From patchwork Wed Sep 9 17:11:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenz Bauer X-Patchwork-Id: 1360832 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=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=reject dis=none) header.from=cloudflare.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; secure) header.d=cloudflare.com header.i=@cloudflare.com header.a=rsa-sha256 header.s=google header.b=psXWU7wd; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BmpVm1GbDz9sTd for ; Thu, 10 Sep 2020 03:12:48 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731237AbgIIRMO (ORCPT ); Wed, 9 Sep 2020 13:12:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731221AbgIIRMM (ORCPT ); Wed, 9 Sep 2020 13:12:12 -0400 Received: from mail-wm1-x343.google.com (mail-wm1-x343.google.com [IPv6:2a00:1450:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 43F28C061757 for ; Wed, 9 Sep 2020 10:12:12 -0700 (PDT) Received: by mail-wm1-x343.google.com with SMTP id w2so3037403wmi.1 for ; Wed, 09 Sep 2020 10:12:12 -0700 (PDT) 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=dnZ331gfN/AeE7WivZ3vPwmqFG0W8bqGKgBfqzj0+f0=; b=psXWU7wdb09Z/i/Nfal00GgYW+MQc+h5BRgakVyd/6TXD0sTbcS/AYXUxNCMX/+x2b zV7Vg3J0divMPOwmj9/8P4fkyu9Eq11+qqJ6vxq2ceDLqkKKrAMD8/eb+0n6Fh3YfB/T tXO2VnFkK4KAh4yiNPxBk0mxGJDBrHyoqU+U8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=dnZ331gfN/AeE7WivZ3vPwmqFG0W8bqGKgBfqzj0+f0=; b=osBm5YvN2hfxe7OC+3rE26/LWkazFz5yoU2Ew2Wt8PVGOvMADCk4t9dxInfaku/rHS +m+xqWfjwxvQ/lXudAj5UQqNHNWNJ59MJ/jgRjbea7w2HTu8EKqPbn6MQrVx6yYX27OX hbI730LH7ynw1ZXrwvaXXZ3SuCV+eywicnIZ7FAAAl/BTItIOoWSGU70vcsZhth++ddC cmirpFXB1filIIiXkADRX6af/DfyGrHlnxRLn4dLAXmhroMcQr7Ne272+shb8lKE7jCd GyXR/6BxkM05ylm59nG8/lHXjHoA2ycumHldzNq6kaBZkVTYd2n+QYOSosYYmMZx1jC7 v6eA== X-Gm-Message-State: AOAM5316dlLraiB32ZVNlf90Ejl+U9snrwe1B+rr1XuX9hv5BkLMsnXq Ok8vaXkElFevCQ1K6K/ovFriOQ== X-Google-Smtp-Source: ABdhPJzg8eSZKKDXD54EvswQnL0ZKe0cKv2sPGMxX2xYXEFaY4a/xBtVHUV9jE/b7kKW0hE7tbVxLw== X-Received: by 2002:a7b:cd05:: with SMTP id f5mr4457218wmj.116.1599671530982; Wed, 09 Sep 2020 10:12:10 -0700 (PDT) Received: from antares.lan (1.3.0.0.8.d.4.4.b.b.8.a.1.4.5.e.f.f.6.2.a.5.a.7.0.b.8.0.1.0.0.2.ip6.arpa. [2001:8b0:7a5a:26ff:e541:a8bb:44d8:31]) by smtp.gmail.com with ESMTPSA id g131sm3746743wmf.25.2020.09.09.10.12.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 09 Sep 2020 10:12:10 -0700 (PDT) From: Lorenz Bauer To: ast@kernel.org, yhs@fb.com, daniel@iogearbox.net, kafai@fb.com, andriin@fb.com Cc: bpf@vger.kernel.org, kernel-team@cloudflare.com, Lorenz Bauer Subject: [PATCH bpf-next v2 07/11] bpf: make context access check generic Date: Wed, 9 Sep 2020 18:11:51 +0100 Message-Id: <20200909171155.256601-8-lmb@cloudflare.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200909171155.256601-1-lmb@cloudflare.com> References: <20200909171155.256601-1-lmb@cloudflare.com> MIME-Version: 1.0 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Always check context access if the register we're operating on is PTR_TO_CTX, rather than relying on ARG_PTR_TO_CTX. This allows simplifying the arg_type checking section of the function. Signed-off-by: Lorenz Bauer Acked-by: Martin KaFai Lau --- kernel/bpf/verifier.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 43df3bae93aa..41643e179e14 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3974,9 +3974,6 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, arg_type == ARG_PTR_TO_CTX_OR_NULL)) { if (type != expected_type) goto err_type; - err = check_ctx_reg(env, reg, regno); - if (err < 0) - return err; } } else if (arg_type == ARG_PTR_TO_SOCK_COMMON) { expected_type = PTR_TO_SOCK_COMMON; @@ -4060,6 +4057,10 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, regno); return -EACCES; } + } else if (type == PTR_TO_CTX) { + err = check_ctx_reg(env, reg, regno); + if (err < 0) + return err; } if (reg->ref_obj_id) {