From patchwork Thu Mar 8 01:34:38 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 7156 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 459C023EA9 for ; Thu, 8 Mar 2012 01:34:57 +0000 (UTC) Received: from mail-iy0-f180.google.com (mail-iy0-f180.google.com [209.85.210.180]) by fiordland.canonical.com (Postfix) with ESMTP id 08669A18466 for ; Thu, 8 Mar 2012 01:34:56 +0000 (UTC) Received: by mail-iy0-f180.google.com with SMTP id e36so12685171iag.11 for ; Wed, 07 Mar 2012 17:34:56 -0800 (PST) Received: by 10.50.197.135 with SMTP id iu7mr3577702igc.50.1331170496818; Wed, 07 Mar 2012 17:34:56 -0800 (PST) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.231.53.18 with SMTP id k18csp160ibg; Wed, 7 Mar 2012 17:34:54 -0800 (PST) Received: by 10.52.173.104 with SMTP id bj8mr6891603vdc.83.1331170493338; Wed, 07 Mar 2012 17:34:53 -0800 (PST) Received: from e6.ny.us.ibm.com (e6.ny.us.ibm.com. [32.97.182.146]) by mx.google.com with ESMTPS id ip8si124920vdb.19.2012.03.07.17.34.53 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 07 Mar 2012 17:34:53 -0800 (PST) Received-SPF: pass (google.com: domain of jstultz@us.ibm.com designates 32.97.182.146 as permitted sender) client-ip=32.97.182.146; Authentication-Results: mx.google.com; spf=pass (google.com: domain of jstultz@us.ibm.com designates 32.97.182.146 as permitted sender) smtp.mail=jstultz@us.ibm.com Received: from /spool/local by e6.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 7 Mar 2012 20:34:52 -0500 Received: from d01dlp01.pok.ibm.com (9.56.224.56) by e6.ny.us.ibm.com (192.168.1.106) with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted; Wed, 7 Mar 2012 20:34:50 -0500 Received: from d01relay01.pok.ibm.com (d01relay01.pok.ibm.com [9.56.227.233]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 43B6738C803A; Wed, 7 Mar 2012 20:34:49 -0500 (EST) Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay01.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q281Yn81208628; Wed, 7 Mar 2012 20:34:49 -0500 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q281YmWI013966; Wed, 7 Mar 2012 22:34:49 -0300 Received: from kernel.beaverton.ibm.com (kernel.beaverton.ibm.com [9.47.67.96]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id q281YmHt013955; Wed, 7 Mar 2012 22:34:48 -0300 Received: by kernel.beaverton.ibm.com (Postfix, from userid 1056) id CF2DAC0420; Wed, 7 Mar 2012 17:34:46 -0800 (PST) From: John Stultz To: lkml Cc: Nick Kralevich , Greg KH , Android Kernel Team , John Stultz Subject: [PATCH 11/11] android: ram_console: honor dmesg_restrict Date: Wed, 7 Mar 2012 17:34:38 -0800 Message-Id: <1331170478-30538-12-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.3.2.146.gca209 In-Reply-To: <1331170478-30538-1-git-send-email-john.stultz@linaro.org> References: <1331170478-30538-1-git-send-email-john.stultz@linaro.org> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12030801-1976-0000-0000-00000B456AE5 X-Gm-Message-State: ALoCoQktfiQvj35JcJ+Jn8EmZKwPUEtMQQgrjsQrbYYz8PtafYknmsLVf1RGM9I/1Yq3Px114Dku From: Nick Kralevich The Linux kernel has a setting called dmesg_restrict. When true, only processes with CAP_SYSLOG can view the kernel dmesg logs. This helps prevent leaking of kernel information into user space. On Android, it's possible to bypass these restrictions by viewing /proc/last_kmsg. This change makes /proc/last_kmsg require the same permissions as dmesg. CC: Greg KH CC: Android Kernel Team Signed-off-by: Nick Kralevich Signed-off-by: John Stultz --- drivers/staging/android/ram_console.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/drivers/staging/android/ram_console.c b/drivers/staging/android/ram_console.c index d956b84..b242be2 100644 --- a/drivers/staging/android/ram_console.c +++ b/drivers/staging/android/ram_console.c @@ -99,6 +99,9 @@ static ssize_t ram_console_read_old(struct file *file, char __user *buf, char *str; int ret; + if (dmesg_restrict && !capable(CAP_SYSLOG)) + return -EPERM; + /* Main last_kmsg log */ if (pos < old_log_size) { count = min(len, (size_t)(old_log_size - pos));