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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB3A5C433F5 for ; Mon, 21 Mar 2022 14:15:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349317AbiCUORI (ORCPT ); Mon, 21 Mar 2022 10:17:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349353AbiCUOIL (ORCPT ); Mon, 21 Mar 2022 10:08:11 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F1BB179417; Mon, 21 Mar 2022 07:02:44 -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 9DA31B816C8; Mon, 21 Mar 2022 14:02:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F059C340F2; Mon, 21 Mar 2022 14:02:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647871361; bh=kK0ExYZAsFXBMqVa2Gyws0IcFssO//gPc8Ps9AhPX5E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FsG9N5D4pym0LpAUPh6XLrr7zO9bpg5P1PhoBUO6y1FkCEKSCvLsBS4QVJULoOa0Y tRwseAkfTf1TWTzte5wfQtgECRo1NA91uHQWlRDiZgnvezioMD+S24BxEki0kTtsRn IbXtmih4bsk/iDgtBDPdtq6lHHVuMNZCn9nxQPDA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Niels Dossche , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.16 07/37] alx: acquire mutex for alx_reinit in alx_change_mtu Date: Mon, 21 Mar 2022 14:52:49 +0100 Message-Id: <20220321133221.507932995@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220321133221.290173884@linuxfoundation.org> References: <20220321133221.290173884@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Niels Dossche [ Upstream commit 46b348fd2d81a341b15fb3f3f986204b038f5c42 ] alx_reinit has a lockdep assertion that the alx->mtx mutex must be held. alx_reinit is called from two places: alx_reset and alx_change_mtu. alx_reset does acquire alx->mtx before calling alx_reinit. alx_change_mtu does not acquire this mutex, nor do its callers or any path towards alx_change_mtu. Acquire the mutex in alx_change_mtu. The issue was introduced when the fine-grained locking was introduced to the code to replace the RTNL. The same commit also introduced the lockdep assertion. Fixes: 4a5fe57e7751 ("alx: use fine-grained locking instead of RTNL") Signed-off-by: Niels Dossche Link: https://lore.kernel.org/r/20220310232707.44251-1-dossche.niels@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/atheros/alx/main.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/atheros/alx/main.c b/drivers/net/ethernet/atheros/alx/main.c index 4ad3fc72e74e..a89b93cb4e26 100644 --- a/drivers/net/ethernet/atheros/alx/main.c +++ b/drivers/net/ethernet/atheros/alx/main.c @@ -1181,8 +1181,11 @@ static int alx_change_mtu(struct net_device *netdev, int mtu) alx->hw.mtu = mtu; alx->rxbuf_size = max(max_frame, ALX_DEF_RXBUF_SIZE); netdev_update_features(netdev); - if (netif_running(netdev)) + if (netif_running(netdev)) { + mutex_lock(&alx->mtx); alx_reinit(alx); + mutex_unlock(&alx->mtx); + } return 0; } -- 2.34.1