr,
> > > + struct bpf_key
> > > *trusted_keyring) __ksym;
> > > +
> > > +struct {
> > > + __uint(type, BPF_MAP_TYPE_RINGBUF);
> > > +} ringbuf SEC(".maps");
> > > +
> > > +char _license[] SEC("license") = "GPL";
> > > +
> > > +SEC("?lsm.s/bpf")
> > > +int BPF_PROG(dynptr_type_not_supp, int cmd, union bpf_attr *attr,
> > > + unsigned int size)
> > > +{
> > > + char write_data[64] = "hello there, world!!";
> > > + struct bpf_dynptr ptr;
> > > +
> > > + bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0,
> > > &ptr);
> > > +
> > > + return bpf_verify_pkcs7_signature(&ptr, &ptr, NULL);
> > > +}
> > > +
> > > +SEC("?lsm.s/bpf")
> > > +int BPF_PROG(not_valid_dynptr, int cmd, union bpf_attr *attr,
> > > unsigned int size)
> > > +{
> > > + unsigned long val;
> > > +
> > > + return bpf_verify_pkcs7_signature((struct bpf_dynptr
> > > *)&val,
> > > + (struct bpf_dynptr
> > > *)&val, NULL);
> > > +}
> > > +
> > > +SEC("?lsm.s/bpf")
> > > +int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr,
> > > unsigned int size)
> > > +{
> > > + unsigned long val;
> > > +
> > > + return bpf_verify_pkcs7_signature((struct bpf_dynptr *)val,
> > > + (struct bpf_dynptr *)val,
> > > NULL);
> >
> > Please also include a test where you cause the dynptr to be set to
> > NULL, e.g. by passing invalid stuff to ringbuf_reserve_dynptr, and
> > then try to pass it to bpf_verify_pkc7_signature.
>
> Uhm, bpf_ringbuf_reserve_dynptr() is expecting a valid map. How else I
> can achieve it?
So? Just define a ringbuf map and pass to it? I'm missing why that is
undesirable.
It also needs to be a runtime test, not verifier test, I probably
replied to the wrong patch.
From: Roberto Sassu <[email protected]>
Add tests to ensure that only supported dynamic pointer types are accepted,
that the passed argument is actually a dynamic pointer, that the passed
argument is a pointer to the stack, and that bpf_verify_pkcs7_signature()
correctly handles dynamic pointers with data set to NULL.
The tests are currently in the deny list for s390x (JIT does not support
calling kernel function).
Signed-off-by: Roberto Sassu <[email protected]>
---
tools/testing/selftests/bpf/DENYLIST.s390x | 1 +
.../bpf/prog_tests/kfunc_dynptr_param.c | 164 ++++++++++++++++++
.../bpf/progs/test_kfunc_dynptr_param.c | 99 +++++++++++
3 files changed, 264 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
create mode 100644 tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x
index 4e305baa5277..9a6dc3671c65 100644
--- a/tools/testing/selftests/bpf/DENYLIST.s390x
+++ b/tools/testing/selftests/bpf/DENYLIST.s390x
@@ -71,3 +71,4 @@ cgroup_hierarchical_stats # JIT does not support calling kernel f
htab_update # failed to attach: ERROR: strerror_r(-524)=22 (trampoline)
lookup_key # JIT does not support calling kernel function (kfunc)
verify_pkcs7_sig # JIT does not support calling kernel function (kfunc)
+kfunc_dynptr_param # JIT does not support calling kernel function (kfunc)
diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
new file mode 100644
index 000000000000..c210657d4d0a
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/kfunc_dynptr_param.c
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (c) 2022 Facebook
+ * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <[email protected]>
+ */
+
+#include <test_progs.h>
+#include "test_kfunc_dynptr_param.skel.h"
+
+static size_t log_buf_sz = 1048576; /* 1 MB */
+static char obj_log_buf[1048576];
+
+static struct {
+ const char *prog_name;
+ const char *expected_verifier_err_msg;
+ int expected_runtime_err;
+} kfunc_dynptr_tests[] = {
+ {"dynptr_type_not_supp",
+ "arg#0 pointer type STRUCT bpf_dynptr_kern points to unsupported dynamic pointer type", 0},
+ {"not_valid_dynptr",
+ "arg#0 pointer type STRUCT bpf_dynptr_kern must be valid and initialized", 0},
+ {"not_ptr_to_stack", "arg#0 pointer type STRUCT bpf_dynptr_kern not to stack", 0},
+ {"dynptr_data_null", NULL, -EBADMSG},
+};
+
+static bool kfunc_not_supported;
+
+static int libbpf_print_cb(enum libbpf_print_level level, const char *fmt,
+ va_list args)
+{
+ if (strcmp(fmt, "libbpf: extern (func ksym) '%s': not found in kernel or module BTFs\n"))
+ return 0;
+
+ if (strcmp(va_arg(args, char *), "bpf_verify_pkcs7_signature"))
+ return 0;
+
+ kfunc_not_supported = true;
+ return 0;
+}
+
+static void verify_fail(const char *prog_name, const char *expected_err_msg)
+{
+ struct test_kfunc_dynptr_param *skel;
+ LIBBPF_OPTS(bpf_object_open_opts, opts);
+ libbpf_print_fn_t old_print_cb;
+ struct bpf_program *prog;
+ int err;
+
+ opts.kernel_log_buf = obj_log_buf;
+ opts.kernel_log_size = log_buf_sz;
+ opts.kernel_log_level = 1;
+
+ skel = test_kfunc_dynptr_param__open_opts(&opts);
+ if (!ASSERT_OK_PTR(skel, "test_kfunc_dynptr_param__open_opts"))
+ goto cleanup;
+
+ prog = bpf_object__find_program_by_name(skel->obj, prog_name);
+ if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
+ goto cleanup;
+
+ bpf_program__set_autoload(prog, true);
+
+ bpf_map__set_max_entries(skel->maps.ringbuf, getpagesize());
+
+ kfunc_not_supported = false;
+
+ old_print_cb = libbpf_set_print(libbpf_print_cb);
+ err = test_kfunc_dynptr_param__load(skel);
+ libbpf_set_print(old_print_cb);
+
+ if (err < 0 && kfunc_not_supported) {
+ fprintf(stderr,
+ "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not supported\n",
+ __func__);
+ test__skip();
+ goto cleanup;
+ }
+
+ if (!ASSERT_ERR(err, "unexpected load success"))
+ goto cleanup;
+
+ if (!ASSERT_OK_PTR(strstr(obj_log_buf, expected_err_msg), "expected_err_msg")) {
+ fprintf(stderr, "Expected err_msg: %s\n", expected_err_msg);
+ fprintf(stderr, "Verifier output: %s\n", obj_log_buf);
+ }
+
+cleanup:
+ test_kfunc_dynptr_param__destroy(skel);
+}
+
+static void verify_success(const char *prog_name, int expected_runtime_err)
+{
+ struct test_kfunc_dynptr_param *skel;
+ libbpf_print_fn_t old_print_cb;
+ struct bpf_program *prog;
+ struct bpf_link *link;
+ __u32 next_id;
+ int err;
+
+ skel = test_kfunc_dynptr_param__open();
+ if (!ASSERT_OK_PTR(skel, "test_kfunc_dynptr_param__open"))
+ return;
+
+ skel->bss->pid = getpid();
+
+ bpf_map__set_max_entries(skel->maps.ringbuf, getpagesize());
+
+ kfunc_not_supported = false;
+
+ old_print_cb = libbpf_set_print(libbpf_print_cb);
+ err = test_kfunc_dynptr_param__load(skel);
+ libbpf_set_print(old_print_cb);
+
+ if (err < 0 && kfunc_not_supported) {
+ fprintf(stderr,
+ "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not supported\n",
+ __func__);
+ test__skip();
+ goto cleanup;
+ }
+
+ if (!ASSERT_OK(err, "test_kfunc_dynptr_param__load"))
+ goto cleanup;
+
+ prog = bpf_object__find_program_by_name(skel->obj, prog_name);
+ if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name"))
+ goto cleanup;
+
+ link = bpf_program__attach(prog);
+ if (!ASSERT_OK_PTR(link, "bpf_program__attach"))
+ goto cleanup;
+
+ err = bpf_prog_get_next_id(0, &next_id);
+
+ bpf_link__destroy(link);
+
+ if (!ASSERT_OK(err, "bpf_prog_get_next_id"))
+ goto cleanup;
+
+ ASSERT_EQ(skel->bss->err, expected_runtime_err, "err");
+
+cleanup:
+ test_kfunc_dynptr_param__destroy(skel);
+}
+
+void test_kfunc_dynptr_param(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(kfunc_dynptr_tests); i++) {
+ if (!test__start_subtest(kfunc_dynptr_tests[i].prog_name))
+ continue;
+
+ if (kfunc_dynptr_tests[i].expected_verifier_err_msg)
+ verify_fail(kfunc_dynptr_tests[i].prog_name,
+ kfunc_dynptr_tests[i].expected_verifier_err_msg);
+ else
+ verify_success(kfunc_dynptr_tests[i].prog_name,
+ kfunc_dynptr_tests[i].expected_runtime_err);
+ }
+}
diff --git a/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
new file mode 100644
index 000000000000..d7d39ea009a7
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_kfunc_dynptr_param.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <[email protected]>
+ */
+
+#include "vmlinux.h"
+#include <errno.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct bpf_dynptr {
+ __u64 :64;
+ __u64 :64;
+} __attribute__((aligned(8)));
+
+extern struct bpf_key *bpf_lookup_system_key(__u64 id) __ksym;
+extern void bpf_key_put(struct bpf_key *key) __ksym;
+extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr,
+ struct bpf_dynptr *sig_ptr,
+ struct bpf_key *trusted_keyring) __ksym;
+
+struct {
+ __uint(type, BPF_MAP_TYPE_RINGBUF);
+} ringbuf SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, __u32);
+ __type(value, __u32);
+} array_map SEC(".maps");
+
+int err, pid;
+
+char _license[] SEC("license") = "GPL";
+
+SEC("?lsm.s/bpf")
+int BPF_PROG(dynptr_type_not_supp, int cmd, union bpf_attr *attr,
+ unsigned int size)
+{
+ char write_data[64] = "hello there, world!!";
+ struct bpf_dynptr ptr;
+
+ bpf_ringbuf_reserve_dynptr(&ringbuf, sizeof(write_data), 0, &ptr);
+
+ return bpf_verify_pkcs7_signature(&ptr, &ptr, NULL);
+}
+
+SEC("?lsm.s/bpf")
+int BPF_PROG(not_valid_dynptr, int cmd, union bpf_attr *attr, unsigned int size)
+{
+ unsigned long val;
+
+ return bpf_verify_pkcs7_signature((struct bpf_dynptr *)&val,
+ (struct bpf_dynptr *)&val, NULL);
+}
+
+SEC("?lsm.s/bpf")
+int BPF_PROG(not_ptr_to_stack, int cmd, union bpf_attr *attr, unsigned int size)
+{
+ unsigned long val;
+
+ return bpf_verify_pkcs7_signature((struct bpf_dynptr *)val,
+ (struct bpf_dynptr *)val, NULL);
+}
+
+SEC("lsm.s/bpf")
+int BPF_PROG(dynptr_data_null, int cmd, union bpf_attr *attr, unsigned int size)
+{
+ struct bpf_key *trusted_keyring;
+ struct bpf_dynptr ptr;
+ __u32 *value;
+ int ret, zero = 0;
+
+ if (bpf_get_current_pid_tgid() >> 32 != pid)
+ return 0;
+
+ value = bpf_map_lookup_elem(&array_map, &zero);
+ if (!value)
+ return 0;
+
+ /* Pass invalid flags. */
+ ret = bpf_dynptr_from_mem(value, sizeof(*value), 1, &ptr);
+ if (ret != -EINVAL)
+ return 0;
+
+ trusted_keyring = bpf_lookup_system_key(0);
+ if (!trusted_keyring)
+ return 0;
+
+ err = bpf_verify_pkcs7_signature(&ptr, &ptr, trusted_keyring);
+
+ bpf_key_put(trusted_keyring);
+
+ return 0;
+}
--
2.25.1
On Wed, 7 Sept 2022 at 17:00, Roberto Sassu
<[email protected]> wrote:
>
> From: Roberto Sassu <[email protected]>
>
> Add tests to ensure that only supported dynamic pointer types are accepted,
> that the passed argument is actually a dynamic pointer, that the passed
> argument is a pointer to the stack, and that bpf_verify_pkcs7_signature()
> correctly handles dynamic pointers with data set to NULL.
>
> The tests are currently in the deny list for s390x (JIT does not support
> calling kernel function).
>
> Signed-off-by: Roberto Sassu <[email protected]>
> ---
Just a minor nit: you could probably use invalid flags value other
than 1, since most likely the next valid flag value will be 1, which
will require changing this again. LGTM otherwise.
Acked-by: Kumar Kartikeya Dwivedi <[email protected]>