From patchwork Tue Apr 25 17:35:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 677045 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 9A4E6C77B61 for ; Tue, 25 Apr 2023 17:39:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234803AbjDYRjJ (ORCPT ); Tue, 25 Apr 2023 13:39:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234762AbjDYRjH (ORCPT ); Tue, 25 Apr 2023 13:39:07 -0400 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2B9B114F5F; Tue, 25 Apr 2023 10:38:41 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.227]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4Q5TWG6w3Cz9xFQD; Wed, 26 Apr 2023 01:28:58 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwD3dADLD0hkGxlWAg--.5466S6; Tue, 25 Apr 2023 18:38:16 +0100 (CET) From: Roberto Sassu To: dhowells@redhat.com, dwmw2@infradead.org, herbert@gondor.apana.org.au, davem@davemloft.net, jarkko@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, rostedt@goodmis.org, mhiramat@kernel.org, mykolal@fb.com, shuah@kernel.org Cc: linux-kernel@vger.kernel.org, keyrings@vger.kernel.org, linux-crypto@vger.kernel.org, bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Roberto Sassu Subject: [RFC][PATCH 4/6] bpf: Introduce bpf_verify_umd_signature() kfunc Date: Tue, 25 Apr 2023 19:35:55 +0200 Message-Id: <20230425173557.724688-5-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230425173557.724688-1-roberto.sassu@huaweicloud.com> References: <20230425173557.724688-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: LxC2BwD3dADLD0hkGxlWAg--.5466S6 X-Coremail-Antispam: 1UD129KBjvJXoWxCr4UJFWkuFW5uryUWryfZwb_yoWrWr1rpF W8Krsavry8Jrs7Ja4rJa1fZF4FkF4vqw17G3sFk3s7uFn5Xr13Z348KF4UG3s0k348trWD ZrWIqw45u3W7GaUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPlb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW8JVW5JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_Gr0_Cr1l84ACjcxK6I8E87Iv6xkF7I0E 14v26r4UJVWxJr1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrV C2j2WlYx0E2Ix0cI8IcVAFwI0_Jrv_JF1lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE 7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCY1x0262 kKe7AKxVW8ZVWrXwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s02 6c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_GF v_WrylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVW8JVW5JwCI42IY6xIIjxv20xvE c7CjxVAFwI0_Gr1j6F4UJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aV AFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW8Jr0_Cr1UYxBIdaVFxhVjvjDU0xZF pf9x07jxwIDUUUUU= X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQASBF1jj4x8NAAAsi X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Roberto Sassu Introduce the bpf_verify_umd_signature() kfunc, to verify UMD-parsed signatures. The parameters and usage are the same as for bpf_verify_pkcs7_signature(). Signed-off-by: Roberto Sassu --- kernel/trace/bpf_trace.c | 69 ++++++++++++++++++++++++++++++++-------- 1 file changed, 55 insertions(+), 14 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index e8da032bb6f..c9cae337596 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1271,7 +1271,7 @@ __bpf_kfunc struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags) * 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(). + * verify_pkcs7_signature() and verify_umd_signature(). * * Set *id* to one of the values defined in include/linux/verification.h: * 0 for the primary keyring (immutable keyring of system keys); @@ -1317,6 +1317,27 @@ __bpf_kfunc void bpf_key_put(struct bpf_key *bkey) } #ifdef CONFIG_SYSTEM_DATA_VERIFICATION +static int validate_key(struct bpf_key *trusted_keyring) +{ + int ret = 0; + + 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 ret; +} + /** * bpf_verify_pkcs7_signature - verify a PKCS#7 signature * @data_ptr: data to verify @@ -1334,19 +1355,9 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, { 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; - } + ret = validate_key(trusted_keyring); + if (ret < 0) + return ret; return verify_pkcs7_signature(data_ptr->data, bpf_dynptr_get_size(data_ptr), @@ -1356,6 +1367,35 @@ __bpf_kfunc int bpf_verify_pkcs7_signature(struct bpf_dynptr_kern *data_ptr, VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL); } + +/** + * bpf_verify_umd_signature - Verify a UMD-parsed signature + * @data_ptr: Data to verify + * @sig_ptr: Signature of the data + * @trusted_keyring: Keyring with keys trusted for signature verification + * + * Verify the UMD-parsed 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. + */ +__bpf_kfunc int bpf_verify_umd_signature(struct bpf_dynptr_kern *data_ptr, + struct bpf_dynptr_kern *sig_ptr, + struct bpf_key *trusted_keyring) +{ + int ret; + + ret = validate_key(trusted_keyring); + if (ret < 0) + return ret; + + return verify_umd_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(); @@ -1366,6 +1406,7 @@ 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) +BTF_ID_FLAGS(func, bpf_verify_umd_signature, KF_SLEEPABLE) #endif BTF_SET8_END(key_sig_kfunc_set)