From patchwork Wed May 22 19:42:50 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 245702 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9864F2C0096 for ; Thu, 23 May 2013 05:42:35 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756817Ab3EVTmS (ORCPT ); Wed, 22 May 2013 15:42:18 -0400 Received: from ip4-83-240-18-99.cust.nbox.cz ([83.240.18.99]:50539 "EHLO anemoi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752839Ab3EVTmR (ORCPT ); Wed, 22 May 2013 15:42:17 -0400 Received: from ku by anemoi with local (Exim 4.80.1) (envelope-from ) id 1UfEvy-0005oT-Rj; Wed, 22 May 2013 21:42:50 +0200 From: Jiri Slaby To: jirislaby@gmail.com Cc: linux-kernel@vger.kernel.org, Jeff Mahoney , Patrick Koppen , Jiri Slaby , Karsten Keil , netdev@vger.kernel.org, "David S. Miller" , Sergei Shtylyov Subject: [PATCH v2 -resend 1/6] mISDN: Add support for group membership check Date: Wed, 22 May 2013 21:42:50 +0200 Message-Id: <1369251770-22316-1-git-send-email-jslaby@suse.cz> X-Mailer: git-send-email 1.8.2.3 In-Reply-To: <519D16B4.7080905@cogentembedded.com> References: <519D16B4.7080905@cogentembedded.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jeff Mahoney This patch adds a module parameter to allow a group access to the mISDN devices. Otherwise, unpriviledged users on systems with ISDN hardware have the ability to dial out, potentially causing expensive bills. Based on a different implementation by Patrick Koppen . [v2] - convert to the new UID/GID API - fix whitespace issues (per Sergei) Acked-by: Jeff Mahoney Cc: Patrick Koppen Signed-off-by: Jiri Slaby Cc: Karsten Keil Cc: netdev@vger.kernel.org Cc: "David S. Miller" Cc: Sergei Shtylyov --- drivers/isdn/mISDN/core.c | 6 ++++++ drivers/isdn/mISDN/core.h | 1 + drivers/isdn/mISDN/socket.c | 9 +++++++++ 3 files changed, 16 insertions(+) diff --git a/drivers/isdn/mISDN/core.c b/drivers/isdn/mISDN/core.c index da30c5c..174aa3f 100644 --- a/drivers/isdn/mISDN/core.c +++ b/drivers/isdn/mISDN/core.c @@ -21,10 +21,14 @@ #include "core.h" static u_int debug; +static u_int gid; +kgid_t misdn_permitted_gid; MODULE_AUTHOR("Karsten Keil"); MODULE_LICENSE("GPL"); module_param(debug, uint, S_IRUGO | S_IWUSR); +module_param(gid, uint, 0); +MODULE_PARM_DESC(gid, "Unix group for accessing misdn socket (default 0)"); static u64 device_ids; #define MAX_DEVICE_ID 63 @@ -372,6 +376,8 @@ mISDNInit(void) { int err; + misdn_permitted_gid = make_kgid(current_user_ns(), gid); + printk(KERN_INFO "Modular ISDN core version %d.%d.%d\n", MISDN_MAJOR_VERSION, MISDN_MINOR_VERSION, MISDN_RELEASE); mISDN_init_clock(&debug); diff --git a/drivers/isdn/mISDN/core.h b/drivers/isdn/mISDN/core.h index 52695bb..5f509bf 100644 --- a/drivers/isdn/mISDN/core.h +++ b/drivers/isdn/mISDN/core.h @@ -17,6 +17,7 @@ extern struct mISDNdevice *get_mdevice(u_int); extern int get_mdevice_count(void); +extern kgid_t misdn_permitted_gid; /* stack status flag */ #define mISDN_STACK_ACTION_MASK 0x0000ffff diff --git a/drivers/isdn/mISDN/socket.c b/drivers/isdn/mISDN/socket.c index e47dcb9..8dcef36 100644 --- a/drivers/isdn/mISDN/socket.c +++ b/drivers/isdn/mISDN/socket.c @@ -612,6 +612,11 @@ data_sock_create(struct net *net, struct socket *sock, int protocol) { struct sock *sk; + if (!capable(CAP_SYS_ADMIN) && + !gid_eq(misdn_permitted_gid, current_gid()) && + !in_group_p(misdn_permitted_gid)) + return -EPERM; + if (sock->type != SOCK_DGRAM) return -ESOCKTNOSUPPORT; @@ -694,6 +699,10 @@ base_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) case IMSETDEVNAME: { struct mISDN_devrename dn; + if (!capable(CAP_SYS_ADMIN) && + !gid_eq(misdn_permitted_gid, current_gid()) && + !in_group_p(misdn_permitted_gid)) + return -EPERM; if (copy_from_user(&dn, (void __user *)arg, sizeof(dn))) { err = -EFAULT;