From patchwork Fri May 12 19:43:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicholas Bishop X-Patchwork-Id: 681435 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 20708C77B7F for ; Fri, 12 May 2023 19:43:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238892AbjELTnP (ORCPT ); Fri, 12 May 2023 15:43:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238467AbjELTnO (ORCPT ); Fri, 12 May 2023 15:43:14 -0400 Received: from mail-vk1-xa49.google.com (mail-vk1-xa49.google.com [IPv6:2607:f8b0:4864:20::a49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58B75D074 for ; Fri, 12 May 2023 12:43:05 -0700 (PDT) Received: by mail-vk1-xa49.google.com with SMTP id 71dfb90a1353d-43fa9a00625so2208247e0c.2 for ; Fri, 12 May 2023 12:43:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683920584; x=1686512584; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=YLH/bA+yhFKgRgD/PfBdmu3fiVXAEJ3yCxJiyJbAdz8=; b=HRpWvZHQhiD+sYYJ1K5rzdIiHd2Yle38oUBMZ4BHlDYoUtRsa69jA3USb7nZfgfV0S ydMxAtyjb7m5VN0Me0ArhPOxPrj0OAdH+fKA2gzeqKYjNy3drxmeSCOkRcU9iuM8eowx zS6DnMSxPBzwV/p8TnfWcrKVEKgst0vYDIi7OpdhVXkTs7dnPcGR6LYQiCDCObrVOXHC gpMAPBDWA0iMTdQxU4WDcIhbqmNSKwCTH0+5e5MJSK+4ek5ubEclbuzPb3Gc0RLJGRs5 cRPG9cbKwMtOzyM5lV3j6NxYp08suB9JAAe69YHwa5E3NQni/K63Z/1h+9kn3HrsVLz4 aYtg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683920584; x=1686512584; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=YLH/bA+yhFKgRgD/PfBdmu3fiVXAEJ3yCxJiyJbAdz8=; b=G/65INXbsI+jzzjh5SvTjFikHETyCcVTbOk0MafkJcZFW6caZM3fiDa0nBxac0vH0D w8G/q4lQcLxbg63ECqVohNx62Fn5kaVECwDUs1ExMoELTrVcLUD2maRBscYf9P8AkRO2 UueGlMnYWLy1PbeRFZGJjZJTFfXNn4o0xjCyb5y0y5hslvFP5n9Onm/BOkdXPXfTPWCJ Q0mimYkSLPzt0nCCpa90bf8KGf1Hv0kq4v7J+H+QREsZBRNu2qFtc1AwZZfnK/1FRdG/ ze06J5TNplGR0nEYoWyytav2ynRCB4OaY/cgUQIbbDycPMVnOIReNIAu6wtQpNAhstiE wjyw== X-Gm-Message-State: AC+VfDy5qPQG+w3rq9Cct42oMO6yI4agvE5L19Ant/jyWf1uWgYKZ3aB dXrYKEcvU/l+61mtZD3AW27HY7ThliU9V5ZlD1xcFg== X-Google-Smtp-Source: ACHHUZ7Fp1jAB8Erug5aU4TplWPM/WGhwnxeGeFU3SLJ9CkdxMdKQyNgUktT6VvojByoMdCi8ac8BldwJdkfp/D91LWepA== X-Received: from admirable.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:2888]) (user=nicholasbishop job=sendgmr) by 2002:a1f:ac8d:0:b0:453:eb8:5fef with SMTP id v135-20020a1fac8d000000b004530eb85fefmr7913684vke.2.1683920584402; Fri, 12 May 2023 12:43:04 -0700 (PDT) Date: Fri, 12 May 2023 19:43:02 +0000 Mime-Version: 1.0 X-Mailer: git-send-email 2.40.1.606.ga4b1b128d6-goog Message-ID: <20230512194302.1662230-1-nicholasbishop@google.com> Subject: [PATCH] efi/esrt: Allow ESRT access without CAP_SYS_ADMIN From: Nicholas Bishop To: Ard Biesheuvel , linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Peter Jones , Nicholas Bishop Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Access to the files in /sys/firmware/efi/esrt has been restricted to CAP_SYS_ADMIN since support for ESRT was added, but this seems overly restrictive given that the files are read-only and just provide information about UEFI firmware updates. Remove the CAP_SYS_ADMIN restriction so that a non-root process can read the files, provided a suitably-privileged process changes the file ownership first. The files are still read-only and still owned by root by default. Signed-off-by: Nicholas Bishop --- drivers/firmware/efi/esrt.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/firmware/efi/esrt.c b/drivers/firmware/efi/esrt.c index d5915272141f..aab96ab64a1a 100644 --- a/drivers/firmware/efi/esrt.c +++ b/drivers/firmware/efi/esrt.c @@ -95,10 +95,6 @@ static ssize_t esre_attr_show(struct kobject *kobj, struct esre_entry *entry = to_entry(kobj); struct esre_attribute *attr = to_attr(_attr); - /* Don't tell normal users what firmware versions we've got... */ - if (!capable(CAP_SYS_ADMIN)) - return -EACCES; - return attr->show(entry, buf); }