From patchwork Sun Jan 30 11:55:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Sitnicki X-Patchwork-Id: 12729805 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 166DDC433FE for ; Sun, 30 Jan 2022 11:55:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354722AbiA3LzZ (ORCPT ); Sun, 30 Jan 2022 06:55:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236399AbiA3LzX (ORCPT ); Sun, 30 Jan 2022 06:55:23 -0500 Received: from mail-lj1-x22d.google.com (mail-lj1-x22d.google.com [IPv6:2a00:1450:4864:20::22d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD1ABC061714 for ; Sun, 30 Jan 2022 03:55:22 -0800 (PST) Received: by mail-lj1-x22d.google.com with SMTP id z20so15573978ljo.6 for ; Sun, 30 Jan 2022 03:55:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=pW0HJO+D1Fw6jhblBLImzq7tz0T2dvMaNsNBAeCsUSA=; b=LnsiT5QTgsVFMwEGS4dq1HVWNktIzrht5NOm+55QgGyTyVbUog0IIRiP7HB0VEcW0H MrHIy3pjpzDC3vslRL4YRsw2oDSa/GbtWBTO1xY45LfZovc1hhkslJJtE66Zhhq4kqQ5 +c8CBK8e3ELxWI7Ssp88Bk63ckpfKuOD1GgPM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=pW0HJO+D1Fw6jhblBLImzq7tz0T2dvMaNsNBAeCsUSA=; b=5Sf+rCF6mLZHYmC2u1smXBCVX0Z6sg4JYM1wWj0Unc54bc9cxtOPtr1glxnWNeGxx8 JhsRlXctkOWyE+7i088/7emYRfI8MkE5Ay9Gwkq1SU3+U0biQlFIwdTcagUGurTksHMC CRciADvu4jWaVjDz4Q0sviIb/phi7OKUjjqCk1jkMj/FaNy17dETbT7bBK1YigK+gH7w SAOlJFVoi4jmF591zpcZQ9Bvw+12IMqcgTRakmEhQWHeL+HLRDtLaNPm0kRWC9FTUwQq 7Gx3No3pLiSRn4pCaXVubtvyXvph0tLedcC/c9NNZJ2Hj6cFzTcyuOt2BTdPR/zyWPsL mmxg== X-Gm-Message-State: AOAM530ottZWO5W+XHe/LRseYdF23IpQJVi4wqb8/eljeePyTgE4Bvuy swBStCA8RVEmTarmyNJg0y3u5hLOGMcMbg== X-Google-Smtp-Source: ABdhPJxLxdjVQTnA+gLsUhDPnrXA0zNWFdlIN26U0EKO0e/hIiBDSsBaEsChwvgVfKc4QgAT6VS+ug== X-Received: by 2002:a2e:a786:: with SMTP id c6mr10333403ljf.385.1643543721036; Sun, 30 Jan 2022 03:55:21 -0800 (PST) Received: from cloudflare.com (2a01-110f-4809-d800-0000-0000-0000-0e00.aa.ipv6.supernova.orange.pl. [2a01:110f:4809:d800::e00]) by smtp.gmail.com with ESMTPSA id f11sm2339618lfg.132.2022.01.30.03.55.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 30 Jan 2022 03:55:20 -0800 (PST) From: Jakub Sitnicki To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Menglong Dong , Martin KaFai Lau Subject: [PATCH bpf-next v2 1/2] bpf: Make dst_port field in struct bpf_sock 16-bit wide Date: Sun, 30 Jan 2022 12:55:17 +0100 Message-Id: <20220130115518.213259-2-jakub@cloudflare.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220130115518.213259-1-jakub@cloudflare.com> References: <20220130115518.213259-1-jakub@cloudflare.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Menglong Dong reports that the documentation for the dst_port field in struct bpf_sock is inaccurate and confusing. From the BPF program PoV, the field is a zero-padded 16-bit integer in network byte order. The value appears to the BPF user as if laid out in memory as so: offsetof(struct bpf_sock, dst_port) + 0 + 8 +16 0x00 +24 0x00 32-, 16-, and 8-bit wide loads from the field are all allowed, but only if the offset into the field is 0. 32-bit wide loads from dst_port are especially confusing. The loaded value, after converting to host byte order with bpf_ntohl(dst_port), contains the port number in the upper 16-bits. Remove the confusion by splitting the field into two 16-bit fields. For backward compatibility, allow 32-bit wide loads from offsetof(struct bpf_sock, dst_port). While at it, allow loads 8-bit loads at offset [0] and [1] from dst_port. Reported-by: Menglong Dong Signed-off-by: Jakub Sitnicki --- include/uapi/linux/bpf.h | 3 ++- net/core/filter.c | 10 +++++++++- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 4a2f7041ebae..a7f0ddedac1f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -5574,7 +5574,8 @@ struct bpf_sock { __u32 src_ip4; __u32 src_ip6[4]; __u32 src_port; /* host byte order */ - __u32 dst_port; /* network byte order */ + __be16 dst_port; /* network byte order */ + __u16 :16; /* zero padding */ __u32 dst_ip4; __u32 dst_ip6[4]; __u32 state; diff --git a/net/core/filter.c b/net/core/filter.c index a06931c27eeb..99a05199a806 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -8265,6 +8265,7 @@ bool bpf_sock_is_valid_access(int off, int size, enum bpf_access_type type, struct bpf_insn_access_aux *info) { const int size_default = sizeof(__u32); + int field_size; if (off < 0 || off >= sizeof(struct bpf_sock)) return false; @@ -8276,7 +8277,6 @@ bool bpf_sock_is_valid_access(int off, int size, enum bpf_access_type type, case offsetof(struct bpf_sock, family): case offsetof(struct bpf_sock, type): case offsetof(struct bpf_sock, protocol): - case offsetof(struct bpf_sock, dst_port): case offsetof(struct bpf_sock, src_port): case offsetof(struct bpf_sock, rx_queue_mapping): case bpf_ctx_range(struct bpf_sock, src_ip4): @@ -8285,6 +8285,14 @@ bool bpf_sock_is_valid_access(int off, int size, enum bpf_access_type type, case bpf_ctx_range_till(struct bpf_sock, dst_ip6[0], dst_ip6[3]): bpf_ctx_record_field_size(info, size_default); return bpf_ctx_narrow_access_ok(off, size, size_default); + case bpf_ctx_range(struct bpf_sock, dst_port): + field_size = size == size_default ? + size_default : sizeof_field(struct bpf_sock, dst_port); + bpf_ctx_record_field_size(info, field_size); + return bpf_ctx_narrow_access_ok(off, size, field_size); + case offsetofend(struct bpf_sock, dst_port) ... + offsetof(struct bpf_sock, dst_ip4) - 1: + return false; } return size == size_default; From patchwork Sun Jan 30 11:55:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Sitnicki X-Patchwork-Id: 12729806 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 E54E8C4332F for ; Sun, 30 Jan 2022 11:55:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354714AbiA3Lz3 (ORCPT ); Sun, 30 Jan 2022 06:55:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1354719AbiA3LzY (ORCPT ); Sun, 30 Jan 2022 06:55:24 -0500 Received: from mail-lj1-x236.google.com (mail-lj1-x236.google.com [IPv6:2a00:1450:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFCD0C061741 for ; Sun, 30 Jan 2022 03:55:23 -0800 (PST) Received: by mail-lj1-x236.google.com with SMTP id t14so15555801ljh.8 for ; Sun, 30 Jan 2022 03:55:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=+OGuBVpqNFoYG8JaqojzZFjInF6N6dne6kUNztCH0Hk=; b=GgYxwBxBFNUvM69PA4aVJgdAwsPNg3AMKxZsYKFrFMuQap7+6DLM9+GouRro/PmbqM 6I6bY9waOh3DhD2LxX6XZeI8FR8nTqNQgJaQNbWzDVIXUbZ+81wKH+Ah06+YPkU04c1j fVwwPz2nq01FvCmJm07Tv3jrzTKTyGyK0RgKQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+OGuBVpqNFoYG8JaqojzZFjInF6N6dne6kUNztCH0Hk=; b=PVp5iQvKfpG5cXQAiqg60W2nbD3bFiiSVJFysgkoqmaYysxyrhQRz25H6lwlk3EqPf k79jqMn/haR8E1q3KTadMqrWXvvPPP7sGsqb2w6tuS7VQW2VZZgR+jMNBeAG8pptizDT Vl7WMjLg8oCYXM19ZelgqiF4b2TssFRxr91HAYGsV5MqjoaxpOt0uyvD0ioW2zzm6QgJ jk6y7KG3b200BpQ7EpedJABndQ1kBZOJoqMjkPCRHEpkRz2QV/AzsEMLeu0L4rGAzBvV hxUQagSQhWxb86O9o4bmni0dYSMwkQmc0udCCKekALvipX69eBYjey6xzVg9splMzPHS lDTw== X-Gm-Message-State: AOAM533sZfVvRdavqISuUonUI+2QQRHPbRD1PWtfl8scsuMwrWl3PWux x215VIAqRKtH4b+5OZr08MMH1Q== X-Google-Smtp-Source: ABdhPJwv1XUE+9Qj+xaGcUzHp7DH76pSasv49x8cSJv5vXTTWeZa5uB8CyZHxjyBUh48YCTplW9p5Q== X-Received: by 2002:a2e:a7ce:: with SMTP id x14mr10812274ljp.222.1643543721914; Sun, 30 Jan 2022 03:55:21 -0800 (PST) Received: from cloudflare.com (2a01-110f-4809-d800-0000-0000-0000-0e00.aa.ipv6.supernova.orange.pl. [2a01:110f:4809:d800::e00]) by smtp.gmail.com with ESMTPSA id q14sm1503194lfm.120.2022.01.30.03.55.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 30 Jan 2022 03:55:21 -0800 (PST) From: Jakub Sitnicki To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Menglong Dong , Martin KaFai Lau Subject: [PATCH bpf-next v2 2/2] selftests/bpf: Extend verifier and bpf_sock tests for dst_port loads Date: Sun, 30 Jan 2022 12:55:18 +0100 Message-Id: <20220130115518.213259-3-jakub@cloudflare.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220130115518.213259-1-jakub@cloudflare.com> References: <20220130115518.213259-1-jakub@cloudflare.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Add coverage to the verifier tests and tests for reading bpf_sock fields to ensure that 32-bit, 16-bit, and 8-bit loads from dst_port field are allowed only at intended offsets and produce expected values. While 16-bit and 8-bit access to dst_port field is straight-forward, 32-bit wide loads need be allowed and produce a zero-padded 16-bit value for backward compatibility. Signed-off-by: Jakub Sitnicki --- tools/include/uapi/linux/bpf.h | 3 +- .../selftests/bpf/prog_tests/sock_fields.c | 58 +++++++++---- .../selftests/bpf/progs/test_sock_fields.c | 41 ++++++++++ tools/testing/selftests/bpf/verifier/sock.c | 81 ++++++++++++++++++- 4 files changed, 162 insertions(+), 21 deletions(-) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 4a2f7041ebae..a7f0ddedac1f 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -5574,7 +5574,8 @@ struct bpf_sock { __u32 src_ip4; __u32 src_ip6[4]; __u32 src_port; /* host byte order */ - __u32 dst_port; /* network byte order */ + __be16 dst_port; /* network byte order */ + __u16 :16; /* zero padding */ __u32 dst_ip4; __u32 dst_ip6[4]; __u32 state; diff --git a/tools/testing/selftests/bpf/prog_tests/sock_fields.c b/tools/testing/selftests/bpf/prog_tests/sock_fields.c index 9fc040eaa482..9d211b5c22c4 100644 --- a/tools/testing/selftests/bpf/prog_tests/sock_fields.c +++ b/tools/testing/selftests/bpf/prog_tests/sock_fields.c @@ -1,9 +1,11 @@ // SPDX-License-Identifier: GPL-2.0 /* Copyright (c) 2019 Facebook */ +#define _GNU_SOURCE #include #include #include +#include #include #include #include @@ -20,6 +22,7 @@ enum bpf_linum_array_idx { EGRESS_LINUM_IDX, INGRESS_LINUM_IDX, + READ_SK_DST_PORT_LINUM_IDX, __NR_BPF_LINUM_ARRAY_IDX, }; @@ -42,8 +45,16 @@ static __u64 child_cg_id; static int linum_map_fd; static __u32 duration; -static __u32 egress_linum_idx = EGRESS_LINUM_IDX; -static __u32 ingress_linum_idx = INGRESS_LINUM_IDX; +static bool create_netns(void) +{ + if (!ASSERT_OK(unshare(CLONE_NEWNET), "create netns")) + return false; + + if (!ASSERT_OK(system("ip link set dev lo up"), "bring up lo")) + return false; + + return true; +} static void print_sk(const struct bpf_sock *sk, const char *prefix) { @@ -91,19 +102,24 @@ static void check_result(void) { struct bpf_tcp_sock srv_tp, cli_tp, listen_tp; struct bpf_sock srv_sk, cli_sk, listen_sk; - __u32 ingress_linum, egress_linum; + __u32 idx, ingress_linum, egress_linum, linum; int err; - err = bpf_map_lookup_elem(linum_map_fd, &egress_linum_idx, - &egress_linum); + idx = EGRESS_LINUM_IDX; + err = bpf_map_lookup_elem(linum_map_fd, &idx, &egress_linum); CHECK(err < 0, "bpf_map_lookup_elem(linum_map_fd)", "err:%d errno:%d\n", err, errno); - err = bpf_map_lookup_elem(linum_map_fd, &ingress_linum_idx, - &ingress_linum); + idx = INGRESS_LINUM_IDX; + err = bpf_map_lookup_elem(linum_map_fd, &idx, &ingress_linum); CHECK(err < 0, "bpf_map_lookup_elem(linum_map_fd)", "err:%d errno:%d\n", err, errno); + idx = READ_SK_DST_PORT_LINUM_IDX; + err = bpf_map_lookup_elem(linum_map_fd, &idx, &linum); + ASSERT_OK(err, "bpf_map_lookup_elem(linum_map_fd, READ_SK_DST_PORT_IDX)"); + ASSERT_EQ(linum, 0, "failure in read_sk_dst_port on line"); + memcpy(&srv_sk, &skel->bss->srv_sk, sizeof(srv_sk)); memcpy(&srv_tp, &skel->bss->srv_tp, sizeof(srv_tp)); memcpy(&cli_sk, &skel->bss->cli_sk, sizeof(cli_sk)); @@ -262,7 +278,7 @@ static void test(void) char buf[DATA_LEN]; /* Prepare listen_fd */ - listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0); + listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0xcafe, 0); /* start_server() has logged the error details */ if (CHECK_FAIL(listen_fd == -1)) goto done; @@ -330,8 +346,12 @@ static void test(void) void serial_test_sock_fields(void) { - struct bpf_link *egress_link = NULL, *ingress_link = NULL; int parent_cg_fd = -1, child_cg_fd = -1; + struct bpf_link *link; + + /* Use a dedicated netns to have a fixed listen port */ + if (!create_netns()) + return; /* Create a cgroup, get fd, and join it */ parent_cg_fd = test__join_cgroup(PARENT_CGROUP); @@ -352,15 +372,20 @@ void serial_test_sock_fields(void) if (CHECK(!skel, "test_sock_fields__open_and_load", "failed\n")) goto done; - egress_link = bpf_program__attach_cgroup(skel->progs.egress_read_sock_fields, - child_cg_fd); - if (!ASSERT_OK_PTR(egress_link, "attach_cgroup(egress)")) + link = bpf_program__attach_cgroup(skel->progs.egress_read_sock_fields, child_cg_fd); + if (!ASSERT_OK_PTR(link, "attach_cgroup(egress_read_sock_fields)")) + goto done; + skel->links.egress_read_sock_fields = link; + + link = bpf_program__attach_cgroup(skel->progs.ingress_read_sock_fields, child_cg_fd); + if (!ASSERT_OK_PTR(link, "attach_cgroup(ingress_read_sock_fields)")) goto done; + skel->links.ingress_read_sock_fields = link; - ingress_link = bpf_program__attach_cgroup(skel->progs.ingress_read_sock_fields, - child_cg_fd); - if (!ASSERT_OK_PTR(ingress_link, "attach_cgroup(ingress)")) + link = bpf_program__attach_cgroup(skel->progs.read_sk_dst_port, child_cg_fd); + if (!ASSERT_OK_PTR(link, "attach_cgroup(read_sk_dst_port")) goto done; + skel->links.read_sk_dst_port = link; linum_map_fd = bpf_map__fd(skel->maps.linum_map); sk_pkt_out_cnt_fd = bpf_map__fd(skel->maps.sk_pkt_out_cnt); @@ -369,8 +394,7 @@ void serial_test_sock_fields(void) test(); done: - bpf_link__destroy(egress_link); - bpf_link__destroy(ingress_link); + test_sock_fields__detach(skel); test_sock_fields__destroy(skel); if (child_cg_fd >= 0) close(child_cg_fd); diff --git a/tools/testing/selftests/bpf/progs/test_sock_fields.c b/tools/testing/selftests/bpf/progs/test_sock_fields.c index 81b57b9aaaea..246f1f001813 100644 --- a/tools/testing/selftests/bpf/progs/test_sock_fields.c +++ b/tools/testing/selftests/bpf/progs/test_sock_fields.c @@ -12,6 +12,7 @@ enum bpf_linum_array_idx { EGRESS_LINUM_IDX, INGRESS_LINUM_IDX, + READ_SK_DST_PORT_LINUM_IDX, __NR_BPF_LINUM_ARRAY_IDX, }; @@ -250,4 +251,44 @@ int ingress_read_sock_fields(struct __sk_buff *skb) return CG_OK; } +static __noinline bool sk_dst_port__load_word(struct bpf_sock *sk) +{ + __u32 *word = (__u32 *)&sk->dst_port; + return word[0] == bpf_htonl(0xcafe0000); +} + +static __noinline bool sk_dst_port__load_half(struct bpf_sock *sk) +{ + __u16 *half = (__u16 *)&sk->dst_port; + return half[0] == bpf_htons(0xcafe); +} + +static __noinline bool sk_dst_port__load_byte(struct bpf_sock *sk) +{ + __u8 *byte = (__u8 *)&sk->dst_port; + return byte[0] == 0xca && byte[1] == 0xfe; +} + +SEC("cgroup_skb/egress") +int read_sk_dst_port(struct __sk_buff *skb) +{ + __u32 linum, linum_idx; + struct bpf_sock *sk; + + linum_idx = READ_SK_DST_PORT_LINUM_IDX; + + sk = skb->sk; + if (!sk) + RET_LOG(); + + if (!sk_dst_port__load_word(sk)) + RET_LOG(); + if (!sk_dst_port__load_half(sk)) + RET_LOG(); + if (!sk_dst_port__load_byte(sk)) + RET_LOG(); + + return CG_OK; +} + char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/verifier/sock.c b/tools/testing/selftests/bpf/verifier/sock.c index ce13ece08d51..8c224eac93df 100644 --- a/tools/testing/selftests/bpf/verifier/sock.c +++ b/tools/testing/selftests/bpf/verifier/sock.c @@ -121,7 +121,25 @@ .result = ACCEPT, }, { - "sk_fullsock(skb->sk): sk->dst_port [narrow load]", + "sk_fullsock(skb->sk): sk->dst_port [word load] (backward compatibility)", + .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_EMIT_CALL(BPF_FUNC_sk_fullsock), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, dst_port)), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + .result = ACCEPT, +}, +{ + "sk_fullsock(skb->sk): sk->dst_port [half load]", .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), @@ -139,7 +157,64 @@ .result = ACCEPT, }, { - "sk_fullsock(skb->sk): sk->dst_port [load 2nd byte]", + "sk_fullsock(skb->sk): sk->dst_port [half load] (invalid)", + .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_EMIT_CALL(BPF_FUNC_sk_fullsock), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, dst_port) + 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + .result = REJECT, + .errstr = "invalid sock access", +}, +{ + "sk_fullsock(skb->sk): sk->dst_port [byte load]", + .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_EMIT_CALL(BPF_FUNC_sk_fullsock), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_LDX_MEM(BPF_B, BPF_REG_2, BPF_REG_0, offsetof(struct bpf_sock, dst_port)), + BPF_LDX_MEM(BPF_B, BPF_REG_2, BPF_REG_0, offsetof(struct bpf_sock, dst_port) + 1), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + .result = ACCEPT, +}, +{ + "sk_fullsock(skb->sk): sk->dst_port [byte load] (invalid)", + .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_EMIT_CALL(BPF_FUNC_sk_fullsock), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, dst_port) + 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_CGROUP_SKB, + .result = REJECT, + .errstr = "invalid sock access", +}, +{ + "sk_fullsock(skb->sk): past sk->dst_port [half load] (invalid)", .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), @@ -149,7 +224,7 @@ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 2), BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), - BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_0, offsetof(struct bpf_sock, dst_port) + 1), + BPF_LDX_MEM(BPF_H, BPF_REG_0, BPF_REG_0, offsetofend(struct bpf_sock, dst_port)), BPF_MOV64_IMM(BPF_REG_0, 0), BPF_EXIT_INSN(), },