From patchwork Fri Jun 28 23:10:48 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 1124606 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="G1HGo98N"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45bCDb3sz9z9s5c for ; Sat, 29 Jun 2019 09:10:54 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726787AbfF1XKx (ORCPT ); Fri, 28 Jun 2019 19:10:53 -0400 Received: from mail-pg1-f202.google.com ([209.85.215.202]:45195 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726631AbfF1XKx (ORCPT ); Fri, 28 Jun 2019 19:10:53 -0400 Received: by mail-pg1-f202.google.com with SMTP id n7so3900836pgr.12 for ; Fri, 28 Jun 2019 16:10:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=H1uw8GNHqdne1YqmW30hQmg7ehvjJ07bgavin0v97FA=; b=G1HGo98N06/C96ASXTRQ8Z8DwfpQ4rC88TZvh6R7AuL8Bb0uMCA64FgFwfWI2OrlW/ 5ZYxVu3fBdgzsYk082oSaxiDQ7WI6m7GR2IhKVgd296VQNlZa+BcFhDzjqyLQLnd0w+L M57d/1psVlxo/oszPG70J9CMX+jmcJJ2gLUQvTiB6ip2Q+CvmJTQGqXLGB1ixAhRqUKT F3Mr4ZAHddLFcizilTx9AAtfz2fjcweEKNNWvgfpTQFGZe7ni46zS41PKUYchuqyinH6 pRRYoYS+1iYxRq1UBr2W3VIwYAixrTKZoj1rPtrdgkeHvlKwALMvpzQHM+axZXLsgE9q U8OQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=H1uw8GNHqdne1YqmW30hQmg7ehvjJ07bgavin0v97FA=; b=fiepx2xy9OHibjsygJj2kmd3eD9eMjbv9v8hxfCsoBdtfA52iKDDY5IlKELQORkz9u Ex47FBcg1+M8BBBhV2uJa6SBChri2Rg7F3PgrrygQUOXKHIqjwGPxxcgAES+vHUPxFNe wfk1SiF30KEh7JuDlEty4QTERkx/qhe/d/dZPhRfX3Q89hbO6MVlPfGliGUIKha059Np q1UadxxWBmjfp/7Q707pGmyWRFjOSM10eIthasXND6Yh9teYqzO0rwBr+vdoXVfef3EG x3sz8hDkpAZDWGTMSHCqHxLWyKXEu24yUuXD78QRvDddrntmV0WN8h/LxVG3Pcij7nnm dT0g== X-Gm-Message-State: APjAAAXSc4uPs5au0QqKC2DsxXAg1KMBv+ZMWCbpk36cwSyOxFGN/WyM mWcJOIQt9di2LKsVJHO9+RiOKYv/WDSBvoR8/IAAcGuOrOSiTE05nLL/YcY/CTj/6oOd1b39flL zyfEPZYAWO0SopxZCv3B28jWYoR9Uk7RMs8ql3ZVdOn3Qfn/4GuImgQ== X-Google-Smtp-Source: APXvYqzn1y/EUNmYcU6bEtZmjhaAhzm9/gCbpGaC5ql1JodiKRqRZXv/A3SZQLptiFW84eM3ykNpngA= X-Received: by 2002:a63:a61:: with SMTP id z33mr11668815pgk.154.1561763451833; Fri, 28 Jun 2019 16:10:51 -0700 (PDT) Date: Fri, 28 Jun 2019 16:10:48 -0700 Message-Id: <20190628231049.22149-1-sdf@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH bpf-next 1/2] bpf: allow wide (u64) aligned stores for some fields of bpf_sock_addr From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev , Andrii Nakryiko , Yonghong Song , kernel test robot Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Since commit cd17d7770578 ("bpf/tools: sync bpf.h") clang decided that it can do a single u64 store into user_ip6[2] instead of two separate u32 ones: # 17: (18) r2 = 0x100000000000000 # ; ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_2); # 19: (7b) *(u64 *)(r1 +16) = r2 # invalid bpf_context access off=16 size=8 From the compiler point of view it does look like a correct thing to do, so let's support it on the kernel side. Credit to Andrii Nakryiko for a proper implementation of bpf_ctx_wide_store_ok. Cc: Andrii Nakryiko Cc: Yonghong Song Fixes: cd17d7770578 ("bpf/tools: sync bpf.h") Reported-by: kernel test robot Signed-off-by: Stanislav Fomichev Acked-by: Yonghong Song Acked-by: Andrii Nakryiko --- include/linux/filter.h | 6 ++++++ net/core/filter.c | 22 ++++++++++++++-------- 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/include/linux/filter.h b/include/linux/filter.h index 340f7d648974..3901007e36f1 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -746,6 +746,12 @@ bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default) return size <= size_default && (size & (size - 1)) == 0; } +#define bpf_ctx_wide_store_ok(off, size, type, field) \ + (size == sizeof(__u64) && \ + off >= offsetof(type, field) && \ + off + sizeof(__u64) <= offsetofend(type, field) && \ + off % sizeof(__u64) == 0) + #define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0])) static inline void bpf_prog_lock_ro(struct bpf_prog *fp) diff --git a/net/core/filter.c b/net/core/filter.c index dc8534be12fc..5d33f2146dab 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -6849,6 +6849,16 @@ static bool sock_addr_is_valid_access(int off, int size, if (!bpf_ctx_narrow_access_ok(off, size, size_default)) return false; } else { + if (bpf_ctx_wide_store_ok(off, size, + struct bpf_sock_addr, + user_ip6)) + return true; + + if (bpf_ctx_wide_store_ok(off, size, + struct bpf_sock_addr, + msg_src_ip6)) + return true; + if (size != size_default) return false; } @@ -7689,9 +7699,6 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, /* SOCK_ADDR_STORE_NESTED_FIELD_OFF() has semantic similar to * SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF() but for store operation. * - * It doesn't support SIZE argument though since narrow stores are not - * supported for now. - * * In addition it uses Temporary Field TF (member of struct S) as the 3rd * "register" since two registers available in convert_ctx_access are not * enough: we can't override neither SRC, since it contains value to store, nor @@ -7699,7 +7706,7 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, * instructions. But we need a temporary place to save pointer to nested * structure whose field we want to store to. */ -#define SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, OFF, TF) \ +#define SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, SIZE, OFF, TF) \ do { \ int tmp_reg = BPF_REG_9; \ if (si->src_reg == tmp_reg || si->dst_reg == tmp_reg) \ @@ -7710,8 +7717,7 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, offsetof(S, TF)); \ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(S, F), tmp_reg, \ si->dst_reg, offsetof(S, F)); \ - *insn++ = BPF_STX_MEM( \ - BPF_FIELD_SIZEOF(NS, NF), tmp_reg, si->src_reg, \ + *insn++ = BPF_STX_MEM(SIZE, tmp_reg, si->src_reg, \ bpf_target_off(NS, NF, FIELD_SIZEOF(NS, NF), \ target_size) \ + OFF); \ @@ -7723,8 +7729,8 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, TF) \ do { \ if (type == BPF_WRITE) { \ - SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, OFF, \ - TF); \ + SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, SIZE, \ + OFF, TF); \ } else { \ SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF( \ S, NS, F, NF, SIZE, OFF); \ From patchwork Fri Jun 28 23:10:49 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 1124608 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="nOi62sK3"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 45bCDc4Jbvz9sBb for ; Sat, 29 Jun 2019 09:10:56 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726809AbfF1XKz (ORCPT ); Fri, 28 Jun 2019 19:10:55 -0400 Received: from mail-pl1-f202.google.com ([209.85.214.202]:37791 "EHLO mail-pl1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726631AbfF1XKz (ORCPT ); Fri, 28 Jun 2019 19:10:55 -0400 Received: by mail-pl1-f202.google.com with SMTP id w14so4317331plp.4 for ; Fri, 28 Jun 2019 16:10:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=NgrRIARcyMWOir0ruPBISSB6ahNutZuUALDllPdbWtc=; b=nOi62sK3W7g/Z1kdRAEpN2WpY2rn/vUB+2aUGV76qht9s6DWtapkyO2YaBmeKtS7hh JQb63Go+5ZoglL7v08ZbPk59nzQWTA36HsJrA1NCDaYyyq+6ZUq707YGyAQD0n55BWTl U+nZBG5nA/EWKIj0nD73P83Gvf6cQpQA3sfPKck6dh5KCsrZeJEFBw4LvGXd7hzrzLdZ 0tytf6emNHqur/94NXiS3iTX5wySniX1hK0EH5H4UB/23IlfYnqssVRgiuz+ikdopxqR ZpdBBrO98275SoXZv1Pb7OstAbuPStp08csWV+q/ri6JEXU3jzZkXPpKvwh0Dv0TljOV qMwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=NgrRIARcyMWOir0ruPBISSB6ahNutZuUALDllPdbWtc=; b=EQa/bK8iYFsQvVQAuuOV8+Se224q8lPk+jRxfzZYTIKwQUoAWFwMhhxGza8QRO75Lv Ua9BuIU4BgQ2sM2ixovJcE0Dj2uj1oL0JlxxYMhpssaTJeog5f8Pr+i0WYNBs3hbnjQT hCuAndgqirf+zW7vALxtRZ/lWu75fCEQwJRtUBNJ1XkWj3r38To3v7X9NeMII7TLgzZb 8HSwT0Bb0taxD306hIG42zMsy1KGUVCMwIuFz5HfG37q8IPEqB6v9qgPja5BTqUBgOMC R6Em9UQGBwngeJanJkvlmYRDyQ+7UiL0rIhfGmRvnyzXCEdm7ju9VR6CW2phECZJk7WZ dlBA== X-Gm-Message-State: APjAAAU+weWw77Yab4qmNiYqMdJGDHAx+XpxAbG2z0oXmEtEcVkT/dtO cOyihUcke8q4VgjSOOwB6mmLGDk= X-Google-Smtp-Source: APXvYqxl7zrL/BNrQspBBaD6a+tszMiVgWXXfRGmbb1ELsvO2mUrZn/ykq8q8MKu44I0HU1kA9v/e4o= X-Received: by 2002:a65:500d:: with SMTP id f13mr11361343pgo.151.1561763454299; Fri, 28 Jun 2019 16:10:54 -0700 (PDT) Date: Fri, 28 Jun 2019 16:10:49 -0700 In-Reply-To: <20190628231049.22149-1-sdf@google.com> Message-Id: <20190628231049.22149-2-sdf@google.com> Mime-Version: 1.0 References: <20190628231049.22149-1-sdf@google.com> X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH bpf-next 2/2] selftests/bpf: add verifier tests for wide stores From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev , Andrii Nakryiko , Yonghong Song Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Make sure that wide stores are allowed at proper (aligned) addresses. Note that user_ip6 is naturally aligned on 8-byte boundary, so correct addresses are user_ip6[0] and user_ip6[2]. msg_src_ip6 is, however, aligned on a 4-byte bondary, so only msg_src_ip6[1] can be wide-stored. Cc: Andrii Nakryiko Cc: Yonghong Song Signed-off-by: Stanislav Fomichev --- tools/testing/selftests/bpf/test_verifier.c | 17 ++++++-- .../selftests/bpf/verifier/wide_store.c | 40 +++++++++++++++++++ 2 files changed, 54 insertions(+), 3 deletions(-) create mode 100644 tools/testing/selftests/bpf/verifier/wide_store.c diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index c5514daf8865..b0773291012a 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -105,6 +105,7 @@ struct bpf_test { __u64 data64[TEST_DATA_LEN / 8]; }; } retvals[MAX_TEST_RUNS]; + enum bpf_attach_type expected_attach_type; }; /* Note we want this to be 64 bit aligned so that the end of our array is @@ -850,6 +851,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv, int fd_prog, expected_ret, alignment_prevented_execution; int prog_len, prog_type = test->prog_type; struct bpf_insn *prog = test->insns; + struct bpf_load_program_attr attr; int run_errs, run_successes; int map_fds[MAX_NR_MAPS]; const char *expected_err; @@ -881,8 +883,17 @@ static void do_test_single(struct bpf_test *test, bool unpriv, pflags |= BPF_F_STRICT_ALIGNMENT; if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS) pflags |= BPF_F_ANY_ALIGNMENT; - fd_prog = bpf_verify_program(prog_type, prog, prog_len, pflags, - "GPL", 0, bpf_vlog, sizeof(bpf_vlog), 4); + + memset(&attr, 0, sizeof(attr)); + attr.prog_type = prog_type; + attr.expected_attach_type = test->expected_attach_type; + attr.insns = prog; + attr.insns_cnt = prog_len; + attr.license = "GPL"; + attr.log_level = 4; + attr.prog_flags = pflags; + + fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog)); if (fd_prog < 0 && !bpf_probe_prog_type(prog_type, 0)) { printf("SKIP (unsupported program type %d)\n", prog_type); skips++; @@ -912,7 +923,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv, printf("FAIL\nUnexpected success to load!\n"); goto fail_log; } - if (!strstr(bpf_vlog, expected_err)) { + if (!expected_err || !strstr(bpf_vlog, expected_err)) { printf("FAIL\nUnexpected error message!\n\tEXP: %s\n\tRES: %s\n", expected_err, bpf_vlog); goto fail_log; diff --git a/tools/testing/selftests/bpf/verifier/wide_store.c b/tools/testing/selftests/bpf/verifier/wide_store.c new file mode 100644 index 000000000000..c6385f45b114 --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/wide_store.c @@ -0,0 +1,40 @@ +#define BPF_SOCK_ADDR(field, off, res, err) \ +{ \ + "wide store to bpf_sock_addr." #field "[" #off "]", \ + .insns = { \ + BPF_MOV64_IMM(BPF_REG_0, 1), \ + BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, \ + offsetof(struct bpf_sock_addr, field[off])), \ + BPF_EXIT_INSN(), \ + }, \ + .result = res, \ + .prog_type = BPF_PROG_TYPE_CGROUP_SOCK_ADDR, \ + .expected_attach_type = BPF_CGROUP_UDP6_SENDMSG, \ + .errstr = err, \ +} + +/* user_ip6[0] is u64 aligned */ +BPF_SOCK_ADDR(user_ip6, 0, ACCEPT, + NULL), +BPF_SOCK_ADDR(user_ip6, 1, REJECT, + "invalid bpf_context access off=12 size=8"), +BPF_SOCK_ADDR(user_ip6, 2, ACCEPT, + NULL), +BPF_SOCK_ADDR(user_ip6, 3, REJECT, + "invalid bpf_context access off=20 size=8"), +BPF_SOCK_ADDR(user_ip6, 4, REJECT, + "invalid bpf_context access off=24 size=8"), + +/* msg_src_ip6[0] is _not_ u64 aligned */ +BPF_SOCK_ADDR(msg_src_ip6, 0, REJECT, + "invalid bpf_context access off=44 size=8"), +BPF_SOCK_ADDR(msg_src_ip6, 1, ACCEPT, + NULL), +BPF_SOCK_ADDR(msg_src_ip6, 2, REJECT, + "invalid bpf_context access off=52 size=8"), +BPF_SOCK_ADDR(msg_src_ip6, 3, REJECT, + "invalid bpf_context access off=56 size=8"), +BPF_SOCK_ADDR(msg_src_ip6, 4, REJECT, + "invalid bpf_context access off=60 size=8"), + +#undef BPF_SOCK_ADDR