From patchwork Fri Aug 12 10:18:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942125 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 F25EDC25B0F for ; Fri, 12 Aug 2022 10:20:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238381AbiHLKUA (ORCPT ); Fri, 12 Aug 2022 06:20:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47606 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231271AbiHLKT5 (ORCPT ); Fri, 12 Aug 2022 06:19:57 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6EBAABD54; Fri, 12 Aug 2022 03:19:56 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M406D3SJvz67Xgw; Fri, 12 Aug 2022 18:19:48 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:19:53 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v11 1/9] bpf: Allow kfuncs to be used in LSM programs Date: Fri, 12 Aug 2022 12:18:54 +0200 Message-ID: <20220812101902.2846182-2-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: From: KP Singh In preparation for the addition of new kfuncs, allow kfuncs defined in the tracing subsystem to be used in LSM programs by mapping the LSM program type to the TRACING hook. Signed-off-by: KP Singh Signed-off-by: Roberto Sassu --- kernel/bpf/btf.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 903719b89238..e49b3b6d48ad 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -7243,6 +7243,7 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) case BPF_PROG_TYPE_STRUCT_OPS: return BTF_KFUNC_HOOK_STRUCT_OPS; case BPF_PROG_TYPE_TRACING: + case BPF_PROG_TYPE_LSM: return BTF_KFUNC_HOOK_TRACING; case BPF_PROG_TYPE_SYSCALL: return BTF_KFUNC_HOOK_SYSCALL; From patchwork Fri Aug 12 10:18:55 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942128 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 29DF0C32763 for ; Fri, 12 Aug 2022 10:20:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238397AbiHLKUB (ORCPT ); Fri, 12 Aug 2022 06:20:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47624 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237236AbiHLKT7 (ORCPT ); Fri, 12 Aug 2022 06:19:59 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 35F00AB4C6; Fri, 12 Aug 2022 03:19:58 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M4036015Jz688p4; Fri, 12 Aug 2022 18:17:06 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:19:54 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu , Joanne Koong Subject: [PATCH v11 2/9] btf: Handle dynamic pointer parameter in kfuncs Date: Fri, 12 Aug 2022 12:18:55 +0200 Message-ID: <20220812101902.2846182-3-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Allow the bpf_dynptr_kern parameter to be specified in kfuncs. Also, ensure that the dynamic pointer is valid and initialized. Cc: Joanne Koong Signed-off-by: Roberto Sassu --- include/linux/bpf_verifier.h | 3 +++ kernel/bpf/btf.c | 22 ++++++++++++++++++++++ kernel/bpf/verifier.c | 4 ++-- 3 files changed, 27 insertions(+), 2 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index 2e3bad8640dc..55876fbdbae2 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -560,6 +560,9 @@ int check_kfunc_mem_size_reg(struct bpf_verifier_env *env, struct bpf_reg_state u32 regno); int check_mem_reg(struct bpf_verifier_env *env, struct bpf_reg_state *reg, u32 regno, u32 mem_size); +bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, + struct bpf_reg_state *reg, + enum bpf_arg_type arg_type); /* this lives here instead of in bpf.h because it needs to dereference tgt_prog */ static inline u64 bpf_trampoline_compute_key(const struct bpf_prog *tgt_prog, diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index e49b3b6d48ad..86e63f2ee5da 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -195,6 +195,10 @@ i < btf_type_vlen(struct_type); \ i++, member++) +#define stringify_struct(x) \ + ({ BUILD_BUG_ON(sizeof(struct x) < 0); \ + __stringify(x); }) + DEFINE_IDR(btf_idr); DEFINE_SPINLOCK(btf_idr_lock); @@ -6362,15 +6366,20 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, if (is_kfunc) { bool arg_mem_size = i + 1 < nargs && is_kfunc_arg_mem_size(btf, &args[i + 1], ®s[regno + 1]); + bool arg_dynptr = btf_type_is_struct(ref_t) && + !strcmp(ref_tname, + stringify_struct(bpf_dynptr_kern)); /* Permit pointer to mem, but only when argument * type is pointer to scalar, or struct composed * (recursively) of scalars. * When arg_mem_size is true, the pointer can be * void *. + * Also permit initialized dynamic pointers. */ if (!btf_type_is_scalar(ref_t) && !__btf_type_is_scalar_struct(log, btf, ref_t, 0) && + !arg_dynptr && (arg_mem_size ? !btf_type_is_void(ref_t) : 1)) { bpf_log(log, "arg#%d pointer type %s %s must point to %sscalar, or struct with scalar\n", @@ -6378,6 +6387,19 @@ static int btf_check_func_arg_match(struct bpf_verifier_env *env, return -EINVAL; } + if (arg_dynptr) { + if (!is_dynptr_reg_valid_init(env, reg, + ARG_PTR_TO_DYNPTR)) { + bpf_log(log, + "arg#%d pointer type %s %s must be initialized\n", + i, btf_type_str(ref_t), + ref_tname); + return -EINVAL; + } + + continue; + } + /* Check for mem, len pair */ if (arg_mem_size) { if (check_kfunc_mem_size_reg(env, ®s[regno + 1], regno + 1)) { diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 2c1f8069f7b7..aa834e7bb296 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -779,8 +779,8 @@ static bool is_dynptr_reg_valid_uninit(struct bpf_verifier_env *env, struct bpf_ return true; } -static bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, struct bpf_reg_state *reg, - enum bpf_arg_type arg_type) +bool is_dynptr_reg_valid_init(struct bpf_verifier_env *env, struct bpf_reg_state *reg, + enum bpf_arg_type arg_type) { struct bpf_func_state *state = func(env, reg); int spi = get_spi(reg->off); From patchwork Fri Aug 12 10:18:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942127 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 A69E0C282E7 for ; Fri, 12 Aug 2022 10:20:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238422AbiHLKUC (ORCPT ); Fri, 12 Aug 2022 06:20:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47642 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237995AbiHLKUA (ORCPT ); Fri, 12 Aug 2022 06:20:00 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A75D7AB4C6; Fri, 12 Aug 2022 03:19:59 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M406H2pqXz682NF; Fri, 12 Aug 2022 18:19:51 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:19:56 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu , Joanne Koong Subject: [PATCH v11 3/9] bpf: Export bpf_dynptr_get_size() Date: Fri, 12 Aug 2022 12:18:56 +0200 Message-ID: <20220812101902.2846182-4-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Export bpf_dynptr_get_size(), so that kernel code dealing with eBPF dynamic pointers can obtain the real size of data carried by this data structure. Reviewed-by: Joanne Koong Signed-off-by: Roberto Sassu --- include/linux/bpf.h | 1 + kernel/bpf/helpers.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a627a02cf8ab..a82f8c559ae2 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2563,6 +2563,7 @@ void bpf_dynptr_init(struct bpf_dynptr_kern *ptr, void *data, enum bpf_dynptr_type type, u32 offset, u32 size); void bpf_dynptr_set_null(struct bpf_dynptr_kern *ptr); int bpf_dynptr_check_size(u32 size); +u32 bpf_dynptr_get_size(struct bpf_dynptr_kern *ptr); #ifdef CONFIG_BPF_LSM void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype); diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 3c1b9bbcf971..e4637ccb3016 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1442,7 +1442,7 @@ static void bpf_dynptr_set_type(struct bpf_dynptr_kern *ptr, enum bpf_dynptr_typ ptr->size |= type << DYNPTR_TYPE_SHIFT; } -static u32 bpf_dynptr_get_size(struct bpf_dynptr_kern *ptr) +u32 bpf_dynptr_get_size(struct bpf_dynptr_kern *ptr) { return ptr->size & DYNPTR_SIZE_MASK; } From patchwork Fri Aug 12 10:18:57 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942129 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 156D3C2BB43 for ; Fri, 12 Aug 2022 10:20:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238425AbiHLKUD (ORCPT ); Fri, 12 Aug 2022 06:20:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47688 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238415AbiHLKUC (ORCPT ); Fri, 12 Aug 2022 06:20:02 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1118AB4C6; Fri, 12 Aug 2022 03:20:00 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M40386BLgz688sr; Fri, 12 Aug 2022 18:17:08 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:19:57 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v11 4/9] KEYS: Move KEY_LOOKUP_ to include/linux/key.h Date: Fri, 12 Aug 2022 12:18:57 +0200 Message-ID: <20220812101902.2846182-5-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100001.china.huawei.com (7.191.160.183) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: In preparation for the patch that introduces the bpf_lookup_user_key() eBPF kfunc, move KEY_LOOKUP_ definitions to include/linux/key.h, to be able to validate the kfunc parameters. Also, introduce key_lookup_flags_check() directly in include/linux/key.h, to reduce the risk that the check is not in sync with currently defined flags. Signed-off-by: Roberto Sassu Reviewed-by: KP Singh --- include/linux/key.h | 11 +++++++++++ security/keys/internal.h | 2 -- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/include/linux/key.h b/include/linux/key.h index 7febc4881363..b5bbae77a9e7 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -88,6 +88,17 @@ enum key_need_perm { KEY_DEFER_PERM_CHECK, /* Special: permission check is deferred */ }; +#define KEY_LOOKUP_CREATE 0x01 +#define KEY_LOOKUP_PARTIAL 0x02 + +static inline int key_lookup_flags_check(u64 flags) +{ + if (flags & ~(KEY_LOOKUP_CREATE | KEY_LOOKUP_PARTIAL)) + return -EINVAL; + + return 0; +} + struct seq_file; struct user_struct; struct signal_struct; diff --git a/security/keys/internal.h b/security/keys/internal.h index 9b9cf3b6fcbb..3c1e7122076b 100644 --- a/security/keys/internal.h +++ b/security/keys/internal.h @@ -165,8 +165,6 @@ extern struct key *request_key_and_link(struct key_type *type, extern bool lookup_user_key_possessed(const struct key *key, const struct key_match_data *match_data); -#define KEY_LOOKUP_CREATE 0x01 -#define KEY_LOOKUP_PARTIAL 0x02 extern long join_session_keyring(const char *name); extern void key_change_session_keyring(struct callback_head *twork); From patchwork Fri Aug 12 10:18:58 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942133 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 3BEE2C2BB47 for ; Fri, 12 Aug 2022 10:21:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237559AbiHLKVg (ORCPT ); Fri, 12 Aug 2022 06:21:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50348 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238811AbiHLKVR (ORCPT ); Fri, 12 Aug 2022 06:21:17 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3564C6C125; Fri, 12 Aug 2022 03:21:16 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M407m092Bz67Xgw; Fri, 12 Aug 2022 18:21:08 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:21:12 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v11 5/9] bpf: Add bpf_lookup_*_key() and bpf_key_put() kfuncs Date: Fri, 12 Aug 2022 12:18:58 +0200 Message-ID: <20220812101902.2846182-6-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Add the bpf_lookup_user_key(), bpf_lookup_system_key() and bpf_key_put() kfuncs, to respectively search a key with a given key handle serial number and flags, obtain a key from a pre-determined ID defined in include/linux/verification.h, and cleanup. Introduce system_keyring_id_check() to validate the keyring ID parameter of bpf_lookup_system_key(). Signed-off-by: Roberto Sassu --- include/linux/bpf.h | 6 ++ include/linux/verification.h | 8 +++ kernel/trace/bpf_trace.c | 135 +++++++++++++++++++++++++++++++++++ 3 files changed, 149 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a82f8c559ae2..d415e5e97551 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2573,4 +2573,10 @@ static inline void bpf_cgroup_atype_get(u32 attach_btf_id, int cgroup_atype) {} static inline void bpf_cgroup_atype_put(int cgroup_atype) {} #endif /* CONFIG_BPF_LSM */ +#ifdef CONFIG_KEYS +struct bpf_key { + struct key *key; + bool has_ref; +}; +#endif /* CONFIG_KEYS */ #endif /* _LINUX_BPF_H */ diff --git a/include/linux/verification.h b/include/linux/verification.h index a655923335ae..f34e50ebcf60 100644 --- a/include/linux/verification.h +++ b/include/linux/verification.h @@ -17,6 +17,14 @@ #define VERIFY_USE_SECONDARY_KEYRING ((struct key *)1UL) #define VERIFY_USE_PLATFORM_KEYRING ((struct key *)2UL) +static inline int system_keyring_id_check(u64 id) +{ + if (id > (unsigned long)VERIFY_USE_PLATFORM_KEYRING) + return -EINVAL; + + return 0; +} + /* * The use to which an asymmetric key is being put. */ diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 68e5cdd24cef..dfea85c7f4f0 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -20,6 +20,8 @@ #include #include #include +#include +#include #include @@ -1181,6 +1183,139 @@ static const struct bpf_func_proto bpf_get_func_arg_cnt_proto = { .arg1_type = ARG_PTR_TO_CTX, }; +#ifdef CONFIG_KEYS +__diag_push(); +__diag_ignore_all("-Wmissing-prototypes", + "kfuncs which will be used in BPF programs"); + +/** + * bpf_lookup_user_key - lookup a key by its serial + * @serial: key handle serial number + * @flags: lookup-specific flags + * + * Search a key with a given *serial* and the provided *flags*. + * If found, increment the reference count of the key by one, and + * return it in the bpf_key structure. + * + * The bpf_key structure must be passed to bpf_key_put() when done + * with it, so that the key reference count is decremented and the + * bpf_key structure is freed. + * + * Permission checks are deferred to the time the key is used by + * one of the available key-specific kfuncs. + * + * Set *flags* with KEY_LOOKUP_CREATE, to attempt creating a requested + * special keyring (e.g. session keyring), if it doesn't yet exist. + * Set *flags* with KEY_LOOKUP_PARTIAL, to lookup a key without waiting + * for the key construction, and to retrieve uninstantiated keys (keys + * without data attached to them). + * + * Return: a bpf_key pointer with a valid key pointer if the key is found, a + * NULL pointer otherwise. + */ +struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) +{ + key_ref_t key_ref; + struct bpf_key *bkey; + + if (key_lookup_flags_check(flags) < 0) + return NULL; + + /* + * Permission check is deferred until the key is used, as the + * intent of the caller is unknown here. + */ + key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK); + if (IS_ERR(key_ref)) + return NULL; + + bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); + if (!bkey) { + key_put(key_ref_to_ptr(key_ref)); + return NULL; + } + + bkey->key = key_ref_to_ptr(key_ref); + bkey->has_ref = true; + + return bkey; +} + +/** + * bpf_lookup_system_key - lookup a key by a system-defined ID + * @id: key ID + * + * Obtain a bpf_key structure with a key pointer set to the passed key ID. + * The key pointer is marked as invalid, to prevent bpf_key_put() from + * attempting to decrement the key reference count on that pointer. The key + * pointer set in such way is currently understood only by + * verify_pkcs7_signature(). + * + * Set *id* to one of the values defined in include/linux/verification.h: + * 0 for the primary keyring (immutable keyring of system keys); + * VERIFY_USE_SECONDARY_KEYRING for both the primary and secondary keyring + * (where keys can be added only if they are vouched for by existing keys + * in those keyrings); VERIFY_USE_PLATFORM_KEYRING for the platform + * keyring (primarily used by the integrity subsystem to verify a kexec'ed + * kerned image and, possibly, the initramfs signature). + * + * Return: a bpf_key pointer with an invalid key pointer set from the + * pre-determined ID on success, a NULL pointer otherwise + */ +struct bpf_key *bpf_lookup_system_key(u64 id) +{ + struct bpf_key *bkey; + + if (system_keyring_id_check(id) < 0) + return NULL; + + bkey = kmalloc(sizeof(*bkey), GFP_ATOMIC); + if (!bkey) + return NULL; + + bkey->key = (struct key *)(unsigned long)id; + bkey->has_ref = false; + + return bkey; +} + +/** + * bpf_key_put - decrement key reference count if key is valid and free bpf_key + * @bkey: bpf_key structure + * + * Decrement the reference count of the key inside *bkey*, if the pointer + * is valid, and free *bkey*. + */ +void bpf_key_put(struct bpf_key *bkey) +{ + if (bkey->has_ref) + key_put(bkey->key); + + kfree(bkey); +} + +__diag_pop(); + +BTF_SET8_START(key_sig_kfunc_set) +BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) +BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) +BTF_SET8_END(key_sig_kfunc_set) + +static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { + .owner = THIS_MODULE, + .set = &key_sig_kfunc_set, +}; + +static int __init bpf_key_sig_kfuncs_init(void) +{ + return register_btf_kfunc_id_set(BPF_PROG_TYPE_TRACING, + &bpf_key_sig_kfunc_set); +} + +late_initcall(bpf_key_sig_kfuncs_init); +#endif /* CONFIG_KEYS */ + static const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { From patchwork Fri Aug 12 10:18:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942131 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 41D7CC32764 for ; Fri, 12 Aug 2022 10:21:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238502AbiHLKVc (ORCPT ); Fri, 12 Aug 2022 06:21:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238814AbiHLKVS (ORCPT ); Fri, 12 Aug 2022 06:21:18 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF3456C135; Fri, 12 Aug 2022 03:21:17 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M407n40cTz67bjw; Fri, 12 Aug 2022 18:21:09 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:21:14 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v11 6/9] bpf: Add bpf_verify_pkcs7_signature() kfunc Date: Fri, 12 Aug 2022 12:18:59 +0200 Message-ID: <20220812101902.2846182-7-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Add the bpf_verify_pkcs7_signature() kfunc, to give eBPF security modules the ability to check the validity of a signature against supplied data, by using user-provided or system-provided keys as trust anchor. The new kfunc makes it possible to enforce mandatory policies, as eBPF programs might be allowed to make security decisions only based on data sources the system administrator approves. The caller should provide the data to be verified and the signature as eBPF dynamic pointers (to minimize the number of parameters) and a bpf_key structure containing a reference to the keyring with keys trusted for signature verification, obtained from bpf_lookup_user_key() or bpf_lookup_system_key(). For bpf_key structures obtained from the former lookup function, bpf_verify_pkcs7_signature() completes the permission check deferred by that function by calling key_validate(). key_task_permission() is already called by the PKCS#7 code. Signed-off-by: Roberto Sassu Acked-by: KP Singh --- kernel/trace/bpf_trace.c | 45 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index dfea85c7f4f0..b1fb985ba1b3 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1294,12 +1294,57 @@ void bpf_key_put(struct bpf_key *bkey) kfree(bkey); } +#ifdef CONFIG_SYSTEM_DATA_VERIFICATION +/** + * bpf_verify_pkcs7_signature - verify a PKCS#7 signature + * @data_ptr: data to verify + * @sig_ptr: signature of the data + * @trusted_keyring: keyring with keys trusted for signature verification + * + * Verify the PKCS#7 signature *sig_ptr* against the supplied *data_ptr* + * with keys in a keyring referenced by *trusted_keyring*. + * + * Return: 0 on success, a negative value on error. + */ +int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, + struct bpf_dynptr_kern *sig_ptr, + struct bpf_key *trusted_keyring) +{ + int ret; + + if (trusted_keyring->has_ref) { + /* + * Do the permission check deferred in bpf_lookup_user_key(). + * See bpf_lookup_user_key() for more details. + * + * A call to key_task_permission() here would be redundant, as + * it is already done by keyring_search() called by + * find_asymmetric_key(). + */ + ret = key_validate(trusted_keyring->key); + if (ret < 0) + return ret; + } + + return verify_pkcs7_signature(data_ptr->data, + bpf_dynptr_get_size(data_ptr), + sig_ptr->data, + bpf_dynptr_get_size(sig_ptr), + trusted_keyring->key, + VERIFYING_UNSPECIFIED_SIGNATURE, NULL, + NULL); +} +#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */ + __diag_pop(); BTF_SET8_START(key_sig_kfunc_set) BTF_ID_FLAGS(func, bpf_lookup_user_key, KF_ACQUIRE | KF_RET_NULL | KF_SLEEPABLE) BTF_ID_FLAGS(func, bpf_lookup_system_key, KF_ACQUIRE | KF_RET_NULL) BTF_ID_FLAGS(func, bpf_key_put, KF_RELEASE) +#ifdef CONFIG_SYSTEM_DATA_VERIFICATION +BTF_ID_FLAGS(func, bpf_verify_pkcs7_signature, KF_SLEEPABLE) +#endif BTF_SET8_END(key_sig_kfunc_set) static const struct btf_kfunc_id_set bpf_key_sig_kfunc_set = { From patchwork Fri Aug 12 10:19:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942132 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 24D0DC282E7 for ; Fri, 12 Aug 2022 10:21:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238480AbiHLKVd (ORCPT ); Fri, 12 Aug 2022 06:21:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50490 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238821AbiHLKVU (ORCPT ); Fri, 12 Aug 2022 06:21:20 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3EA8874E3F; Fri, 12 Aug 2022 03:21:19 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.201]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M404g0z77z687qT; Fri, 12 Aug 2022 18:18:27 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:21:15 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v11 7/9] selftests/bpf: Add verifier tests for bpf_lookup_*_key() and bpf_key_put() Date: Fri, 12 Aug 2022 12:19:00 +0200 Message-ID: <20220812101902.2846182-8-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Add verifier tests for bpf_lookup_*_key() and bpf_key_put(), to ensure that acquired key references stored in the bpf_key structure are released, that a non-NULL bpf_key pointer is passed to bpf_key_put(), and that key references are not leaked. Also, slightly modify test_verifier.c, to find the BTF ID of the attach point for the LSM program type (currently, it is done only for TRACING). Signed-off-by: Roberto Sassu --- tools/testing/selftests/bpf/config | 1 + tools/testing/selftests/bpf/test_verifier.c | 3 +- .../selftests/bpf/verifier/ref_tracking.c | 139 ++++++++++++++++++ 3 files changed, 142 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index fabf0c014349..c99b196aa840 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -30,6 +30,7 @@ CONFIG_IPV6_GRE=y CONFIG_IPV6_SEG6_BPF=y CONFIG_IPV6_SIT=m CONFIG_IPV6_TUNNEL=y +CONFIG_KEYS=y CONFIG_LIRC=y CONFIG_LWTUNNEL=y CONFIG_MPLS=y diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index f9d553fbf68a..2dbcbf363c18 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -1498,7 +1498,8 @@ static void do_test_single(struct bpf_test *test, bool unpriv, opts.log_level = DEFAULT_LIBBPF_LOG_LEVEL; opts.prog_flags = pflags; - if (prog_type == BPF_PROG_TYPE_TRACING && test->kfunc) { + if ((prog_type == BPF_PROG_TYPE_TRACING || + prog_type == BPF_PROG_TYPE_LSM) && test->kfunc) { int attach_btf_id; attach_btf_id = libbpf_find_vmlinux_btf_id(test->kfunc, diff --git a/tools/testing/selftests/bpf/verifier/ref_tracking.c b/tools/testing/selftests/bpf/verifier/ref_tracking.c index 57a83d763ec1..f18ce867271f 100644 --- a/tools/testing/selftests/bpf/verifier/ref_tracking.c +++ b/tools/testing/selftests/bpf/verifier/ref_tracking.c @@ -84,6 +84,145 @@ .errstr = "Unreleased reference", .result = REJECT, }, +{ + "reference tracking: acquire/release user key reference", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .fixup_kfunc_btf_id = { + { "bpf_lookup_user_key", 2 }, + { "bpf_key_put", 5 }, + }, + .result = ACCEPT, +}, +{ + "reference tracking: acquire/release system key reference", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .fixup_kfunc_btf_id = { + { "bpf_lookup_system_key", 1 }, + { "bpf_key_put", 4 }, + }, + .result = ACCEPT, +}, +{ + "reference tracking: release user key reference without check", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "arg#0 pointer type STRUCT bpf_key must point to scalar, or struct with scalar", + .fixup_kfunc_btf_id = { + { "bpf_lookup_user_key", 2 }, + { "bpf_key_put", 4 }, + }, + .result = REJECT, +}, +{ + "reference tracking: release system key reference without check", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "arg#0 pointer type STRUCT bpf_key must point to scalar, or struct with scalar", + .fixup_kfunc_btf_id = { + { "bpf_lookup_system_key", 1 }, + { "bpf_key_put", 3 }, + }, + .result = REJECT, +}, +{ + "reference tracking: release with NULL key pointer", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "arg#0 pointer type STRUCT bpf_key must point to scalar, or struct with scalar", + .fixup_kfunc_btf_id = { + { "bpf_key_put", 1 }, + }, + .result = REJECT, +}, +{ + "reference tracking: leak potential reference to user key", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, -3), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "Unreleased reference", + .fixup_kfunc_btf_id = { + { "bpf_lookup_user_key", 2 }, + }, + .result = REJECT, +}, +{ + "reference tracking: leak potential reference to system key", + .insns = { + BPF_MOV64_IMM(BPF_REG_1, 1), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_KFUNC_CALL, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "bpf", + .expected_attach_type = BPF_LSM_MAC, + .flags = BPF_F_SLEEPABLE, + .errstr = "Unreleased reference", + .fixup_kfunc_btf_id = { + { "bpf_lookup_system_key", 1 }, + }, + .result = REJECT, +}, { "reference tracking: release reference without check", .insns = { From patchwork Fri Aug 12 10:19:01 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942130 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 970A0C32763 for ; Fri, 12 Aug 2022 10:21:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238490AbiHLKVc (ORCPT ); Fri, 12 Aug 2022 06:21:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238830AbiHLKVW (ORCPT ); Fri, 12 Aug 2022 06:21:22 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C944575FF7; Fri, 12 Aug 2022 03:21:20 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.206]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M402d1114z67XhD; Fri, 12 Aug 2022 18:16:41 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:21:17 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v11 8/9] selftests/bpf: Add additional tests for bpf_lookup_*_key() Date: Fri, 12 Aug 2022 12:19:01 +0200 Message-ID: <20220812101902.2846182-9-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Add a test to ensure that bpf_lookup_user_key() creates a referenced special keyring when the KEY_LOOKUP_CREATE flag is passed to this function. Ensure that the kfunc rejects invalid flags. Ensure that a keyring can be obtained from bpf_lookup_system_key() when one of the pre-determined keyring IDs is provided. Signed-off-by: Roberto Sassu --- .../selftests/bpf/prog_tests/lookup_key.c | 112 ++++++++++++++++++ .../selftests/bpf/progs/test_lookup_key.c | 46 +++++++ 2 files changed, 158 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/lookup_key.c create mode 100644 tools/testing/selftests/bpf/progs/test_lookup_key.c diff --git a/tools/testing/selftests/bpf/prog_tests/lookup_key.c b/tools/testing/selftests/bpf/prog_tests/lookup_key.c new file mode 100644 index 000000000000..2e0cde729dc7 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/lookup_key.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu + */ + +#include +#include + +#include "test_lookup_key.skel.h" + +#define KEY_LOOKUP_CREATE 0x01 +#define KEY_LOOKUP_PARTIAL 0x02 + +static bool kfunc_not_supported; + +static int libbpf_print_cb(enum libbpf_print_level level, const char *fmt, + va_list args) +{ + char *func; + + if (strcmp(fmt, "libbpf: extern (func ksym) '%s': not found in kernel or module BTFs\n")) + return 0; + + func = va_arg(args, char *); + + if (strcmp(func, "bpf_lookup_user_key") && strcmp(func, "bpf_key_put") && + strcmp(func, "bpf_lookup_system_key")) + return 0; + + kfunc_not_supported = true; + return 0; +} + +void test_lookup_key(void) +{ + libbpf_print_fn_t old_print_cb; + struct test_lookup_key *skel; + u32 next_id; + int ret; + + skel = test_lookup_key__open(); + if (!ASSERT_OK_PTR(skel, "test_lookup_key__open")) + return; + + old_print_cb = libbpf_set_print(libbpf_print_cb); + ret = test_lookup_key__load(skel); + libbpf_set_print(old_print_cb); + + if (ret < 0 && kfunc_not_supported) { + printf("%s:SKIP:bpf_lookup_*_key(), bpf_key_put() kfuncs not supported\n", + __func__); + test__skip(); + goto close_prog; + } + + if (!ASSERT_OK(ret, "test_lookup_key__load")) + goto close_prog; + + ret = test_lookup_key__attach(skel); + if (!ASSERT_OK(ret, "test_lookup_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); + if (!ASSERT_LT(ret, 0, "bpf_prog_get_next_id")) + goto close_prog; + + skel->bss->key_serial = 0; + skel->bss->key_id = 1; + + ret = bpf_prog_get_next_id(0, &next_id); + if (!ASSERT_OK(ret, "bpf_prog_get_next_id")) + goto close_prog; + + skel->bss->key_id = UINT32_MAX; + + ret = bpf_prog_get_next_id(0, &next_id); + ASSERT_LT(ret, 0, "bpf_prog_get_next_id"); + +close_prog: + skel->bss->monitored_pid = 0; + test_lookup_key__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/test_lookup_key.c b/tools/testing/selftests/bpf/progs/test_lookup_key.c new file mode 100644 index 000000000000..c73776990ae3 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_lookup_key.c @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu + */ + +#include "vmlinux.h" +#include +#include +#include + +char _license[] SEC("license") = "GPL"; + +__u32 monitored_pid; +__u32 key_serial; +__u32 key_id; +__u64 flags; + +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; + +SEC("lsm.s/bpf") +int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size) +{ + struct bpf_key *bkey; + __u32 pid; + + pid = bpf_get_current_pid_tgid() >> 32; + if (pid != monitored_pid) + return 0; + + if (key_serial) + bkey = bpf_lookup_user_key(key_serial, flags); + else + bkey = bpf_lookup_system_key(key_id); + + if (!bkey) + return -ENOENT; + + bpf_key_put(bkey); + + return 0; +} From patchwork Fri Aug 12 10:19:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12942134 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 72C2CC2BB41 for ; Fri, 12 Aug 2022 10:21:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237530AbiHLKVf (ORCPT ); Fri, 12 Aug 2022 06:21:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238841AbiHLKVY (ORCPT ); Fri, 12 Aug 2022 06:21:24 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CEB8883EA; Fri, 12 Aug 2022 03:21:22 -0700 (PDT) Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4M407t1FKmz688p7; Fri, 12 Aug 2022 18:21:14 +0800 (CST) Received: from roberto-ThinkStation-P620.huawei.com (10.204.63.22) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Fri, 12 Aug 2022 12:21:19 +0200 From: Roberto Sassu To: , , , , , , , , , , , , , , , , , , , , CC: , , , , , , Roberto Sassu Subject: [PATCH v11 9/9] selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc Date: Fri, 12 Aug 2022 12:19:02 +0200 Message-ID: <20220812101902.2846182-10-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220812101902.2846182-1-roberto.sassu@huawei.com> References: <20220812101902.2846182-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.63.22] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: Perform several tests to ensure the correct implementation of the bpf_verify_pkcs7_signature() kfunc. Do the tests with data signed with a generated testing key (by using sign-file from scripts/) and with the tcp_bic.ko kernel module if it is found in the system. The test does not fail if tcp_bic.ko is not found. First, perform an unsuccessful signature verification without data. Second, perform a successful signature verification with the session keyring and a new one created for testing. Then, ensure that permission and validation checks are done properly on the keyring provided to bpf_verify_pkcs7_signature(), despite those checks were deferred at the time the keyring was retrieved with bpf_lookup_user_key(). The tests expect to encounter an error if the Search permission is removed from the keyring, or the keyring is expired. Finally, perform a successful and unsuccessful signature verification with the keyrings with pre-determined IDs (the last test fails because the key is not in the platform keyring). Signed-off-by: Roberto Sassu --- tools/testing/selftests/bpf/Makefile | 14 +- tools/testing/selftests/bpf/config | 5 + tools/testing/selftests/bpf/config.x86_64 | 5 - .../bpf/prog_tests/verify_pkcs7_sig.c | 399 ++++++++++++++++++ .../bpf/progs/test_verify_pkcs7_sig.c | 100 +++++ .../testing/selftests/bpf/verify_sig_setup.sh | 104 +++++ 6 files changed, 619 insertions(+), 8 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/verify_pkcs7_sig.c create mode 100644 tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c create mode 100755 tools/testing/selftests/bpf/verify_sig_setup.sh diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 8d59ec7f4c2d..5ae079e276b3 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -14,6 +14,7 @@ BPFTOOLDIR := $(TOOLSDIR)/bpf/bpftool APIDIR := $(TOOLSINCDIR)/uapi GENDIR := $(abspath ../../../../include/generated) GENHDR := $(GENDIR)/autoconf.h +HOSTPKG_CONFIG := pkg-config ifneq ($(wildcard $(GENHDR)),) GENFLAGS := -DHAVE_GENHDR @@ -75,7 +76,7 @@ TEST_PROGS := test_kmod.sh \ test_xsk.sh TEST_PROGS_EXTENDED := with_addr.sh \ - with_tunnels.sh ima_setup.sh \ + with_tunnels.sh ima_setup.sh verify_sig_setup.sh \ test_xdp_vlan.sh test_bpftool.py # Compile but not part of 'make run_tests' @@ -84,7 +85,7 @@ TEST_GEN_PROGS_EXTENDED = test_sock_addr test_skb_cgroup_id_user \ test_lirc_mode2_user xdping test_cpp runqslower bench bpf_testmod.ko \ xskxceiver xdp_redirect_multi xdp_synproxy -TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read +TEST_CUSTOM_PROGS = $(OUTPUT)/urandom_read $(OUTPUT)/sign-file # Emit succinct information message describing current building step # $1 - generic step name (e.g., CC, LINK, etc); @@ -189,6 +190,12 @@ $(OUTPUT)/urandom_read: urandom_read.c urandom_read_aux.c $(OUTPUT)/liburandom_r -fuse-ld=$(LLD) -Wl,-znoseparate-code \ -Wl,-rpath=. -Wl,--build-id=sha1 -o $@ +$(OUTPUT)/sign-file: ../../../../scripts/sign-file.c + $(call msg,SIGN-FILE,,$@) + $(Q)$(CC) $(shell $(HOSTPKG_CONFIG)--cflags libcrypto 2> /dev/null) \ + $< -o $@ \ + $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto) + $(OUTPUT)/bpf_testmod.ko: $(VMLINUX_BTF) $(wildcard bpf_testmod/Makefile bpf_testmod/*.[ch]) $(call msg,MOD,,$@) $(Q)$(RM) bpf_testmod/bpf_testmod.ko # force re-compilation @@ -514,7 +521,8 @@ TRUNNER_EXTRA_SOURCES := test_progs.c cgroup_helpers.c trace_helpers.c \ TRUNNER_EXTRA_FILES := $(OUTPUT)/urandom_read $(OUTPUT)/bpf_testmod.ko \ $(OUTPUT)/liburandom_read.so \ $(OUTPUT)/xdp_synproxy \ - ima_setup.sh \ + $(OUTPUT)/sign-file \ + ima_setup.sh verify_sig_setup.sh \ $(wildcard progs/btf_dump_test_case_*.c) TRUNNER_BPF_BUILD_RULE := CLANG_BPF_BUILD_RULE TRUNNER_BPF_CFLAGS := $(BPF_CFLAGS) $(CLANG_CFLAGS) -DENABLE_ATOMICS_TESTS diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config index c99b196aa840..e95b557a5c93 100644 --- a/tools/testing/selftests/bpf/config +++ b/tools/testing/selftests/bpf/config @@ -33,6 +33,11 @@ CONFIG_IPV6_TUNNEL=y CONFIG_KEYS=y CONFIG_LIRC=y CONFIG_LWTUNNEL=y +CONFIG_MODULE_SIG=y +CONFIG_MODULE_SRCVERSION_ALL=y +CONFIG_MODULE_UNLOAD=y +CONFIG_MODULES=y +CONFIG_MODVERSIONS=y CONFIG_MPLS=y CONFIG_MPLS_IPTUNNEL=m CONFIG_MPLS_ROUTING=m diff --git a/tools/testing/selftests/bpf/config.x86_64 b/tools/testing/selftests/bpf/config.x86_64 index f0859a1d37ab..9d5709e0c5b1 100644 --- a/tools/testing/selftests/bpf/config.x86_64 +++ b/tools/testing/selftests/bpf/config.x86_64 @@ -145,11 +145,6 @@ CONFIG_MCORE2=y CONFIG_MEMCG=y CONFIG_MEMORY_FAILURE=y CONFIG_MINIX_SUBPARTITION=y -CONFIG_MODULE_SIG=y -CONFIG_MODULE_SRCVERSION_ALL=y -CONFIG_MODULE_UNLOAD=y -CONFIG_MODULES=y -CONFIG_MODVERSIONS=y CONFIG_NAMESPACES=y CONFIG_NET=y CONFIG_NET_9P=y diff --git a/tools/testing/selftests/bpf/prog_tests/verify_pkcs7_sig.c b/tools/testing/selftests/bpf/prog_tests/verify_pkcs7_sig.c new file mode 100644 index 000000000000..20be68d4cce4 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/verify_pkcs7_sig.c @@ -0,0 +1,399 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH + * + * Author: Roberto Sassu + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "test_verify_pkcs7_sig.skel.h" + +#define MAX_DATA_SIZE (1024 * 1024) +#define MAX_SIG_SIZE 1024 + +#define VERIFY_USE_SECONDARY_KEYRING (1UL) +#define VERIFY_USE_PLATFORM_KEYRING (2UL) + +/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */ +#define MODULE_SIG_STRING "~Module signature appended~\n" + +/* + * Module signature information block. + * + * The constituents of the signature section are, in order: + * + * - Signer's name + * - Key identifier + * - Signature data + * - Information block + */ +struct module_signature { + u8 algo; /* Public-key crypto algorithm [0] */ + u8 hash; /* Digest algorithm [0] */ + u8 id_type; /* Key identifier type [PKEY_ID_PKCS7] */ + u8 signer_len; /* Length of signer's name [0] */ + u8 key_id_len; /* Length of key identifier [0] */ + u8 __pad[3]; + __be32 sig_len; /* Length of signature data */ +}; + +struct data { + u8 data[MAX_DATA_SIZE]; + u32 data_len; + u8 sig[MAX_SIG_SIZE]; + u32 sig_len; +}; + +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 int _run_setup_process(const char *setup_dir, const char *cmd) +{ + int child_pid, child_status; + + child_pid = fork(); + if (child_pid == 0) { + execlp("./verify_sig_setup.sh", "./verify_sig_setup.sh", cmd, + setup_dir, NULL); + exit(errno); + + } else if (child_pid > 0) { + waitpid(child_pid, &child_status, 0); + return WEXITSTATUS(child_status); + } + + return -EINVAL; +} + +static int populate_data_item_str(const char *tmp_dir, struct data *data_item) +{ + struct stat st; + char data_template[] = "/tmp/dataXXXXXX"; + char path[PATH_MAX]; + int ret, fd, child_status, child_pid; + + data_item->data_len = 4; + memcpy(data_item->data, "test", data_item->data_len); + + fd = mkstemp(data_template); + if (fd == -1) + return -errno; + + ret = write(fd, data_item->data, data_item->data_len); + + close(fd); + + if (ret != data_item->data_len) { + ret = -EIO; + goto out; + } + + child_pid = fork(); + + if (child_pid == -1) { + ret = -errno; + goto out; + } + + if (child_pid == 0) { + snprintf(path, sizeof(path), "%s/signing_key.pem", tmp_dir); + + return execlp("./sign-file", "./sign-file", "-d", "sha256", + path, path, data_template, NULL); + } + + waitpid(child_pid, &child_status, 0); + + ret = WEXITSTATUS(child_status); + if (ret) + goto out; + + snprintf(path, sizeof(path), "%s.p7s", data_template); + + ret = stat(path, &st); + if (ret == -1) { + ret = -errno; + goto out; + } + + if (st.st_size > sizeof(data_item->sig)) { + ret = -EINVAL; + goto out_sig; + } + + data_item->sig_len = st.st_size; + + fd = open(path, O_RDONLY); + if (fd == -1) { + ret = -errno; + goto out_sig; + } + + ret = read(fd, data_item->sig, data_item->sig_len); + + close(fd); + + if (ret != data_item->sig_len) { + ret = -EIO; + goto out_sig; + } + + ret = 0; +out_sig: + unlink(path); +out: + unlink(data_template); + return ret; +} + +static int populate_data_item_mod(struct data *data_item) +{ + char mod_path[PATH_MAX], *mod_path_ptr; + struct stat st; + void *mod; + FILE *fp; + struct module_signature ms; + int ret, fd, modlen, marker_len, sig_len; + + data_item->data_len = 0; + + if (stat("/lib/modules", &st) == -1) + return 0; + + /* Requires CONFIG_TCP_CONG_BIC=m. */ + fp = popen("find /lib/modules/$(uname -r) -name tcp_bic.ko", "r"); + if (!fp) + return 0; + + mod_path_ptr = fgets(mod_path, sizeof(mod_path), fp); + pclose(fp); + + if (!mod_path_ptr) + return 0; + + mod_path_ptr = strchr(mod_path, '\n'); + if (!mod_path_ptr) + return 0; + + *mod_path_ptr = '\0'; + + if (stat(mod_path, &st) == -1) + return 0; + + modlen = st.st_size; + marker_len = sizeof(MODULE_SIG_STRING) - 1; + + fd = open(mod_path, O_RDONLY); + if (fd == -1) + return -errno; + + mod = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); + + close(fd); + + if (mod == MAP_FAILED) + return -errno; + + if (strncmp(mod + modlen - marker_len, MODULE_SIG_STRING, marker_len)) { + ret = -EINVAL; + goto out; + } + + modlen -= marker_len; + + memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms)); + + sig_len = __be32_to_cpu(ms.sig_len); + modlen -= sig_len + sizeof(ms); + + if (modlen > sizeof(data_item->data)) { + ret = -E2BIG; + goto out; + } + + memcpy(data_item->data, mod, modlen); + data_item->data_len = modlen; + + if (sig_len > sizeof(data_item->sig)) { + ret = -E2BIG; + goto out; + } + + memcpy(data_item->sig, mod + modlen, sig_len); + data_item->sig_len = sig_len; + ret = 0; +out: + munmap(mod, st.st_size); + return ret; +} + +void test_verify_pkcs7_sig(void) +{ + libbpf_print_fn_t old_print_cb; + char tmp_dir_template[] = "/tmp/verify_sigXXXXXX"; + char *tmp_dir; + struct test_verify_pkcs7_sig *skel = NULL; + struct bpf_map *map; + struct data data; + int ret, zero = 0; + + /* Trigger creation of session keyring. */ + syscall(__NR_request_key, "keyring", "_uid.0", NULL, + KEY_SPEC_SESSION_KEYRING); + + tmp_dir = mkdtemp(tmp_dir_template); + if (!ASSERT_OK_PTR(tmp_dir, "mkdtemp")) + return; + + ret = _run_setup_process(tmp_dir, "setup"); + if (!ASSERT_OK(ret, "_run_setup_process")) + goto close_prog; + + skel = test_verify_pkcs7_sig__open(); + if (!ASSERT_OK_PTR(skel, "test_verify_pkcs7_sig__open")) + goto close_prog; + + old_print_cb = libbpf_set_print(libbpf_print_cb); + ret = test_verify_pkcs7_sig__load(skel); + libbpf_set_print(old_print_cb); + + if (ret < 0 && kfunc_not_supported) { + printf( + "%s:SKIP:bpf_verify_pkcs7_signature() kfunc not supported\n", + __func__); + test__skip(); + goto close_prog; + } + + if (!ASSERT_OK(ret, "test_verify_pkcs7_sig__load")) + goto close_prog; + + ret = test_verify_pkcs7_sig__attach(skel); + if (!ASSERT_OK(ret, "test_verify_pkcs7_sig__attach")) + goto close_prog; + + map = bpf_object__find_map_by_name(skel->obj, "data_input"); + if (!ASSERT_OK_PTR(map, "data_input not found")) + goto close_prog; + + skel->bss->monitored_pid = getpid(); + + /* Test without data and signature. */ + skel->bss->user_keyring_serial = KEY_SPEC_SESSION_KEYRING; + + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, BPF_ANY); + if (!ASSERT_LT(ret, 0, "bpf_map_update_elem data_input")) + goto close_prog; + + /* Test successful signature verification with session keyring. */ + ret = populate_data_item_str(tmp_dir, &data); + if (!ASSERT_OK(ret, "populate_data_item_str")) + goto close_prog; + + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, BPF_ANY); + if (!ASSERT_OK(ret, "bpf_map_update_elem data_input")) + goto close_prog; + + /* Test successful signature verification with testing keyring. */ + skel->bss->user_keyring_serial = syscall(__NR_request_key, "keyring", + "ebpf_testing_keyring", NULL, + KEY_SPEC_SESSION_KEYRING); + + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, BPF_ANY); + if (!ASSERT_OK(ret, "bpf_map_update_elem data_input")) + goto close_prog; + + /* + * Ensure key_task_permission() is called and rejects the keyring + * (no Search permission). + */ + syscall(__NR_keyctl, KEYCTL_SETPERM, skel->bss->user_keyring_serial, + 0x37373737); + + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, BPF_ANY); + if (!ASSERT_LT(ret, 0, "bpf_map_update_elem data_input")) + goto close_prog; + + syscall(__NR_keyctl, KEYCTL_SETPERM, skel->bss->user_keyring_serial, + 0x3f3f3f3f); + + /* + * Ensure key_validate() is called and rejects the keyring (key expired) + */ + syscall(__NR_keyctl, KEYCTL_SET_TIMEOUT, + skel->bss->user_keyring_serial, 1); + sleep(1); + + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, BPF_ANY); + if (!ASSERT_LT(ret, 0, "bpf_map_update_elem data_input")) + goto close_prog; + + skel->bss->user_keyring_serial = KEY_SPEC_SESSION_KEYRING; + + /* Test with corrupted data (signature verification should fail). */ + data.data[0] = 'a'; + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, BPF_ANY); + if (!ASSERT_LT(ret, 0, "bpf_map_update_elem data_input")) + goto close_prog; + + ret = populate_data_item_mod(&data); + if (!ASSERT_OK(ret, "populate_data_item_mod")) + goto close_prog; + + /* Test signature verification with system keyrings. */ + if (data.data_len) { + skel->bss->user_keyring_serial = 0; + skel->bss->system_keyring_id = 0; + + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, + BPF_ANY); + if (!ASSERT_OK(ret, "bpf_map_update_elem data_input")) + goto close_prog; + + skel->bss->system_keyring_id = VERIFY_USE_SECONDARY_KEYRING; + + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, + BPF_ANY); + if (!ASSERT_OK(ret, "bpf_map_update_elem data_input")) + goto close_prog; + + skel->bss->system_keyring_id = VERIFY_USE_PLATFORM_KEYRING; + + ret = bpf_map_update_elem(bpf_map__fd(map), &zero, &data, + BPF_ANY); + ASSERT_LT(ret, 0, "bpf_map_update_elem data_input"); + } + +close_prog: + _run_setup_process(tmp_dir, "cleanup"); + + if (!skel) + return; + + skel->bss->monitored_pid = 0; + test_verify_pkcs7_sig__destroy(skel); +} 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 + */ + +#include "vmlinux.h" +#include +#include +#include + +#define MAX_DATA_SIZE (1024 * 1024) +#define MAX_SIG_SIZE 1024 + +typedef __u8 u8; +typedef __u16 u16; +typedef __u32 u32; +typedef __u64 u64; + +struct bpf_dynptr { + __u64 :64; + __u64 :64; +} __attribute__((aligned(8))); + +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), + (void *)(unsigned long)value); + + if (data_val->data_len > sizeof(data_val->data)) + return -EINVAL; + + bpf_dynptr_from_mem(data_val->data, data_val->data_len, 0, &data_ptr); + + if (data_val->sig_len > sizeof(data_val->sig)) + return -EINVAL; + + bpf_dynptr_from_mem(data_val->sig, data_val->sig_len, 0, &sig_ptr); + + if (user_keyring_serial) + trusted_keyring = bpf_lookup_user_key(user_keyring_serial, 0); + else + trusted_keyring = bpf_lookup_system_key(system_keyring_id); + + if (!trusted_keyring) + return -ENOENT; + + ret = bpf_verify_pkcs7_signature(&data_ptr, &sig_ptr, trusted_keyring); + + bpf_key_put(trusted_keyring); + + return ret; +} diff --git a/tools/testing/selftests/bpf/verify_sig_setup.sh b/tools/testing/selftests/bpf/verify_sig_setup.sh new file mode 100755 index 000000000000..ba08922b4a27 --- /dev/null +++ b/tools/testing/selftests/bpf/verify_sig_setup.sh @@ -0,0 +1,104 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +set -e +set -u +set -o pipefail + +VERBOSE="${SELFTESTS_VERBOSE:=0}" +LOG_FILE="$(mktemp /tmp/verify_sig_setup.log.XXXXXX)" + +x509_genkey_content="\ +[ req ] +default_bits = 2048 +distinguished_name = req_distinguished_name +prompt = no +string_mask = utf8only +x509_extensions = myexts + +[ req_distinguished_name ] +CN = eBPF Signature Verification Testing Key + +[ myexts ] +basicConstraints=critical,CA:FALSE +keyUsage=digitalSignature +subjectKeyIdentifier=hash +authorityKeyIdentifier=keyid +" + +usage() +{ + echo "Usage: $0 " + exit 1 +} + +setup() +{ + local tmp_dir="$1" + + echo "${x509_genkey_content}" > ${tmp_dir}/x509.genkey + + openssl req -new -nodes -utf8 -sha256 -days 36500 \ + -batch -x509 -config ${tmp_dir}/x509.genkey \ + -outform PEM -out ${tmp_dir}/signing_key.pem \ + -keyout ${tmp_dir}/signing_key.pem 2>&1 + + openssl x509 -in ${tmp_dir}/signing_key.pem -out \ + ${tmp_dir}/signing_key.der -outform der + + key_id=$(cat ${tmp_dir}/signing_key.der | keyctl padd asymmetric ebpf_testing_key @s) + + keyring_id=$(keyctl newring ebpf_testing_keyring @s) + keyctl link $key_id $keyring_id +} + +cleanup() { + local tmp_dir="$1" + + keyctl unlink $(keyctl search @s asymmetric ebpf_testing_key) @s + keyctl unlink $(keyctl search @s keyring ebpf_testing_keyring) @s + rm -rf ${tmp_dir} +} + +catch() +{ + local exit_code="$1" + local log_file="$2" + + if [[ "${exit_code}" -ne 0 ]]; then + cat "${log_file}" >&3 + fi + + rm -f "${log_file}" + exit ${exit_code} +} + +main() +{ + [[ $# -ne 2 ]] && usage + + local action="$1" + local tmp_dir="$2" + + [[ ! -d "${tmp_dir}" ]] && echo "Directory ${tmp_dir} doesn't exist" && exit 1 + + if [[ "${action}" == "setup" ]]; then + setup "${tmp_dir}" + elif [[ "${action}" == "cleanup" ]]; then + cleanup "${tmp_dir}" + else + echo "Unknown action: ${action}" + exit 1 + fi +} + +trap 'catch "$?" "${LOG_FILE}"' EXIT + +if [[ "${VERBOSE}" -eq 0 ]]; then + # Save the stderr to 3 so that we can output back to + # it incase of an error. + exec 3>&2 1>"${LOG_FILE}" 2>&1 +fi + +main "$@" +rm -f "${LOG_FILE}"