From patchwork Mon Oct 19 19:42:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 11845043 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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9AF7C433E7 for ; Mon, 19 Oct 2020 19:42:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 710B122365 for ; Mon, 19 Oct 2020 19:42:25 +0000 (UTC) Authentication-Results: mail.kernel.org; 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Mon, 19 Oct 2020 12:42:24 -0700 Received: from intmgw002.03.ash8.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 19 Oct 2020 12:42:22 -0700 Received: by devbig005.ftw2.facebook.com (Postfix, from userid 6611) id 3081C2946269; Mon, 19 Oct 2020 12:42:19 -0700 (PDT) From: Martin KaFai Lau To: CC: Alexei Starovoitov , Daniel Borkmann , Hao Luo , , , Yonghong Song Subject: [PATCH bpf 2/3] bpf: selftest: Ensure the return value of bpf_skc_to helpers must be checked Date: Mon, 19 Oct 2020 12:42:19 -0700 Message-ID: <20201019194219.1051314-1-kafai@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20201019194206.1050591-1-kafai@fb.com> References: <20201019194206.1050591-1-kafai@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-10-19_10:2020-10-16,2020-10-19 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 mlxscore=0 clxscore=1015 suspectscore=13 adultscore=0 priorityscore=1501 bulkscore=0 impostorscore=0 malwarescore=0 spamscore=0 lowpriorityscore=0 phishscore=0 mlxlogscore=790 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2010190132 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This patch tests: int bpf_cls(struct __sk_buff *skb) { /* REG_6: sk * REG_7: tp * REG_8: req_sk */ sk = skb->sk; if (!sk) return 0; tp = bpf_skc_to_tcp_sock(sk); req_sk = bpf_skc_to_tcp_request_sock(sk); if (!req_sk) return 0; /* !tp has not been tested, so verifier should reject. */ return *(__u8 *)tp; } Signed-off-by: Martin KaFai Lau --- tools/testing/selftests/bpf/verifier/sock.c | 25 +++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/tools/testing/selftests/bpf/verifier/sock.c b/tools/testing/selftests/bpf/verifier/sock.c index b1aac2641498..ce13ece08d51 100644 --- a/tools/testing/selftests/bpf/verifier/sock.c +++ b/tools/testing/selftests/bpf/verifier/sock.c @@ -631,3 +631,28 @@ .prog_type = BPF_PROG_TYPE_SK_REUSEPORT, .result = ACCEPT, }, +{ + "mark null check on return value of bpf_skc_to helpers", + .insns = { + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_1, offsetof(struct __sk_buff, sk)), + BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_EMIT_CALL(BPF_FUNC_skc_to_tcp_sock), + BPF_MOV64_REG(BPF_REG_7, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_skc_to_tcp_request_sock), + BPF_MOV64_REG(BPF_REG_8, BPF_REG_0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_8, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_7, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = REJECT, + .errstr = "invalid mem access", + .result_unpriv = REJECT, + .errstr_unpriv = "unknown func", +},