From patchwork Tue Nov 27 07:54:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pan Bian X-Patchwork-Id: 10699817 X-Patchwork-Delegate: sameo@linux.intel.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 896A713BF for ; Tue, 27 Nov 2018 07:55:24 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7E4A72AA7C for ; Tue, 27 Nov 2018 07:55:24 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 719C12AACB; Tue, 27 Nov 2018 07:55:24 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham 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 4357B2AA7C for ; Tue, 27 Nov 2018 07:55:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729276AbeK0SwR (ORCPT ); Tue, 27 Nov 2018 13:52:17 -0500 Received: from m12-11.163.com ([220.181.12.11]:51536 "EHLO m12-11.163.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728977AbeK0SwQ (ORCPT ); Tue, 27 Nov 2018 13:52:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id; bh=i2bcApeV8atCnz4/Q7 5l4r8++FCD2b8hoWXfmw7d/fg=; b=X4vl2QUMuSk7R134sT6PcuVYTTYghdSNI2 Fqj7PHHEX3CIA32bRMRIke2pOStDAr8xh1pSD8wr8MyrXv7+v5z2yEL2aH7ji00M DGZLqwkksY4XxjJN6z4pH7M1QM1PGDkFXELSOLq8b13KWmDgwxaQE7HSQnDnaBp5 JlhLe+WnU= Received: from bp.localdomain (unknown [106.120.213.96]) by smtp7 (Coremail) with SMTP id C8CowAC3GPw8+PxboYqRCA--.739S3; Tue, 27 Nov 2018 15:54:49 +0800 (CST) From: Pan Bian To: Samuel Ortiz , "David S. Miller" Cc: linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Pan Bian Subject: [PATCH] NFC: netlink: remove unexpected nfc_put_device Date: Tue, 27 Nov 2018 15:54:35 +0800 Message-Id: <1543305275-23051-1-git-send-email-bianpan2016@163.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: C8CowAC3GPw8+PxboYqRCA--.739S3 X-Coremail-Antispam: 1Uf129KBjvdXoW7XryfJw1rJrW5JrWUKr17Wrg_yoWDArgEyw 1rtr48Wrs5X3s3JF42kr4UAF92kF42gF4xG3WxKr4rAa45Xay5ZFWkAw4fAr17uw43CFW7 X3WkKFWkJry7XjkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU0oUDJUUUUU== X-Originating-IP: [106.120.213.96] X-CM-SenderInfo: held01tdqsiiqw6rljoofrz/1tbiVAIMclUMGLObWgAAsb 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 The functions nfc_genl_llc_set_params and nfc_genl_llc_sdreq drops the reference to dev via nfc_put_device on the error branch that no local device is found. However, the error handling block reads dev's field and then put dev again. This may result in use-after-free bugs. The patch removes the unexpected call to nfc_put_device. Signed-off-by: Pan Bian --- net/nfc/netlink.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c index 376181c..e1f2057 100644 --- a/net/nfc/netlink.c +++ b/net/nfc/netlink.c @@ -1107,7 +1107,6 @@ static int nfc_genl_llc_set_params(struct sk_buff *skb, struct genl_info *info) local = nfc_llcp_find_local(dev); if (!local) { - nfc_put_device(dev); rc = -ENODEV; goto exit; } @@ -1167,7 +1166,6 @@ static int nfc_genl_llc_sdreq(struct sk_buff *skb, struct genl_info *info) local = nfc_llcp_find_local(dev); if (!local) { - nfc_put_device(dev); rc = -ENODEV; goto exit; }