From patchwork Tue Oct 2 20:35:38 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joe Stringer X-Patchwork-Id: 978022 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=none (p=none dis=none) header.from=wand.net.nz Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="ig11KGDo"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42PrX26dylz9s3C for ; Wed, 3 Oct 2018 06:36:02 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727747AbeJCDVK (ORCPT ); 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bh=GJV0D1ZgjnBzlvXRpcRe7U03JgSSuAd5Vy3RD4qQ49k=; b=snaWHmxx5gybsludDAqkl6pITVUWZLVkkGMB/SoFAOb5/iDiygOlrsWwsTmeFeHPD+ zG4W/JxqsqokOg38h3TH0aN4D8jrRVjwUcZlbbl5bi9V/tSvbuTfkE0v8oUg5HzGDOkY Jytk1iyJpZasR+ZGxuyr6eQv8ZoM3TRS+9OC4Vk0lIh+wzoyyleTfj+DAJB3jlzwjMFu FZNKIXhQv7n+TJWCSgRFJEa+Kx7s9mRaGtQK+/75ZHRnu2/M7k3vTh53vsp2DTegdPxQ 9TOGTKSWiaQ1UAhbpTBjxAXKoJTqB25kpjEoMiCyq60x6PfAHGYbphDXSO3HbjxvoSPD 7wRw== X-Gm-Message-State: ABuFfohN6hqwEteTjF2+qCwOTyjNCam+zJuxywLMz6V+TycDeB6MDakK /5XQA3cHM1Ux0e6Xo+rtLN4= X-Google-Smtp-Source: ACcGV63l/WXUuvzABYyB71anP4dru7LtjHgsWqcKFo4GIpzqkO7wcGBS+Z3XR+9V9DYFcuTtGdwd0Q== X-Received: by 2002:a5b:7c1:: with SMTP id t1-v6mr1735246ybq.324.1538512559555; Tue, 02 Oct 2018 13:35:59 -0700 (PDT) Received: from localhost.localdomain ([99.0.85.34]) by smtp.gmail.com with ESMTPSA id o131-v6sm4555361ywb.107.2018.10.02.13.35.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 02 Oct 2018 13:35:59 -0700 (PDT) From: Joe Stringer To: daniel@iogearbox.net Cc: netdev@vger.kernel.org, ast@kernel.org, john.fastabend@gmail.com, tgraf@suug.ch, kafai@fb.com, nitin.hande@gmail.com, mauricio.vasquez@polito.it Subject: [PATCHv4 bpf-next 10/13] selftests/bpf: Add tests for reference tracking Date: Tue, 2 Oct 2018 13:35:38 -0700 Message-Id: <20181002203541.26599-11-joe@wand.net.nz> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181002203541.26599-1-joe@wand.net.nz> References: <20181002203541.26599-1-joe@wand.net.nz> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org reference tracking: leak potential reference reference tracking: leak potential reference on stack reference tracking: leak potential reference on stack 2 reference tracking: zero potential reference reference tracking: copy and zero potential references reference tracking: release reference without check reference tracking: release reference reference tracking: release reference twice reference tracking: release reference twice inside branch reference tracking: alloc, check, free in one subbranch reference tracking: alloc, check, free in both subbranches reference tracking in call: free reference in subprog reference tracking in call: free reference in subprog and outside reference tracking in call: alloc & leak reference in subprog reference tracking in call: alloc in subprog, release outside reference tracking in call: sk_ptr leak into caller stack reference tracking in call: sk_ptr spill into caller stack reference tracking: allow LD_ABS reference tracking: forbid LD_ABS while holding reference reference tracking: allow LD_IND reference tracking: forbid LD_IND while holding reference reference tracking: check reference or tail call reference tracking: release reference then tail call reference tracking: leak possible reference over tail call reference tracking: leak checked reference over tail call reference tracking: mangle and release sock_or_null reference tracking: mangle and release sock reference tracking: access member reference tracking: write to member reference tracking: invalid 64-bit access of member reference tracking: access after release reference tracking: direct access for lookup unpriv: spill/fill of different pointers stx - ctx and sock unpriv: spill/fill of different pointers stx - leak sock unpriv: spill/fill of different pointers stx - sock and ctx (read) unpriv: spill/fill of different pointers stx - sock and ctx (write) Signed-off-by: Joe Stringer --- v3: Rebase against bpf_sk_release() flags argument removal. Removed Alexei's ack since there are many new tests: * "reference tracking: allow LD_ABS", * "reference tracking: forbid LD_ABS while holding reference", * "reference tracking: allow LD_IND", * "reference tracking: forbid LD_IND while holding reference", * "reference tracking: check reference or tail call", * "reference tracking: release reference then tail call", * "reference tracking: leak possible reference over tail call", * "reference tracking: leak checked reference over tail call", * "reference tracking: mangle and release sock_or_null", * "reference tracking: mangle and release sock", * "reference tracking: access member", * "reference tracking: write to member", * "reference tracking: invalid 64-bit access of member", * "reference tracking: access after release", * "reference tracking: direct access for lookup", v4: New tests: * unpriv: spill/fill of different pointers stx - ctx and sock * unpriv: spill/fill of different pointers stx - leak sock * unpriv: spill/fill of different pointers stx - sock and ctx (read) * unpriv: spill/fill of different pointers stx - sock and ctx (write) --- tools/testing/selftests/bpf/test_verifier.c | 759 ++++++++++++++++++++ 1 file changed, 759 insertions(+) diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c index 163fd1c0062c..bc9cd8537467 100644 --- a/tools/testing/selftests/bpf/test_verifier.c +++ b/tools/testing/selftests/bpf/test_verifier.c @@ -3,6 +3,7 @@ * * Copyright (c) 2014 PLUMgrid, http://plumgrid.com * Copyright (c) 2017 Facebook + * Copyright (c) 2018 Covalent IO, Inc. http://covalent.io * * This program is free software; you can redistribute it and/or * modify it under the terms of version 2 of the GNU General Public @@ -178,6 +179,24 @@ static void bpf_fill_rand_ld_dw(struct bpf_test *self) self->retval = (uint32_t)res; } +/* BPF_SK_LOOKUP contains 13 instructions, if you need to fix up maps */ +#define BPF_SK_LOOKUP \ + /* struct bpf_sock_tuple tuple = {} */ \ + BPF_MOV64_IMM(BPF_REG_2, 0), \ + BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_2, -8), \ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -16), \ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -24), \ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -32), \ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -40), \ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_2, -48), \ + /* sk = sk_lookup_tcp(ctx, &tuple, sizeof tuple, 0, 0) */ \ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), \ + BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -48), \ + BPF_MOV64_IMM(BPF_REG_3, sizeof(struct bpf_sock_tuple)), \ + BPF_MOV64_IMM(BPF_REG_4, 0), \ + BPF_MOV64_IMM(BPF_REG_5, 0), \ + BPF_EMIT_CALL(BPF_FUNC_sk_lookup_tcp) + static struct bpf_test tests[] = { { "add+sub+mul", @@ -2707,6 +2726,137 @@ static struct bpf_test tests[] = { .errstr = "same insn cannot be used with different pointers", .prog_type = BPF_PROG_TYPE_SCHED_CLS, }, + { + "unpriv: spill/fill of different pointers stx - ctx and sock", + .insns = { + BPF_MOV64_REG(BPF_REG_8, BPF_REG_1), + /* struct bpf_sock *sock = bpf_sock_lookup(...); */ + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + /* u64 foo; */ + /* void *target = &foo; */ + BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + /* if (skb == NULL) *target = sock; */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0), + /* else *target = skb; */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0), + /* struct __sk_buff *skb = *target; */ + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0), + /* skb->mark = 42; */ + BPF_MOV64_IMM(BPF_REG_3, 42), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, + offsetof(struct __sk_buff, mark)), + /* if (sk) bpf_sk_release(sk) */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "type=ctx expected=sock", + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + }, + { + "unpriv: spill/fill of different pointers stx - leak sock", + .insns = { + BPF_MOV64_REG(BPF_REG_8, BPF_REG_1), + /* struct bpf_sock *sock = bpf_sock_lookup(...); */ + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + /* u64 foo; */ + /* void *target = &foo; */ + BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + /* if (skb == NULL) *target = sock; */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0), + /* else *target = skb; */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0), + /* struct __sk_buff *skb = *target; */ + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0), + /* skb->mark = 42; */ + BPF_MOV64_IMM(BPF_REG_3, 42), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, + offsetof(struct __sk_buff, mark)), + BPF_EXIT_INSN(), + }, + .result = REJECT, + //.errstr = "same insn cannot be used with different pointers", + .errstr = "Unreleased reference", + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + }, + { + "unpriv: spill/fill of different pointers stx - sock and ctx (read)", + .insns = { + BPF_MOV64_REG(BPF_REG_8, BPF_REG_1), + /* struct bpf_sock *sock = bpf_sock_lookup(...); */ + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + /* u64 foo; */ + /* void *target = &foo; */ + BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + /* if (skb) *target = skb */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0), + /* else *target = sock */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0), + /* struct bpf_sock *sk = *target; */ + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0), + /* if (sk) u32 foo = sk->mark; bpf_sk_release(sk); */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 2), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct bpf_sock, mark)), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + .errstr = "same insn cannot be used with different pointers", + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + }, + { + "unpriv: spill/fill of different pointers stx - sock and ctx (write)", + .insns = { + BPF_MOV64_REG(BPF_REG_8, BPF_REG_1), + /* struct bpf_sock *sock = bpf_sock_lookup(...); */ + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_2, BPF_REG_0), + /* u64 foo; */ + /* void *target = &foo; */ + BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_6, -8), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_8), + /* if (skb) *target = skb */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_1, 0), + /* else *target = sock */ + BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 1), + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_2, 0), + /* struct bpf_sock *sk = *target; */ + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_6, 0), + /* if (sk) sk->mark = 42; bpf_sk_release(sk); */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 3), + BPF_MOV64_IMM(BPF_REG_3, 42), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_3, + offsetof(struct bpf_sock, mark)), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .result = REJECT, + //.errstr = "same insn cannot be used with different pointers", + .errstr = "cannot write into socket", + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + }, { "unpriv: spill/fill of different pointers ldx", .insns = { @@ -12557,6 +12707,214 @@ static struct bpf_test tests[] = { .prog_type = BPF_PROG_TYPE_SCHED_CLS, .result = ACCEPT, }, + { + "reference tracking: leak potential reference", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), /* leak reference */ + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "Unreleased reference", + .result = REJECT, + }, + { + "reference tracking: leak potential reference on stack", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_4, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "Unreleased reference", + .result = REJECT, + }, + { + "reference tracking: leak potential reference on stack 2", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_4, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_ST_MEM(BPF_DW, BPF_REG_4, 0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "Unreleased reference", + .result = REJECT, + }, + { + "reference tracking: zero potential reference", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_IMM(BPF_REG_0, 0), /* leak reference */ + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "Unreleased reference", + .result = REJECT, + }, + { + "reference tracking: copy and zero potential references", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_7, BPF_REG_0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_MOV64_IMM(BPF_REG_7, 0), /* leak reference */ + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "Unreleased reference", + .result = REJECT, + }, + { + "reference tracking: release reference without check", + .insns = { + BPF_SK_LOOKUP, + /* reference in r0 may be NULL */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "type=sock_or_null expected=sock", + .result = REJECT, + }, + { + "reference tracking: release reference", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "reference tracking: release reference 2", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), + BPF_EXIT_INSN(), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "reference tracking: release reference twice", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "type=inv expected=sock", + .result = REJECT, + }, + { + "reference tracking: release reference twice inside branch", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), /* goto end */ + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "type=inv expected=sock", + .result = REJECT, + }, + { + "reference tracking: alloc, check, free in one subbranch", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, data)), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct __sk_buff, data_end)), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 16), + /* if (offsetof(skb, mark) > data_len) exit; */ + BPF_JMP_REG(BPF_JLE, BPF_REG_0, BPF_REG_3, 1), + BPF_EXIT_INSN(), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_2, + offsetof(struct __sk_buff, mark)), + BPF_SK_LOOKUP, + BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 1), /* mark == 0? */ + /* Leak reference in R0 */ + BPF_EXIT_INSN(), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), /* sk NULL? */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "Unreleased reference", + .result = REJECT, + }, + { + "reference tracking: alloc, check, free in both subbranches", + .insns = { + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, data)), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct __sk_buff, data_end)), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 16), + /* if (offsetof(skb, mark) > data_len) exit; */ + BPF_JMP_REG(BPF_JLE, BPF_REG_0, BPF_REG_3, 1), + BPF_EXIT_INSN(), + BPF_LDX_MEM(BPF_W, BPF_REG_6, BPF_REG_2, + offsetof(struct __sk_buff, mark)), + BPF_SK_LOOKUP, + BPF_JMP_IMM(BPF_JEQ, BPF_REG_6, 0, 4), /* mark == 0? */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), /* sk NULL? */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), /* sk NULL? */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "reference tracking in call: free reference in subprog", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), /* unchecked reference */ + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + + /* subprog 1 */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_1), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, { "pass modified ctx pointer to helper, 1", .insns = { @@ -12627,6 +12985,407 @@ static struct bpf_test tests[] = { .prog_type = BPF_PROG_TYPE_SCHED_CLS, .result = ACCEPT, }, + { + "reference tracking in call: free reference in subprog and outside", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), /* unchecked reference */ + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 3), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + + /* subprog 1 */ + BPF_MOV64_REG(BPF_REG_2, BPF_REG_1), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_2, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "type=inv expected=sock", + .result = REJECT, + }, + { + "reference tracking in call: alloc & leak reference in subprog", + .insns = { + BPF_MOV64_REG(BPF_REG_4, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 3), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + + /* subprog 1 */ + BPF_MOV64_REG(BPF_REG_6, BPF_REG_4), + BPF_SK_LOOKUP, + /* spill unchecked sk_ptr into stack of caller */ + BPF_STX_MEM(BPF_DW, BPF_REG_6, BPF_REG_0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "Unreleased reference", + .result = REJECT, + }, + { + "reference tracking in call: alloc in subprog, release outside", + .insns = { + BPF_MOV64_REG(BPF_REG_4, BPF_REG_10), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 4), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + + /* subprog 1 */ + BPF_SK_LOOKUP, + BPF_EXIT_INSN(), /* return sk */ + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .retval = POINTER_VALUE, + .result = ACCEPT, + }, + { + "reference tracking in call: sk_ptr leak into caller stack", + .insns = { + BPF_MOV64_REG(BPF_REG_4, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + + /* subprog 1 */ + BPF_MOV64_REG(BPF_REG_5, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 5), + /* spill unchecked sk_ptr into stack of caller */ + BPF_MOV64_REG(BPF_REG_5, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8), + BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_5, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0), + BPF_EXIT_INSN(), + + /* subprog 2 */ + BPF_SK_LOOKUP, + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "Unreleased reference", + .result = REJECT, + }, + { + "reference tracking in call: sk_ptr spill into caller stack", + .insns = { + BPF_MOV64_REG(BPF_REG_4, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + + /* subprog 1 */ + BPF_MOV64_REG(BPF_REG_5, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8), + BPF_STX_MEM(BPF_DW, BPF_REG_5, BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 1, 0, 8), + /* spill unchecked sk_ptr into stack of caller */ + BPF_MOV64_REG(BPF_REG_5, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_5, -8), + BPF_LDX_MEM(BPF_DW, BPF_REG_4, BPF_REG_5, 0), + BPF_STX_MEM(BPF_DW, BPF_REG_4, BPF_REG_0, 0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + /* now the sk_ptr is verified, free the reference */ + BPF_LDX_MEM(BPF_DW, BPF_REG_1, BPF_REG_4, 0), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + + /* subprog 2 */ + BPF_SK_LOOKUP, + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "reference tracking: allow LD_ABS", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_LD_ABS(BPF_B, 0), + BPF_LD_ABS(BPF_H, 0), + BPF_LD_ABS(BPF_W, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "reference tracking: forbid LD_ABS while holding reference", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_SK_LOOKUP, + BPF_LD_ABS(BPF_B, 0), + BPF_LD_ABS(BPF_H, 0), + BPF_LD_ABS(BPF_W, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "BPF_LD_[ABS|IND] cannot be mixed with socket references", + .result = REJECT, + }, + { + "reference tracking: allow LD_IND", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_MOV64_IMM(BPF_REG_7, 1), + BPF_LD_IND(BPF_W, BPF_REG_7, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_7), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + .retval = 1, + }, + { + "reference tracking: forbid LD_IND while holding reference", + .insns = { + BPF_MOV64_REG(BPF_REG_6, BPF_REG_1), + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_4, BPF_REG_0), + BPF_MOV64_IMM(BPF_REG_7, 1), + BPF_LD_IND(BPF_W, BPF_REG_7, -0x200000), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_7), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_4), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "BPF_LD_[ABS|IND] cannot be mixed with socket references", + .result = REJECT, + }, + { + "reference tracking: check reference or tail call", + .insns = { + BPF_MOV64_REG(BPF_REG_7, BPF_REG_1), + BPF_SK_LOOKUP, + /* if (sk) bpf_sk_release() */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_1, 0, 7), + /* bpf_tail_call() */ + BPF_MOV64_IMM(BPF_REG_3, 2), + BPF_LD_MAP_FD(BPF_REG_2, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_7), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_tail_call), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .fixup_prog1 = { 17 }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "reference tracking: release reference then tail call", + .insns = { + BPF_MOV64_REG(BPF_REG_7, BPF_REG_1), + BPF_SK_LOOKUP, + /* if (sk) bpf_sk_release() */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + /* bpf_tail_call() */ + BPF_MOV64_IMM(BPF_REG_3, 2), + BPF_LD_MAP_FD(BPF_REG_2, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_7), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_tail_call), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .fixup_prog1 = { 18 }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "reference tracking: leak possible reference over tail call", + .insns = { + BPF_MOV64_REG(BPF_REG_7, BPF_REG_1), + /* Look up socket and store in REG_6 */ + BPF_SK_LOOKUP, + /* bpf_tail_call() */ + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_MOV64_IMM(BPF_REG_3, 2), + BPF_LD_MAP_FD(BPF_REG_2, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_7), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_tail_call), + BPF_MOV64_IMM(BPF_REG_0, 0), + /* if (sk) bpf_sk_release() */ + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_1, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .fixup_prog1 = { 16 }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "tail_call would lead to reference leak", + .result = REJECT, + }, + { + "reference tracking: leak checked reference over tail call", + .insns = { + BPF_MOV64_REG(BPF_REG_7, BPF_REG_1), + /* Look up socket and store in REG_6 */ + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + /* if (!sk) goto end */ + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 7), + /* bpf_tail_call() */ + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_LD_MAP_FD(BPF_REG_2, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_7), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, + BPF_FUNC_tail_call), + BPF_MOV64_IMM(BPF_REG_0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .fixup_prog1 = { 17 }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "tail_call would lead to reference leak", + .result = REJECT, + }, + { + "reference tracking: mangle and release sock_or_null", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 5), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 1), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "R1 pointer arithmetic on sock_or_null prohibited", + .result = REJECT, + }, + { + "reference tracking: mangle and release sock", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, 5), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "R1 pointer arithmetic on sock prohibited", + .result = REJECT, + }, + { + "reference tracking: access member", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_0, 4), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, + { + "reference tracking: write to member", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 5), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_LD_IMM64(BPF_REG_2, 42), + BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_2, + offsetof(struct bpf_sock, mark)), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_LD_IMM64(BPF_REG_0, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "cannot write into socket", + .result = REJECT, + }, + { + "reference tracking: invalid 64-bit access of member", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_LDX_MEM(BPF_DW, BPF_REG_2, BPF_REG_0, 0), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "invalid bpf_sock access off=0 size=8", + .result = REJECT, + }, + { + "reference tracking: access after release", + .insns = { + BPF_SK_LOOKUP, + BPF_MOV64_REG(BPF_REG_1, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, 0), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .errstr = "!read_ok", + .result = REJECT, + }, + { + "reference tracking: direct access for lookup", + .insns = { + /* Check that the packet is at least 64B long */ + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_1, + offsetof(struct __sk_buff, data)), + BPF_LDX_MEM(BPF_W, BPF_REG_3, BPF_REG_1, + offsetof(struct __sk_buff, data_end)), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_2), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, 64), + BPF_JMP_REG(BPF_JGT, BPF_REG_0, BPF_REG_3, 9), + /* sk = sk_lookup_tcp(ctx, skb->data, ...) */ + BPF_MOV64_IMM(BPF_REG_3, sizeof(struct bpf_sock_tuple)), + BPF_MOV64_IMM(BPF_REG_4, 0), + BPF_MOV64_IMM(BPF_REG_5, 0), + BPF_EMIT_CALL(BPF_FUNC_sk_lookup_tcp), + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 3), + BPF_LDX_MEM(BPF_W, BPF_REG_2, BPF_REG_0, 4), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_6), + BPF_EMIT_CALL(BPF_FUNC_sk_release), + BPF_EXIT_INSN(), + }, + .prog_type = BPF_PROG_TYPE_SCHED_CLS, + .result = ACCEPT, + }, }; static int probe_filter_length(const struct bpf_insn *fp)