From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 273326AA0; Tue, 5 Dec 2023 03:19:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kM8doIrx" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 635BAC433C8; Tue, 5 Dec 2023 03:19:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1701746356; bh=dl4tGQZHeHw/NDgSP7t+OMYS1qLgZHjYAMPLl8ZWbNo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kM8doIrxYT1uBIK7yB9W256P4ramkTHsEX3YFLLhvMi/TOo7dcWdh05LvneDLFQ+x m32Lneawsvq2WFYyZ2X1heBDpn3zT3OkKT8oxlOvDHHyhZJELSTf6ZeljObcIDtA7i Fob1cxu8imO1ADYiX7munSv+OLoEOJgvhWjJWfsE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yoshihiro Shimoda , Sergey Shtylyov , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.14 28/30] ravb: Fix races between ravb_tx_timeout_work() and net related ops Date: Tue, 5 Dec 2023 12:16:35 +0900 Message-ID: <20231205031513.160565562@linuxfoundation.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231205031511.476698159@linuxfoundation.org> References: <20231205031511.476698159@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yoshihiro Shimoda [ Upstream commit 9870257a0a338cd8d6c1cddab74e703f490f6779 ] Fix races between ravb_tx_timeout_work() and functions of net_device_ops and ethtool_ops by using rtnl_trylock() and rtnl_unlock(). Note that since ravb_close() is under the rtnl lock and calls cancel_work_sync(), ravb_tx_timeout_work() should calls rtnl_trylock(). Otherwise, a deadlock may happen in ravb_tx_timeout_work() like below: CPU0 CPU1 ravb_tx_timeout() schedule_work() ... __dev_close_many() // Under rtnl lock ravb_close() cancel_work_sync() // Waiting ravb_tx_timeout_work() rtnl_lock() // This is possible to cause a deadlock If rtnl_trylock() fails, rescheduling the work with sleep for 1 msec. Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper") Signed-off-by: Yoshihiro Shimoda Reviewed-by: Sergey Shtylyov Link: https://lore.kernel.org/r/20231127122420.3706751-1-yoshihiro.shimoda.uh@renesas.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/renesas/ravb_main.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index 4acea1ab60008..4db3495ef3370 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -1484,6 +1484,12 @@ static void ravb_tx_timeout_work(struct work_struct *work) struct net_device *ndev = priv->ndev; int error; + if (!rtnl_trylock()) { + usleep_range(1000, 2000); + schedule_work(&priv->work); + return; + } + netif_tx_stop_all_queues(ndev); /* Stop PTP Clock driver */ @@ -1516,7 +1522,7 @@ static void ravb_tx_timeout_work(struct work_struct *work) */ netdev_err(ndev, "%s: ravb_dmac_init() failed, error %d\n", __func__, error); - return; + goto out_unlock; } ravb_emac_init(ndev); @@ -1526,6 +1532,9 @@ static void ravb_tx_timeout_work(struct work_struct *work) ravb_ptp_init(ndev, priv->pdev); netif_tx_start_all_queues(ndev); + +out_unlock: + rtnl_unlock(); } /* Packet transmit function for Ethernet AVB */ -- 2.42.0