From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755905Ab2DDBvj (ORCPT ); Tue, 3 Apr 2012 21:51:39 -0400 Received: from out01.mta.xmission.com ([166.70.13.231]:38633 "EHLO out01.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755107Ab2DDBve (ORCPT ); Tue, 3 Apr 2012 21:51:34 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: Andrew Morton Cc: "Serge E. Hallyn" , Philipp Reisner , Patrick McHardy , Andrew Morgan , Vasiliy Kulikov , David Howells , Neil Brown , Michal Januszewski , , , linux-fbdev@vger.kernel.org, linux-raid@vger.kernel.org Date: Tue, 03 Apr 2012 18:55:13 -0700 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-XM-SPF: eid=;;;mid=;;;hst=in01.mta.xmission.com;;;ip=98.207.153.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX18ei/iV+yuroe54VcF7peFbZLtBCsR/Zo4= X-SA-Exim-Connect-IP: 98.207.153.68 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * 0.1 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -0.5 BAYES_05 BODY: Bayes spam probability is 1 to 5% * [score: 0.0127] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa06 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.1 XMSolicitRefs_0 Weightloss drug * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay X-Spam-DCC: XMission; sa06 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ;Andrew Morton X-Spam-Relay-Country: ** Subject: [PATCH] userns: Replace netlink uses of cap_raised with capable. X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Fri, 06 Aug 2010 16:31:04 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In 2009 Philip Reiser notied that a few users of netlink connector interface needed a capability check and added the idiom cap_raised(nsp->eff_cap, CAP_SYS_ADMIN) to a few of them, on the premise that netlink was asynchronous. In 2011 Patrick McHardy noticed we were being silly because netlink is synchronous and removed eff_cap from the netlink_skb_params and changed the idiom to cap_raised(current_cap(), CAP_SYS_ADMIN). Looking at those spots with a fresh eye we should be calling capable(CAP_SYS_ADMIN). The only reason I can see for not calling capable is that it once appeared we were not in the same task as the caller which would have made calling capable() impossible. In the initial user_namespace the only difference between between cap_raised(current_cap(), CAP_SYS_ADMIN) and capable(CAP_SYS_ADMIN) are a few sanity checks and the fact that capable(CAP_SYS_ADMIN) sets PF_SUPERPRIV if we use the capability. Since we are going to be using root privilege setting PF_SUPERPRIV seems the right thing to do. The motivation for this that patch is that in a child user namespace cap_raised(current_cap(),...) tests your capabilities with respect to that child user namespace not capabilities in the initial user namespace and thus will allow processes that should be unprivielged to use the kernel services that are only protected with cap_raised(current_cap(),..). To fix possible user_namespace issues and to just clean up the code replace cap_raised(current_cap(), CAP_SYS_ADMIN) with capable(CAP_SYS_ADMIN). Cc: Patrick McHardy Cc: Philipp Reisner Cc: Serge E. Hallyn Cc: Andrew Morgan Cc: Vasiliy Kulikov Cc: David Howells Signed-off-by: Eric W. Biederman --- drivers/block/drbd/drbd_nl.c | 2 +- drivers/md/dm-log-userspace-transfer.c | 2 +- drivers/video/uvesafb.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c index abfaaca..946166e 100644 --- a/drivers/block/drbd/drbd_nl.c +++ b/drivers/block/drbd/drbd_nl.c @@ -2297,7 +2297,7 @@ static void drbd_connector_callback(struct cn_msg *req, struct netlink_skb_parms return; } - if (!cap_raised(current_cap(), CAP_SYS_ADMIN)) { + if (!capable(CAP_SYS_ADMIN)) { retcode = ERR_PERM; goto fail; } diff --git a/drivers/md/dm-log-userspace-transfer.c b/drivers/md/dm-log-userspace-transfer.c index 1f23e04..08d9a20 100644 --- a/drivers/md/dm-log-userspace-transfer.c +++ b/drivers/md/dm-log-userspace-transfer.c @@ -134,7 +134,7 @@ static void cn_ulog_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp) { struct dm_ulog_request *tfr = (struct dm_ulog_request *)(msg + 1); - if (!cap_raised(current_cap(), CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN)) return; spin_lock(&receiving_list_lock); diff --git a/drivers/video/uvesafb.c b/drivers/video/uvesafb.c index 260cca7..9f7d27a 100644 --- a/drivers/video/uvesafb.c +++ b/drivers/video/uvesafb.c @@ -73,7 +73,7 @@ static void uvesafb_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *ns struct uvesafb_task *utask; struct uvesafb_ktask *task; - if (!cap_raised(current_cap(), CAP_SYS_ADMIN)) + if (!capable(CAP_SYS_ADMIN)) return; if (msg->seq >= UVESAFB_TASKS_MAX) -- 1.7.2.5