From nobody Thu Dec 18 13:02:08 2025 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 51DF5C32772 for ; Tue, 23 Aug 2022 08:42:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346910AbiHWImz (ORCPT ); Tue, 23 Aug 2022 04:42:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1347783AbiHWIlF (ORCPT ); Tue, 23 Aug 2022 04:41:05 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FD6B792E6; Tue, 23 Aug 2022 01:19:19 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 40619B81C4D; Tue, 23 Aug 2022 08:18:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8BE52C433C1; Tue, 23 Aug 2022 08:18:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1661242707; bh=xd9pSX2o4PEovPzwScjsz4aIA2Eq9p7JoyzIc20i9rQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qF4ZO91nB18E9CbYLnipxMoJ3hSZzVMJwT+HjqIVrHiD3D6IKq2mHEQwrY9loB0Xe xOAHGVd1c0yiHeR2EwmXM4LiGvLZJ/Y5QNXhZNbQ24UqbBrXAPFTXO4gy17hRS92ST BKPrd/IjmeK65XWsLKgsDaA2j3qEffop3CHyGcIo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ivan Vecera , Konrad Jankowski , Tony Nguyen Subject: [PATCH 5.19 175/365] iavf: Fix deadlock in initialization Date: Tue, 23 Aug 2022 10:01:16 +0200 Message-Id: <20220823080125.533399037@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220823080118.128342613@linuxfoundation.org> References: <20220823080118.128342613@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Ivan Vecera commit cbe9e51126305832cf407ee6bb556ce831488ffe upstream. Fix deadlock that occurs when iavf interface is a part of failover configuration. 1. Mutex crit_lock is taken at the beginning of iavf_watchdog_task() 2. Function iavf_init_config_adapter() is called when adapter state is __IAVF_INIT_CONFIG_ADAPTER 3. iavf_init_config_adapter() calls register_netdevice() that emits NETDEV_REGISTER event 4. Notifier function failover_event() then calls net_failover_slave_register() that calls dev_open() 5. dev_open() calls iavf_open() that tries to take crit_lock in end-less loop Stack trace: ... [ 790.251876] usleep_range_state+0x5b/0x80 [ 790.252547] iavf_open+0x37/0x1d0 [iavf] [ 790.253139] __dev_open+0xcd/0x160 [ 790.253699] dev_open+0x47/0x90 [ 790.254323] net_failover_slave_register+0x122/0x220 [net_failover] [ 790.255213] failover_slave_register.part.7+0xd2/0x180 [failover] [ 790.256050] failover_event+0x122/0x1ab [failover] [ 790.256821] notifier_call_chain+0x47/0x70 [ 790.257510] register_netdevice+0x20f/0x550 [ 790.258263] iavf_watchdog_task+0x7c8/0xea0 [iavf] [ 790.259009] process_one_work+0x1a7/0x360 [ 790.259705] worker_thread+0x30/0x390 To fix the situation we should check the current adapter state after first unsuccessful mutex_trylock() and return with -EBUSY if it is __IAVF_INIT_CONFIG_ADAPTER. Fixes: 226d528512cf ("iavf: fix locking of critical sections") Signed-off-by: Ivan Vecera Tested-by: Konrad Jankowski Signed-off-by: Tony Nguyen Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/intel/iavf/iavf_main.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/drivers/net/ethernet/intel/iavf/iavf_main.c +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c @@ -3989,8 +3989,17 @@ static int iavf_open(struct net_device * return -EIO; } =20 - while (!mutex_trylock(&adapter->crit_lock)) + while (!mutex_trylock(&adapter->crit_lock)) { + /* If we are in __IAVF_INIT_CONFIG_ADAPTER state the crit_lock + * is already taken and iavf_open is called from an upper + * device's notifier reacting on NETDEV_REGISTER event. + * We have to leave here to avoid dead lock. + */ + if (adapter->state =3D=3D __IAVF_INIT_CONFIG_ADAPTER) + return -EBUSY; + usleep_range(500, 1000); + } =20 if (adapter->state !=3D __IAVF_DOWN) { err =3D -EBUSY;