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 606C3C433F5 for ; Wed, 6 Apr 2022 10:47:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233423AbiDFKtp (ORCPT ); Wed, 6 Apr 2022 06:49:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40260 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359118AbiDFKsX (ORCPT ); Wed, 6 Apr 2022 06:48:23 -0400 Received: from mail-pf1-x436.google.com (mail-pf1-x436.google.com [IPv6:2607:f8b0:4864:20::436]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 96755505E65 for ; Wed, 6 Apr 2022 00:12:18 -0700 (PDT) Received: by mail-pf1-x436.google.com with SMTP id bo5so1689308pfb.4 for ; Wed, 06 Apr 2022 00:12:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=A1ZmQ0LEmR3OOKCT6LbGpsJN17JrWfuCp3spOBn+7ys=; b=imWh4RFwVhwV48pgB5H2Rk9lgcGiJab6/fGqHvtiXUfwCecaFw9d3PBd2m0v8TgPjF 3MUi9AyWZq8oup4KtE202CWPc2OV4UgUv32ciSiHLRXPi+HsjYpMPo2n9gvKc/nX44hd UeqfcT6zSLJiuW+85EyQ6bvae5Q1jEaCn+KME= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=A1ZmQ0LEmR3OOKCT6LbGpsJN17JrWfuCp3spOBn+7ys=; b=fVHcUqKDUN5fmH4ghlyjp3UspHX9/op/iTxN3555kG2Gdrlyk1VaYaaReMaHyhaSnx N2SQDEXl3F/WCjEcmtnEK+rqRboMxxbXnqlajifIvGkA3TlkpcR/IzLPGLc1cQi0ldve vbsbEgfACWhySWKM0Z540haiQsLx8xerPHV9E9MV7R5Hhdn8I/yasEirpar6pPufXp8Q 7Puz/W9FMp1lufcL8sg5XbSMOECxumFlc6LU/wlmRykH0mm6pFsXZnx7uGrFZUvl3GIR sM/9NfD0Fk1177652qOLo9JlFNlqwxGBHTKFbikcbOH+lL/nKou6KEqxN11DnePXFc1U agSg== X-Gm-Message-State: AOAM5322SCcPQVc7savUOpNAHAwKk6gc1s8k1dN2k8SAdYUcxYBAPM5X vUfcV7yuP60Wgik/ArCAtklmniHRfiNvrQ== X-Google-Smtp-Source: ABdhPJwVlccxYEcB9HkcJAYauOW/XtRZfeWCrlBKg8E7IQob9Y2pKkVaemr+VLJQZqmkw5oKOWTliA== X-Received: by 2002:a05:6a00:1510:b0:4fa:f5fe:ffd5 with SMTP id q16-20020a056a00151000b004faf5feffd5mr7477279pfu.2.1649229137998; Wed, 06 Apr 2022 00:12:17 -0700 (PDT) Received: from localhost ([2401:fa00:8f:203:f953:ca90:a854:80ca]) by smtp.gmail.com with UTF8SMTPSA id g6-20020a056a000b8600b004faa49add69sm17893931pfj.107.2022.04.06.00.12.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 06 Apr 2022 00:12:17 -0700 (PDT) From: David Stevens X-Google-Original-From: David Stevens To: linux-pci@vger.kernel.org Cc: Bjorn Helgaas , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, David Stevens Subject: [RFC] PCI: sysfs: add bypass for config read admin check Date: Wed, 6 Apr 2022 16:11:31 +0900 Message-Id: <20220406071131.2930035-1-stevensd@google.com> X-Mailer: git-send-email 2.35.1.1094.g7c7d902a7c-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: David Stevens Add a moduleparam that can be set to bypass the check that limits users without CAP_SYS_ADMIN to only being able to read the first 64 bytes of the config space. This allows systems without problematic hardware to be configured to allow users without CAP_SYS_ADMIN to read PCI capabilities. Signed-off-by: David Stevens --- drivers/pci/pci-sysfs.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 602f0fb0b007..162423b3c052 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -28,10 +28,17 @@ #include #include #include +#include #include "pci.h" static int sysfs_initialized; /* = 0 */ +static bool allow_unsafe_config_reads; +module_param_named(allow_unsafe_config_reads, + allow_unsafe_config_reads, bool, 0644); +MODULE_PARM_DESC(allow_unsafe_config_reads, + "Enable full read access to config space without CAP_SYS_ADMIN."); + /* show configuration fields */ #define pci_config_attr(field, format_string) \ static ssize_t \ @@ -696,7 +703,8 @@ static ssize_t pci_read_config(struct file *filp, struct kobject *kobj, u8 *data = (u8 *) buf; /* Several chips lock up trying to read undefined config space */ - if (file_ns_capable(filp, &init_user_ns, CAP_SYS_ADMIN)) + if (allow_unsafe_config_reads || + file_ns_capable(filp, &init_user_ns, CAP_SYS_ADMIN)) size = dev->cfg_size; else if (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) size = 128; -- 2.35.1.1094.g7c7d902a7c-goog