From patchwork Tue Mar 28 08:56:41 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Reshetova, Elena" X-Patchwork-Id: 9648543 X-Patchwork-Delegate: kvalo@adurom.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4F03960351 for ; Tue, 28 Mar 2017 09:06:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 41BBA28306 for ; Tue, 28 Mar 2017 09:06:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 30FAA27C0B; Tue, 28 Mar 2017 09:06:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DBFDD27C0B for ; Tue, 28 Mar 2017 09:06:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755386AbdC1JFX (ORCPT ); Tue, 28 Mar 2017 05:05:23 -0400 Received: from mga09.intel.com ([134.134.136.24]:30539 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754838AbdC1I6c (ORCPT ); Tue, 28 Mar 2017 04:58:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=intel.com; i=@intel.com; q=dns/txt; s=intel; t=1490691511; x=1522227511; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=wGWVxvxD3ePVK04snav1PQ56XJFktTEUNVUWjFAL9wI=; b=JE/sRApApLB6tM1UHaaFMR6F7dR7qYlFljC1e8ZcnyYFjYZsgmGzS00S zJzU7Ws9YMrWxNoAk+vRXa9euc0L8g==; Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Mar 2017 01:58:30 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.36,236,1486454400"; d="scan'208";a="81798271" Received: from unknown (HELO elena-ThinkPad-X230.ger.corp.intel.com) ([10.249.44.56]) by fmsmga006.fm.intel.com with ESMTP; 28 Mar 2017 01:58:23 -0700 From: Elena Reshetova To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rdma@vger.kernel.org, linux-hams@vger.kernel.org, linux-ppp@vger.kernel.org, linux-wireless@vger.kernel.org, ganeshgr@chelsio.com, nbd@openwrt.org, blogic@openwrt.org, matthias.bgg@gmail.com, yishaih@mellanox.com, saeedm@mellanox.com, matanb@mellanox.com, leonro@mellanox.com, ajk@comnets.uni-bremen.de, paulus@samba.org, j@w1.fi, kvalo@codeaurora.org, peterz@infradead.org, keescook@chromium.org, gregkh@linuxfoundation.org, Elena Reshetova , Hans Liljestrand , David Windsor Subject: [PATCH 14/16] drivers, net, ppp: convert syncppp.refcnt from atomic_t to refcount_t Date: Tue, 28 Mar 2017 11:56:41 +0300 Message-Id: <1490691403-4016-15-git-send-email-elena.reshetova@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1490691403-4016-1-git-send-email-elena.reshetova@intel.com> References: <1490691403-4016-1-git-send-email-elena.reshetova@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova Signed-off-by: Hans Liljestrand Signed-off-by: Kees Cook Signed-off-by: David Windsor --- drivers/net/ppp/ppp_synctty.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/net/ppp/ppp_synctty.c b/drivers/net/ppp/ppp_synctty.c index 9ae5398..4a643f8 100644 --- a/drivers/net/ppp/ppp_synctty.c +++ b/drivers/net/ppp/ppp_synctty.c @@ -46,6 +46,7 @@ #include #include #include +#include #include #include @@ -72,7 +73,7 @@ struct syncppp { struct tasklet_struct tsk; - atomic_t refcnt; + refcount_t refcnt; struct completion dead_cmp; struct ppp_channel chan; /* interface to generic ppp layer */ }; @@ -141,14 +142,14 @@ static struct syncppp *sp_get(struct tty_struct *tty) read_lock(&disc_data_lock); ap = tty->disc_data; if (ap != NULL) - atomic_inc(&ap->refcnt); + refcount_inc(&ap->refcnt); read_unlock(&disc_data_lock); return ap; } static void sp_put(struct syncppp *ap) { - if (atomic_dec_and_test(&ap->refcnt)) + if (refcount_dec_and_test(&ap->refcnt)) complete(&ap->dead_cmp); } @@ -182,7 +183,7 @@ ppp_sync_open(struct tty_struct *tty) skb_queue_head_init(&ap->rqueue); tasklet_init(&ap->tsk, ppp_sync_process, (unsigned long) ap); - atomic_set(&ap->refcnt, 1); + refcount_set(&ap->refcnt, 1); init_completion(&ap->dead_cmp); ap->chan.private = ap; @@ -232,7 +233,7 @@ ppp_sync_close(struct tty_struct *tty) * our channel ops (i.e. ppp_sync_send/ioctl) are in progress * by the time it returns. */ - if (!atomic_dec_and_test(&ap->refcnt)) + if (!refcount_dec_and_test(&ap->refcnt)) wait_for_completion(&ap->dead_cmp); tasklet_kill(&ap->tsk);