From patchwork Fri Sep 4 11:23:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenz Bauer X-Patchwork-Id: 1357369 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=KnR2n4I0; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Bjb791KySz9sVM for ; Fri, 4 Sep 2020 21:29:41 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730044AbgIDL3j (ORCPT ); Fri, 4 Sep 2020 07:29:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730202AbgIDL0C (ORCPT ); Fri, 4 Sep 2020 07:26:02 -0400 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49054C0619C5 for ; Fri, 4 Sep 2020 04:24:22 -0700 (PDT) Received: by mail-wm1-x341.google.com with SMTP id s13so5718509wmh.4 for ; Fri, 04 Sep 2020 04:24:22 -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=55VGPuW8E1FFOJXYmazHOmmDWGJoPY4/0mNdm6zV/ZQ=; b=KnR2n4I0ZBE+/DEJ0TXHS9GIUnsm5gt1Lwpi1BBrWqg9RRQFefOGWueZJScxPHyhpe M/EZuVKnY785pXOfSlHppv3hcy0BxqOi9zaiM/vjHsJ6oLgEhLxfo/08l5P5THlrZfYU V4KKV0GlYkQxYGcKUfB0C3UD9A2S+jlYBoOUg= 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=55VGPuW8E1FFOJXYmazHOmmDWGJoPY4/0mNdm6zV/ZQ=; b=mQi5Sx2JCggPNMkoAfDOsh1wvzeNyN+HDggyUXgp0pGFpFTusailszK40bfgH1/iwh dJZLL6mmiGYGzDzUCUYyNbhv6bgyXvriqgKOkZ4ypn7E5WGHKS6Ys1jxufsYawRRti67 Iy26cnm3Edp38V3/33qmE7SIdOhpM3yKUaI8/v2YCxLXO26uPmIbuvPcEZ3WgAvCKl3L ZX7fH1jHoltHb5ul89FDEIaXzzW5ZpzbYwlnnzbl0p548hiBeaYoTDAUz+xXvr0w5AMh P+FJy5CYU10AZMgMSNVE4/ycmqAxAwAPLnvNPS0banWmAhDxjYTxLrvk9lX1fKQIKUwn Zi2Q== X-Gm-Message-State: AOAM5300Plykx0jPo8IrLulADi1L1cW8/5GpWHfb4qZEYg+zpB1L8jns 0t17QKhAAZ+CgU+mjSNdnhiTGudHR1LpFg== X-Google-Smtp-Source: ABdhPJzUS5ogQZmPtTU0+pOrqs/97OQzVwfd6J2wgxTDd9aLgq4Rf9gi12qss+/erQ76heEc3EmRXg== X-Received: by 2002:a7b:c775:: with SMTP id x21mr6889037wmk.47.1599218660995; Fri, 04 Sep 2020 04:24:20 -0700 (PDT) Received: from antares.lan (111.253.187.81.in-addr.arpa. [81.187.253.111]) by smtp.gmail.com with ESMTPSA id v2sm9104408wrm.16.2020.09.04.04.24.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Sep 2020 04:24:20 -0700 (PDT) From: Lorenz Bauer To: ast@kernel.org, yhs@fb.com, daniel@iogearbox.net, kafai@fb.com Cc: bpf@vger.kernel.org, kernel-team@cloudflare.com, Lorenz Bauer Subject: [PATCH bpf-next 07/11] bpf: always check access to PTR_TO_CTX regardless of arg_type Date: Fri, 4 Sep 2020 12:23:57 +0100 Message-Id: <20200904112401.667645-8-lmb@cloudflare.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200904112401.667645-1-lmb@cloudflare.com> References: <20200904112401.667645-1-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. Signed-off-by: Lorenz Bauer --- kernel/bpf/verifier.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index c7df4ccad8e2..ba710a702cae 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3979,9 +3979,6 @@ 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; @@ -4081,6 +4078,12 @@ static int check_func_arg(struct bpf_verifier_env *env, u32 arg, meta->ref_obj_id = reg->ref_obj_id; } + if (type == PTR_TO_CTX) { + err = check_ctx_reg(env, reg, regno); + if (err < 0) + return err; + } + if (arg_type == ARG_CONST_MAP_PTR) { /* bpf_map_xxx(map_ptr) call: remember that map_ptr */ meta->map_ptr = reg->map_ptr;