From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Lutomirski , "Eric W. Biederman" Subject: [ 101/117] proc: Restrict mounting the proc filesystem Date: Tue, 24 Sep 2013 17:19:27 -0700 Message-Id: <20130925001751.955136287@linuxfoundation.org> In-Reply-To: <20130925001740.833541979@linuxfoundation.org> References: <20130925001740.833541979@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Eric W. Biederman" commit aee1c13dd0f6c2fc56e0e492b349ee8ac655880f upstream. Don't allow mounting the proc filesystem unless the caller has CAP_SYS_ADMIN rights over the pid namespace. The principle here is if you create or have capabilities over it you can mount it, otherwise you get to live with what other people have mounted. Andy pointed out that this is needed to prevent users in a user namespace from remounting proc and specifying different hidepid and gid options on already existing proc mounts. Reported-by: Andy Lutomirski Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman --- fs/proc/root.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -110,7 +110,8 @@ static struct dentry *proc_mount(struct ns = task_active_pid_ns(current); options = data; - if (!current_user_ns()->may_mount_proc) + if (!current_user_ns()->may_mount_proc || + !ns_capable(ns->user_ns, CAP_SYS_ADMIN)) return ERR_PTR(-EPERM); }