From patchwork Mon Aug 8 03:42:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lin Ma X-Patchwork-Id: 12938460 X-Patchwork-Delegate: kuba@kernel.org 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A102BC3F6B0 for ; Mon, 8 Aug 2022 03:43:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235451AbiHHDnJ (ORCPT ); Sun, 7 Aug 2022 23:43:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229744AbiHHDnG (ORCPT ); Sun, 7 Aug 2022 23:43:06 -0400 Received: from zju.edu.cn (spam.zju.edu.cn [61.164.42.155]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F19FCE0C; Sun, 7 Aug 2022 20:43:03 -0700 (PDT) Received: from localhost.localdomain (unknown [10.12.77.33]) by mail-app4 (Coremail) with SMTP id cS_KCgBHv04qhvBiSHF2Ag--.32873S4; Mon, 08 Aug 2022 11:42:34 +0800 (CST) From: Lin Ma To: michael.hennerich@analog.com, alex.aring@gmail.com, stefan@datenfreihafen.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-wpan@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Lin Ma Subject: [PATCH v0] ieee802154/adf7242: defer destroy_workqueue call Date: Mon, 8 Aug 2022 11:42:24 +0800 Message-Id: <20220808034224.12642-1-linma@zju.edu.cn> X-Mailer: git-send-email 2.36.1 MIME-Version: 1.0 X-CM-TRANSID: cS_KCgBHv04qhvBiSHF2Ag--.32873S4 X-Coremail-Antispam: 1UD129KBjvJXoW7tw4rJw1DWF4rur4kur1UAwb_yoW8Xw4DpF WrZ345Cw40qr4UJw4FkF48XFyruan5t3y8u3W3Wwsavw1kXrnFyr1xCayjgryrGFW8ZFWS vFn8tr15uwn8CrDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvl1xkIjI8I6I8E6xAIw20EY4v20xvaj40_Wr0E3s1l1IIY67AE w4v_Jr0_Jr4l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2 IY67AKxVWDJVCq3wA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2 z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcV Aq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1j 6r18McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64 vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8cxan2IY04v7MxAIw28I cxkI7VAKI48JMxAIw28IcVCjz48v1sIEY20_GFWkJr1UJwCFx2IqxVCFs4IE7xkEbVWUJV W8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI8E67AF67kF 1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67AKxVWUJVWUCwCI42IY6x IIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvE x4A2jsIE14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvj DU0xZFpf9x0JUdHUDUUUUU= X-CM-SenderInfo: qtrwiiyqvtljo62m3hxhgxhubq/ Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org There is a possible race condition (use-after-free) like below (FREE) | (USE) adf7242_remove | adf7242_channel cancel_delayed_work_sync | destroy_workqueue (1) | adf7242_cmd_rx | mod_delayed_work (2) | The root cause for this race is that the upper layer (ieee802154) is unaware of this detaching event and the function adf7242_channel can be called without any checks. To fix this, we can add a flag write at the beginning of adf7242_remove and add flag check in adf7242_channel. Or we can just defer the destructive operation like other commit 3e0588c291d6 ("hamradio: defer ax25 kfree after unregister_netdev") which let the ieee802154_unregister_hw() to handle the synchronization. This patch takes the second option. Fixes: 58e9683d1475 ("net: ieee802154: adf7242: Fix OCL calibration runs") Signed-off-by: Lin Ma Acked-by: Michael Hennerich --- drivers/net/ieee802154/adf7242.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ieee802154/adf7242.c b/drivers/net/ieee802154/adf7242.c index 6afdf1622944..efcc45aef508 100644 --- a/drivers/net/ieee802154/adf7242.c +++ b/drivers/net/ieee802154/adf7242.c @@ -1310,10 +1310,11 @@ static void adf7242_remove(struct spi_device *spi) debugfs_remove_recursive(lp->debugfs_root); + ieee802154_unregister_hw(lp->hw); + cancel_delayed_work_sync(&lp->work); destroy_workqueue(lp->wqueue); - - ieee802154_unregister_hw(lp->hw); + mutex_destroy(&lp->bmux); ieee802154_free_hw(lp->hw); }