From patchwork Tue Aug 2 09:10:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Savkov X-Patchwork-Id: 12934415 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EFB03C19F29 for ; Tue, 2 Aug 2022 09:10:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236360AbiHBJKx (ORCPT ); Tue, 2 Aug 2022 05:10:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39050 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236265AbiHBJKp (ORCPT ); Tue, 2 Aug 2022 05:10:45 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 05E4111814 for ; Tue, 2 Aug 2022 02:10:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659431444; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8SOINSRv0lSmbOTTZ6/R5mAtck6H0iUHXeANGpWfrm4=; b=Rwa+qECW3zrXydRZm3Y/fVzrMMK3GVaZBkDk1UiaRuQELqfNlFXLgLEEYbWYvT4Xca2sWC tPsEBVW2jXKnzdn0f+DdIyaeJJG7Jc0wO6TEYXDjynBCv4b7a9vlSd9APhMdCR5uPzMXb/ nHYdxeTkdkc9wBY/RltIcOG+Zcrcl38= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-394-4WC0f5O5OXeUuFp1yppU3g-1; Tue, 02 Aug 2022 05:10:33 -0400 X-MC-Unique: 4WC0f5O5OXeUuFp1yppU3g-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C82AF2801761; Tue, 2 Aug 2022 09:10:32 +0000 (UTC) Received: from shodan.usersys.redhat.com (unknown [10.43.17.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 86E6C1121314; Tue, 2 Aug 2022 09:10:32 +0000 (UTC) Received: by shodan.usersys.redhat.com (Postfix, from userid 1000) id 81A8C1C0151; Tue, 2 Aug 2022 11:10:31 +0200 (CEST) From: Artem Savkov To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , bpf@vger.kernel.org, netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Andrea Arcangeli , Daniel Vacek , Jiri Olsa , Song Liu , Daniel Xu , Artem Savkov Subject: [PATCH bpf-next v2 1/3] bpf: add destructive kfunc flag Date: Tue, 2 Aug 2022 11:10:28 +0200 Message-Id: <20220802091030.3742334-2-asavkov@redhat.com> In-Reply-To: <20220802091030.3742334-1-asavkov@redhat.com> References: <20220802091030.3742334-1-asavkov@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add KF_DESTRUCTIVE flag for destructive functions. Functions with this flag set will require CAP_SYS_BOOT capabilities. Signed-off-by: Artem Savkov --- include/linux/btf.h | 1 + kernel/bpf/verifier.c | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/include/linux/btf.h b/include/linux/btf.h index cdb376d53238..51a0961c84e3 100644 --- a/include/linux/btf.h +++ b/include/linux/btf.h @@ -49,6 +49,7 @@ * for this case. */ #define KF_TRUSTED_ARGS (1 << 4) /* kfunc only takes trusted pointer arguments */ +#define KF_DESTRUCTIVE (1 << 5) /* kfunc performs destructive actions */ struct btf; struct btf_member; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 096fdac70165..e52ca1631d3f 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -7584,6 +7584,11 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, func_name); return -EACCES; } + if (*kfunc_flags & KF_DESTRUCTIVE && !capable(CAP_SYS_BOOT)) { + verbose(env, "destructive kfunc calls require CAP_SYS_BOOT capabilities\n"); + return -EACCES; + } + acq = *kfunc_flags & KF_ACQUIRE; /* Check the arguments */ From patchwork Tue Aug 2 09:10:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Savkov X-Patchwork-Id: 12934414 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11987C00140 for ; Tue, 2 Aug 2022 09:10:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236332AbiHBJKw (ORCPT ); Tue, 2 Aug 2022 05:10:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236146AbiHBJKj (ORCPT ); Tue, 2 Aug 2022 05:10:39 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A0505167E0 for ; Tue, 2 Aug 2022 02:10:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659431437; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TwBb9lEjHn3drMZDMM/zYMhet6xNvu6dn9eorLLxNfM=; b=U6sRuAIE2frv7dC4yJejAIJMIyMBI5YcF3PvW8VCboOgb099OQYO3fEd25MIH4wfubXOoy JNj/fhfYS0pUVl/T79t5w6Qh11x4Titzyn+G/KZvGknJ6ddjFgYpCt2RYrwYjzvA1o9xSw rnB36ObcnKRTxog11NSuFBIZpGf/16Q= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-625-Glkrt58cPx6Frhho0-hlzA-1; Tue, 02 Aug 2022 05:10:33 -0400 X-MC-Unique: Glkrt58cPx6Frhho0-hlzA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id C87AA3802B82; Tue, 2 Aug 2022 09:10:32 +0000 (UTC) Received: from shodan.usersys.redhat.com (unknown [10.43.17.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 86DD990A04; Tue, 2 Aug 2022 09:10:32 +0000 (UTC) Received: by shodan.usersys.redhat.com (Postfix, from userid 1000) id 8C4521C0291; Tue, 2 Aug 2022 11:10:31 +0200 (CEST) From: Artem Savkov To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , bpf@vger.kernel.org, netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Andrea Arcangeli , Daniel Vacek , Jiri Olsa , Song Liu , Daniel Xu , Artem Savkov Subject: [PATCH bpf-next v2 2/3] bpf: export crash_kexec() as destructive kfunc Date: Tue, 2 Aug 2022 11:10:29 +0200 Message-Id: <20220802091030.3742334-3-asavkov@redhat.com> In-Reply-To: <20220802091030.3742334-1-asavkov@redhat.com> References: <20220802091030.3742334-1-asavkov@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Allow properly marked bpf programs to call crash_kexec(). Signed-off-by: Artem Savkov --- kernel/kexec_core.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index 4d34c78334ce..9259ea3bd693 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -39,6 +39,8 @@ #include #include #include +#include +#include #include #include @@ -1238,3 +1240,22 @@ void __weak arch_kexec_protect_crashkres(void) void __weak arch_kexec_unprotect_crashkres(void) {} + +#ifdef CONFIG_DEBUG_INFO_BTF_MODULES +BTF_SET8_START(kexec_btf_ids) +BTF_ID_FLAGS(func, crash_kexec, KF_DESTRUCTIVE) +BTF_SET8_END(kexec_btf_ids) + +static const struct btf_kfunc_id_set kexec_kfunc_set = { + .owner = THIS_MODULE, + .set = &kexec_btf_ids, +}; + +static int __init crash_kfunc_init(void) +{ + register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, &kexec_kfunc_set); + return 0; +} + +subsys_initcall(crash_kfunc_init); +#endif From patchwork Tue Aug 2 09:10:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Artem Savkov X-Patchwork-Id: 12934413 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD42AC00140 for ; Tue, 2 Aug 2022 09:10:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236183AbiHBJKu (ORCPT ); Tue, 2 Aug 2022 05:10:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236069AbiHBJKj (ORCPT ); Tue, 2 Aug 2022 05:10:39 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id C60E315A3D for ; Tue, 2 Aug 2022 02:10:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1659431436; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=W9d+NTIs3kSzvnOzgM/E/JlVOMe/5l6psOH5nCcWDRA=; b=HUa2aMnCY44GMTxtLDCdrtTuo8dQ5Ol5RjEwX9GLbm20R+QKZm89NP1n8JBlF08AnGdCRa Of6jaarHnAPJZvrkNE+OUyri2EbgV8klOk0sM8LLPrvcIfZq5rimlpJFPuGw8sjjR2OEy6 kFrl68JU0j1qQReXkdz2XsiI2aVmpnE= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-625-ufCtfNzNO9-Oll4xmPlOLg-1; Tue, 02 Aug 2022 05:10:33 -0400 X-MC-Unique: ufCtfNzNO9-Oll4xmPlOLg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id CBF9B85A586; Tue, 2 Aug 2022 09:10:32 +0000 (UTC) Received: from shodan.usersys.redhat.com (unknown [10.43.17.22]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 86DCC2166B26; Tue, 2 Aug 2022 09:10:32 +0000 (UTC) Received: by shodan.usersys.redhat.com (Postfix, from userid 1000) id 908F41C02B9; Tue, 2 Aug 2022 11:10:31 +0200 (CEST) From: Artem Savkov To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , bpf@vger.kernel.org, netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Andrea Arcangeli , Daniel Vacek , Jiri Olsa , Song Liu , Daniel Xu , Artem Savkov Subject: [PATCH bpf-next v2 3/3] selftests/bpf: add destructive kfunc test Date: Tue, 2 Aug 2022 11:10:30 +0200 Message-Id: <20220802091030.3742334-4-asavkov@redhat.com> In-Reply-To: <20220802091030.3742334-1-asavkov@redhat.com> References: <20220802091030.3742334-1-asavkov@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add a test checking that programs calling destructive kfuncs can only do so if they have CAP_SYS_BOOT capabilities. Signed-off-by: Artem Savkov --- net/bpf/test_run.c | 5 +++ .../selftests/bpf/prog_tests/kfunc_call.c | 36 +++++++++++++++++++ .../bpf/progs/kfunc_call_destructive.c | 14 ++++++++ 3 files changed, 55 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/kfunc_call_destructive.c diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c index cbc9cd5058cb..afa7125252f6 100644 --- a/net/bpf/test_run.c +++ b/net/bpf/test_run.c @@ -695,6 +695,10 @@ noinline void bpf_kfunc_call_test_ref(struct prog_test_ref_kfunc *p) { } +noinline void bpf_kfunc_call_test_destructive(void) +{ +} + __diag_pop(); ALLOW_ERROR_INJECTION(bpf_modify_return_test, ERRNO); @@ -719,6 +723,7 @@ BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_pass1) BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail1) BTF_ID_FLAGS(func, bpf_kfunc_call_test_mem_len_fail2) BTF_ID_FLAGS(func, bpf_kfunc_call_test_ref, KF_TRUSTED_ARGS) +BTF_ID_FLAGS(func, bpf_kfunc_call_test_destructive, KF_DESTRUCTIVE) BTF_SET8_END(test_sk_check_kfunc_ids) static void *bpf_test_init(const union bpf_attr *kattr, u32 user_size, diff --git a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c index c00eb974eb85..351fafa006fb 100644 --- a/tools/testing/selftests/bpf/prog_tests/kfunc_call.c +++ b/tools/testing/selftests/bpf/prog_tests/kfunc_call.c @@ -5,6 +5,9 @@ #include "kfunc_call_test.lskel.h" #include "kfunc_call_test_subprog.skel.h" #include "kfunc_call_test_subprog.lskel.h" +#include "kfunc_call_destructive.skel.h" + +#include "cap_helpers.h" static void test_main(void) { @@ -86,6 +89,36 @@ static void test_subprog_lskel(void) kfunc_call_test_subprog_lskel__destroy(skel); } +static int test_destructive_open_and_load(void) +{ + struct kfunc_call_destructive *skel; + int err; + + skel = kfunc_call_destructive__open(); + if (!ASSERT_OK_PTR(skel, "prog_open")) + return -1; + + err = kfunc_call_destructive__load(skel); + + kfunc_call_destructive__destroy(skel); + + return err; +} + +static void test_destructive(void) +{ + __u64 save_caps = 0; + + ASSERT_OK(test_destructive_open_and_load(), "succesful_load"); + + if (!ASSERT_OK(cap_disable_effective(1ULL << CAP_SYS_BOOT, &save_caps), "drop_caps")) + return; + + ASSERT_EQ(test_destructive_open_and_load(), -13, "no_caps_failure"); + + cap_enable_effective(save_caps, NULL); +} + void test_kfunc_call(void) { if (test__start_subtest("main")) @@ -96,4 +129,7 @@ void test_kfunc_call(void) if (test__start_subtest("subprog_lskel")) test_subprog_lskel(); + + if (test__start_subtest("destructive")) + test_destructive(); } diff --git a/tools/testing/selftests/bpf/progs/kfunc_call_destructive.c b/tools/testing/selftests/bpf/progs/kfunc_call_destructive.c new file mode 100644 index 000000000000..767472bc5a97 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/kfunc_call_destructive.c @@ -0,0 +1,14 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include + +extern void bpf_kfunc_call_test_destructive(void) __ksym; + +SEC("tc") +int kfunc_destructive_test(void) +{ + bpf_kfunc_call_test_destructive(); + return 0; +} + +char _license[] SEC("license") = "GPL";