From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 956C3C433FE for ; Thu, 11 Nov 2021 14:14:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73F7F61179 for ; Thu, 11 Nov 2021 14:14:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233560AbhKKORC (ORCPT ); Thu, 11 Nov 2021 09:17:02 -0500 Received: from mail.zju.edu.cn ([61.164.42.155]:36374 "EHLO zju.edu.cn" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S231739AbhKKORB (ORCPT ); Thu, 11 Nov 2021 09:17:01 -0500 Received: from localhost.localdomain (unknown [222.205.2.245]) by mail-app3 (Coremail) with SMTP id cC_KCgB371IrJY1htn75Bw--.17565S4; Thu, 11 Nov 2021 22:14:03 +0800 (CST) From: Lin Ma To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, jirislaby@kernel.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, Lin Ma Subject: [PATCH v1] hamradio: remove needs_free_netdev to avoid UAF Date: Thu, 11 Nov 2021 22:14:02 +0800 Message-Id: <20211111141402.7551-1-linma@zju.edu.cn> X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: cC_KCgB371IrJY1htn75Bw--.17565S4 X-Coremail-Antispam: 1UD129KBjvJXoWrZFW3AFy5CrW3Ww13Ar18Xwb_yoW8Jry3pa yrCFWSyr18Gr1fCw1xAay8W3W5ua1Iv343ua4ag3s09rsxur1qkr18CFWj9r1jvFZ8A3W2 vF1jvryxA3Z5A3DanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvY1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AE w4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2 IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVWxJr0_GcWl84ACjcxK6I8E 87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_GcCE3s1le2I262IYc4CY6c 8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_JrI_ JrylYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwI xGrwACjI8F5VA0II8E6IAqYI8I648v4I1lc2xSY4AK67AK6ry5MxAIw28IcxkI7VAKI48J MxAIw28IcVCjz48v1sIEY20_GFWkJr1UJwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c 02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_JF0_ Jw1lIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7 CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v2 6r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf9x0J UXiSdUUUUU= X-CM-SenderInfo: qtrwiiyqvtljo62m3hxhgxhubq/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The former patch "defer 6pack kfree after unregister_netdev" reorders the kfree of two buffer after the unregister_netdev to prevent the race condition. It also adds free_netdev() function in sixpack_close(), which is a direct copy from the similar code in mkiss_close(). However, in sixpack driver, the flag needs_free_netdev is set to true in sp_setup(), hence the unregister_netdev() will free the netdev automatically. Therefore, as the sp is netdev_priv, use-after-free occurs. This patch removes the needs_free_netdev = true and just let the free_netdev to finish this deallocation task. Signed-off-by: Lin Ma --- drivers/net/hamradio/6pack.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c index bfdf89e54752..8a19a06b505d 100644 --- a/drivers/net/hamradio/6pack.c +++ b/drivers/net/hamradio/6pack.c @@ -306,7 +306,6 @@ static void sp_setup(struct net_device *dev) { /* Finish setting up the DEVICE info. */ dev->netdev_ops = &sp_netdev_ops; - dev->needs_free_netdev = true; dev->mtu = SIXP_MTU; dev->hard_header_len = AX25_MAX_HEADER_LEN; dev->header_ops = &ax25_header_ops; -- 2.33.1