linux-kernel - Re: [PATCH v17 11/12] selftests/bpf: Add test for bpf_verify_pkcs7

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CACYkzJ7uraUdmGV9gMmTZs1OMb_3Q2DttoaxU-irmrXFudOweQ@mail.gmail.com>
Date:   Thu, 15 Sep 2022 17:11:39 +0100
From:   KP Singh <kpsingh@...nel.org>
To:     Roberto Sassu <roberto.sassu@...weicloud.com>
Cc:     ast@...nel.org, daniel@...earbox.net, andrii@...nel.org,
        martin.lau@...ux.dev, song@...nel.org, yhs@...com,
        john.fastabend@...il.com, sdf@...gle.com, haoluo@...gle.com,
        jolsa@...nel.org, mykolal@...com, dhowells@...hat.com,
        jarkko@...nel.org, rostedt@...dmis.org, mingo@...hat.com,
        paul@...l-moore.com, jmorris@...ei.org, serge@...lyn.com,
        shuah@...nel.org, bpf@...r.kernel.org, keyrings@...r.kernel.org,
        linux-security-module@...r.kernel.org,
        linux-kselftest@...r.kernel.org, linux-kernel@...r.kernel.org,
        deso@...teo.net, memxor@...il.com,
        Roberto Sassu <roberto.sassu@...wei.com>,
        Joanne Koong <joannelkoong@...il.com>
Subject: Re: [PATCH v17 11/12] selftests/bpf: Add test for bpf_verify_pkcs7_signature()
 kfunc

On Fri, Sep 9, 2022 at 1:10 PM Roberto Sassu
<roberto.sassu@...weicloud.com> wrote:
>
> From: Roberto Sassu <roberto.sassu@...wei.com>
>

[...]

> +}
> diff --git a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
> new file mode 100644
> index 000000000000..4ceab545d99a
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
> @@ -0,0 +1,100 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +/*
> + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
> + *
> + * Author: Roberto Sassu <roberto.sassu@...wei.com>
> + */
> +
> +#include "vmlinux.h"
> +#include <errno.h>
> +#include <bpf/bpf_helpers.h>
> +#include <bpf/bpf_tracing.h>
> +
> +#define MAX_DATA_SIZE (1024 * 1024)
> +#define MAX_SIG_SIZE 1024
> +
> +typedef __u8 u8;
> +typedef __u16 u16;
> +typedef __u32 u32;
> +typedef __u64 u64;

I think you can avoid this and just use u32 and u64 directly.

> +
> +struct bpf_dynptr {
> +       __u64 :64;
> +       __u64 :64;
> +} __attribute__((aligned(8)));
> +

I think you are doing this because including the uapi headers causes
type conflicts.
This does happen quite often. What do other folks think about doing
something like

#define DYNPTR(x) ((void *)x)

It seems like this will be an issue anytime we use the helpers with
vmlinux.h and users
will always have to define this type in their tests.

- KP

> +extern struct bpf_key *bpf_lookup_user_key(__u32 serial, __u64 flags) __ksym;
> +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;
> +
> +u32 monitored_pid;
> +u32 user_keyring_serial;
> +u64 system_keyring_id;
> +
> +struct data {
> +       u8 data[MAX_DATA_SIZE];
> +       u32 data_len;
> +       u8 sig[MAX_SIG_SIZE];
> +       u32 sig_len;
> +};
> +
> +struct {
> +       __uint(type, BPF_MAP_TYPE_ARRAY);
> +       __uint(max_entries, 1);
> +       __type(key, __u32);
> +       __type(value, struct data);
> +} data_input SEC(".maps");
> +
> +char _license[] SEC("license") = "GPL";
> +
> +SEC("lsm.s/bpf")
> +int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size)
> +{
> +       struct bpf_dynptr data_ptr, sig_ptr;
> +       struct data *data_val;
> +       struct bpf_key *trusted_keyring;
> +       u32 pid;
> +       u64 value;
> +       int ret, zero = 0;
> +
> +       pid = bpf_get_current_pid_tgid() >> 32;
> +       if (pid != monitored_pid)
> +               return 0;
> +
> +       data_val = bpf_map_lookup_elem(&data_input, &zero);
> +       if (!data_val)
> +               return 0;
> +
> +       bpf_probe_read(&value, sizeof(value), &attr->value);
> +
> +       bpf_copy_from_user(data_val, sizeof(struct data),
>

[...]

> --
> 2.25.1
>