From patchwork Fri Oct 28 16:49:48 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13024049 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 3C32DFA3743 for ; Fri, 28 Oct 2022 16:51:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230018AbiJ1QvG (ORCPT ); Fri, 28 Oct 2022 12:51:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48994 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230077AbiJ1QvB (ORCPT ); Fri, 28 Oct 2022 12:51:01 -0400 Received: from frasgout11.his.huawei.com (frasgout11.his.huawei.com [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C82EC82619; Fri, 28 Oct 2022 09:50:49 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4MzT0N1hMDz9xqxV; Sat, 29 Oct 2022 00:44:20 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwD3LPk3CFxjeW4cAA--.34547S4; Fri, 28 Oct 2022 17:50:30 +0100 (CET) From: Roberto Sassu To: 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, mykolal@fb.com, revest@chromium.org, jackmanb@chromium.org, shuah@kernel.org, paul@paul-moore.com, casey@schaufler-ca.com Cc: bpf@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC][PATCH 3/3] selftests/bpf: Check if return values of LSM programs are allowed Date: Fri, 28 Oct 2022 18:49:48 +0200 Message-Id: <20221028164948.385783-3-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221028164948.385783-1-roberto.sassu@huaweicloud.com> References: <20221028164948.385783-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: GxC2BwD3LPk3CFxjeW4cAA--.34547S4 X-Coremail-Antispam: 1UD129KBjvJXoWxJF1kAr4UAFyxAr48Cr17ZFb_yoWrZw1Dp3 WrZw1jkF40vF4avFWrK397uayS9FW7CrW5KwnxZwnrZa97JF4xW3W5tFy5Zr13Gr15Gr9Y qr17Can5u3WUZa7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPab4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVWUJVWUCwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ Gr1j6F4UJwAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG6I80ew Av7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY 6r1j6r4UM4x0Y48IcxkI7VAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS14 v26r4a6rW5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I8C rVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWrXw CIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x02 67AKxVWxJVW8Jr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r 1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyTuYvjxU IID7DUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgATBF1jj4DNhQAAss X-CFilter-Loop: Reflected Precedence: bulk List-ID: From: Roberto Sassu Ensure that the eBPF verifier allows to load only LSM programs that return an allowed value depending on the LSM hook they attach to. Signed-off-by: Roberto Sassu --- .../testing/selftests/bpf/verifier/lsm_ret.c | 148 ++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 tools/testing/selftests/bpf/verifier/lsm_ret.c diff --git a/tools/testing/selftests/bpf/verifier/lsm_ret.c b/tools/testing/selftests/bpf/verifier/lsm_ret.c new file mode 100644 index 000000000000..1a11f47fb24a --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/lsm_ret.c @@ -0,0 +1,148 @@ +{ + "lsm return value: positive not allowed, return -EPERM", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, -EPERM), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "inode_permission", + .expected_attach_type = BPF_LSM_MAC, + .result = ACCEPT, +}, +{ + "lsm return value: positive not allowed, return zero", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "inode_permission", + .expected_attach_type = BPF_LSM_MAC, + .result = ACCEPT, +}, +{ + "lsm return value: positive not allowed, return one", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "inode_permission", + .expected_attach_type = BPF_LSM_MAC, + .errstr = "Invalid R0, cannot return positive value", + .result = REJECT, +}, +{ + "lsm return value: zero/positive not allowed, return -EPERM", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, -EPERM), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "inode_init_security", + .expected_attach_type = BPF_LSM_MAC, + .result = ACCEPT, +}, +{ + "lsm return value: zero/positive not allowed, return zero", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "inode_init_security", + .expected_attach_type = BPF_LSM_MAC, + .errstr = "Invalid R0, cannot return zero value", + .result = REJECT, +}, +{ + "lsm return value: zero/positive not allowed, return one", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "inode_init_security", + .expected_attach_type = BPF_LSM_MAC, + .errstr = "Invalid R0, cannot return positive value", + .result = REJECT, +}, +{ + "lsm return value: positive allowed, return one", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "getprocattr", + .expected_attach_type = BPF_LSM_MAC, + .result = ACCEPT, +}, +{ + "lsm return value: positive allowed, return two", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "getprocattr", + .expected_attach_type = BPF_LSM_MAC, + .result = ACCEPT, +}, +{ + "lsm return value: only one allowed, return one", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "audit_rule_match", + .expected_attach_type = BPF_LSM_MAC, + .result = ACCEPT, +}, +{ + "lsm return value: only one allowed, return two", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 2), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "audit_rule_match", + .expected_attach_type = BPF_LSM_MAC, + .errstr = "Invalid R0, can return only one as positive value", + .result = REJECT, +}, +{ + "lsm return value: negative not allowed, return -EPERM", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, -EPERM), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "vm_enough_memory", + .expected_attach_type = BPF_LSM_MAC, + .errstr = "Invalid R0, cannot return negative value", + .result = REJECT, +}, +{ + "lsm return value: negative not allowed, return zero", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "vm_enough_memory", + .expected_attach_type = BPF_LSM_MAC, + .result = ACCEPT, +}, +{ + "lsm return value: negative not allowed, return one", + .insns = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_LSM, + .kfunc = "vm_enough_memory", + .expected_attach_type = BPF_LSM_MAC, + .result = ACCEPT, +},