From patchwork Tue May 26 18:53:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 225238 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1542BC433E2 for ; Tue, 26 May 2020 19:27:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DF037208B6 for ; Tue, 26 May 2020 19:27:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590521273; bh=FVRhLzacGoEhzd4mO/2FsiTrK9j4U0vluiHtXiSMJ1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RRjCnNdMvY/hpPYnfBACYVR9oNI7m6/RPzbtaIWg4oueM/RwWCuXe+9Mmrqe0b9pY WzlmgMvyLkpsv7hFxsrG3R9YfMyaqswBho2T9u0udy56upsLtoL1pizYtIRDmnEVGe zJaWpT+b5JT080Wnpu17cUM7BTmDh0TEDy7qT4vw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389725AbgEZTDr (ORCPT ); Tue, 26 May 2020 15:03:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:59122 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391252AbgEZTDq (ORCPT ); Tue, 26 May 2020 15:03:46 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EC7B420849; Tue, 26 May 2020 19:03:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1590519825; bh=FVRhLzacGoEhzd4mO/2FsiTrK9j4U0vluiHtXiSMJ1E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sfPa+2Jb29EczjX9LfKwxVp0WGgq8Mtz5cGHCTnCQxMOZBQvdhZHqNKW6tOGmE5up iKf4z68bWkc6gprw6XLEX2RWf5PVtizzD/MnY96PDr9fHnoOj+rDjHzEmDUfbCSGd1 n3iavfpTQxAkVsBSsk8Ogqg3PswLgFobSczNe5o8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxim Petrov , "David S. Miller" , Sasha Levin Subject: [PATCH 4.19 31/81] stmmac: fix pointer check after utilization in stmmac_interrupt Date: Tue, 26 May 2020 20:53:06 +0200 Message-Id: <20200526183930.897646125@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200526183923.108515292@linuxfoundation.org> References: <20200526183923.108515292@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Maxim Petrov [ Upstream commit f42234ffd531ca6b13d9da02faa60b72eccf8334 ] The paranoidal pointer check in IRQ handler looks very strange - it really protects us only against bogus drivers which request IRQ line with null pointer dev_id. However, the code fragment is incorrect because the dev pointer is used before the actual check which leads to undefined behavior. Remove the check to avoid confusing people with incorrect code. Signed-off-by: Maxim Petrov Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 9c7b1d8e8220..c41879a955b5 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3684,7 +3684,7 @@ static int stmmac_set_features(struct net_device *netdev, /** * stmmac_interrupt - main ISR * @irq: interrupt number. - * @dev_id: to pass the net device pointer. + * @dev_id: to pass the net device pointer (must be valid). * Description: this is the main driver interrupt service routine. * It can call: * o DMA service routine (to manage incoming frame reception and transmission @@ -3708,11 +3708,6 @@ static irqreturn_t stmmac_interrupt(int irq, void *dev_id) if (priv->irq_wake) pm_wakeup_event(priv->device, 0); - if (unlikely(!dev)) { - netdev_err(priv->dev, "%s: invalid dev pointer\n", __func__); - return IRQ_NONE; - } - /* Check if adapter is up */ if (test_bit(STMMAC_DOWN, &priv->state)) return IRQ_HANDLED;