From mboxrd@z Thu Jan 1 00:00:00 1970 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 C5A8CC433FE for ; Tue, 18 Oct 2022 14:00:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229998AbiJROAT (ORCPT ); Tue, 18 Oct 2022 10:00:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51776 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231298AbiJROAG (ORCPT ); Tue, 18 Oct 2022 10:00:06 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 780127C30B for ; Tue, 18 Oct 2022 07:00:05 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id s196so12085676pgs.3 for ; Tue, 18 Oct 2022 07:00:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=fPT/xLfKFwrrU4SwJxKlx5kwl9p+8LOa5HNWJZWwq8Y=; b=oe9RVtZAyBl7MVuan/eUuIBqvHxSc6t9XvxK2aNTv4YQ0Bxa19I9h9mcDg1IZHzQXi 6yVeMw0pmpoDp8gpE20OKMjJ6lL7a+VGcefi91D7AP8S7ipiK2FBXVFZhCWTxJpnd7R9 44+5utvdbcdcQoWxTcFfwRA+dHysyxvmkC1/Wb8xxlDQDjRToaodspQKv5K4oNTJ51xh 67imcKRp4mNwZVUwB2JBwpn/c+Ad9MM9L8eCoNGICi4M0tLtoplK7k4yN//KiW/+7l/E Mv24+Jjs+PeL0ndeedyhvARbqZMAI8/E9GAWLUxFjOAmIBdwCOLpZ1P+G9tuBPermqq+ OVRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=fPT/xLfKFwrrU4SwJxKlx5kwl9p+8LOa5HNWJZWwq8Y=; b=rlQgONBKhri0dcSu+vtvlqt8lLKi9c5qT3qMDLq+vo6Fzs70inNS5illGv/6PZ7EBf oAc9MgNZTr7eGvdwtG0vWFDe9QJwwm8+0a2mMxAbjlQjLYMUbPlhvK2o4BoSPvLf3zw7 BCoz95+nuwJAjWvwdISRbWJzgTQFLrpYiQBCzpKqg42p0GZ9DytaeC1sla8omE4sKy6R uL/NMZ/tNYn+AiajRfkbz57Q4QMkhJc2Ll0Q3zSULEN1Czv3U+raSFTpCRm78x5QG413 IW886iE8aBtFZcsPBKOYnvt055Xrn0C6P0CEvZPQmLuYpO23WI3RKPO9gvjgc+G0714m HFKg== X-Gm-Message-State: ACrzQf36ucVVBFr9x5urr+/kTnW3k+Sx5h/JciYg3u3HXaJYHTZkMNey e+NbT6z2aICKwR29nEn8l+niZ8Q2fUtKfg== X-Google-Smtp-Source: AMsMyM56e5asRNUc/4hEuXI8Yu/eXQ+57HxgB/CWxlxAID/aRFotrnl761wTa1wIBi/z6+2t6lVNDg== X-Received: by 2002:aa7:85d7:0:b0:562:6079:3481 with SMTP id z23-20020aa785d7000000b0056260793481mr3047782pfn.77.1666101604747; Tue, 18 Oct 2022 07:00:04 -0700 (PDT) Received: from localhost ([103.4.222.252]) by smtp.gmail.com with ESMTPSA id i2-20020aa796e2000000b00560e5da42d5sm9136600pfq.201.2022.10.18.07.00.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 18 Oct 2022 07:00:04 -0700 (PDT) From: Kumar Kartikeya Dwivedi To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Joanne Koong , David Vernet Subject: [PATCH bpf-next v1 11/13] selftests/bpf: Add dynptr var_off tests Date: Tue, 18 Oct 2022 19:29:18 +0530 Message-Id: <20221018135920.726360-12-memxor@gmail.com> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221018135920.726360-1-memxor@gmail.com> References: <20221018135920.726360-1-memxor@gmail.com> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2558; i=memxor@gmail.com; h=from:subject; bh=lWtxzrANAZxyKY18Vsxv4Bbip2ZoyfaVfH5dUk1VWJk=; b=owEBbQKS/ZANAwAIAUzgyIZIvxHKAcsmYgBjTrEi9zSGeX57gcGd1S6tZ6TcqBjRE2nBrQm2pnqw lmHI1JOJAjMEAAEIAB0WIQRLvip+Buz51YI8YRFM4MiGSL8RygUCY06xIgAKCRBM4MiGSL8Ryn3HD/ 0RkvB7V2Thg++DgspbVjkbOlQ4MAMt9aBkPHujK/6qXjEeg2Y8yTWJ0FolfW1xmI0R2kIwYHbERp32 uCO/AwYAL6B8ddBU0ueX0s4dptw7RZeq5oOi0inryrDhXQcXZ9pdJV5ab/UH4wIA1TyBRqMMJTzNGk k4htyRyAbSMFac2olvR1bp2OuOzDfEYvoIZUBv18E1CPice2q+Urx/4IxqUVv6mS4tKj6wz8OcEdSo xJOPxxCRvrDtvuy8cNjmh8z3ixk2Hkg0mQSWSP+cMZlmhXRMaZVDXi4RSejtfZwY97Fp1Km8e+O5jf UiYMYn5ZNpnofTkzrgY8VKo22ksgjIBnaOUWLmSJNSQbQgtSxy0U58MxEjx9mQIB8oLkixBvEShfBv pT5vVMYKUKMH9q2MzOeE/6LdA+QqcNKbjqvh+84is4gdQdjKApSIUpjfkZ6y7gbRWalUeyxKJVB3PE wyX+k7GXkM2CXk63ZYIooHxagrEJZEyTjGIxhjIePwKnC0XCFiaSMu5clA/PhtyxB0OQLUP2aKlK9/ MrdkSesN1jA3gTNy1B6F56T1c5ae9iXEaPcVl8B9L0/eeC78gpOtMczyqUG09GzIc3eEgTJQiMi2jm g/X6QCL2HMM1UmS4OB6IHEnD09rKXsl9phz/aboIp9CxhLZ9S1czoipdlXVg== X-Developer-Key: i=memxor@gmail.com; a=openpgp; fpr=4BBE2A7E06ECF9D5823C61114CE0C88648BF11CA Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Ensure that variable offset is handled correctly, and verifier takes both fixed and variable part into account. Also ensure that only constant var_off is allowed. Make sure that unprivileged BPF cannot use var_off for dynptr. Signed-off-by: Kumar Kartikeya Dwivedi --- tools/testing/selftests/bpf/verifier/dynptr.c | 38 ++++++++++++++++++- 1 file changed, 36 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/verifier/dynptr.c b/tools/testing/selftests/bpf/verifier/dynptr.c index 798f4f7e0c57..1aa7241e8a9e 100644 --- a/tools/testing/selftests/bpf/verifier/dynptr.c +++ b/tools/testing/selftests/bpf/verifier/dynptr.c @@ -1,5 +1,5 @@ { - "dynptr: rewrite dynptr slot", + "dynptr: rewrite dynptr slot (pruning)", .insns = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_LD_MAP_FD(BPF_REG_6, 0), @@ -26,7 +26,7 @@ .errstr = "arg 1 is an unacquired reference", }, { - "dynptr: type confusion", + "dynptr: type confusion (pruning)", .insns = { BPF_MOV64_IMM(BPF_REG_0, 0), BPF_LD_MAP_FD(BPF_REG_6, 0), @@ -88,3 +88,37 @@ .result = REJECT, .errstr = "arg 1 is an unacquired reference", }, +{ + "dynptr: rewrite dynptr slot (var_off)", + .insns = { + BPF_ST_MEM(BPF_W, BPF_REG_10, -4, 16), + BPF_LDX_MEM(BPF_W, BPF_REG_8, BPF_REG_10, -4), + BPF_JMP_IMM(BPF_JGE, BPF_REG_8, 0, 2), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + BPF_JMP_IMM(BPF_JLE, BPF_REG_8, 16, 2), + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + BPF_ALU64_IMM(BPF_AND, BPF_REG_8, 16), + BPF_LD_MAP_FD(BPF_REG_1, 0), + BPF_MOV64_IMM(BPF_REG_2, 8), + BPF_MOV64_IMM(BPF_REG_3, 0), + BPF_MOV64_REG(BPF_REG_4, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_4, -32), + BPF_ALU64_REG(BPF_ADD, BPF_REG_4, BPF_REG_8), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_reserve_dynptr), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -16, 0xeB9F), + BPF_MOV64_REG(BPF_REG_1, BPF_REG_10), + BPF_ALU64_IMM(BPF_ADD, BPF_REG_1, -32), + BPF_ALU64_REG(BPF_ADD, BPF_REG_1, BPF_REG_8), + BPF_MOV64_IMM(BPF_REG_2, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_discard_dynptr), + BPF_MOV64_REG(BPF_REG_0, BPF_REG_8), + BPF_EXIT_INSN(), + }, + .fixup_map_ringbuf = { 9 }, + .result_unpriv = REJECT, + .errstr_unpriv = "R4 variable stack access prohibited for !root, var_off=(0x0; 0x10) off=-32", + .result = REJECT, + .errstr = "dynptr has to be at the constant offset", +}, -- 2.38.0