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 X-Spam-Level: X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 7CB79C4363D for ; Fri, 25 Sep 2020 12:57:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2EE52206DB for ; Fri, 25 Sep 2020 12:57:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601038630; bh=y+GQbXTaidAAY0N1sPQ/gYgts01Bp6ydqL0LMW4IpvY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fI+eWNur2q6jXKoCP17avTLk1N0zSlZCVIgs1G1T0AN+TNgu0gYHcGEd/wx4gm0Ut AIuXFcRKnLCPloivvhOKzYX2bLrPg1IAmWZx8Ja28eGSMmdSwfuk3SFcYfK7qlR09n owEjNOImdHFALtw0dU9jMmmkxTSHKNLwcMDHcq10= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729156AbgIYMvH (ORCPT ); Fri, 25 Sep 2020 08:51:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:55026 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729129AbgIYMu6 (ORCPT ); Fri, 25 Sep 2020 08:50:58 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 D65202075E; Fri, 25 Sep 2020 12:50:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601038258; bh=y+GQbXTaidAAY0N1sPQ/gYgts01Bp6ydqL0LMW4IpvY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HRpGML6o5h7PwsOriBWoLjdwILPMxsKO9sZRnRqlATzDIIYB5fhXPQCco/p0nPusF ohhS6Oisg+xWuKRx4Vrh0B8alwDBNnofl8cd9HFDq2fcaawDLZ5oFL/ibRLHVKPswO TlTlbnYxme9Z7sKdka3TFf840i4ARz8q4by8GN2U= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Florian Fainelli , Andrew Lunn , "David S. Miller" Subject: [PATCH 5.8 39/56] net: phy: Avoid NPD upon phy_detach() when driver is unbound Date: Fri, 25 Sep 2020 14:48:29 +0200 Message-Id: <20200925124733.718921386@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200925124727.878494124@linuxfoundation.org> References: <20200925124727.878494124@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: Florian Fainelli [ Upstream commit c2b727df7caa33876e7066bde090f40001b6d643 ] If we have unbound the PHY driver prior to calling phy_detach() (often via phy_disconnect()) then we can cause a NULL pointer de-reference accessing the driver owner member. The steps to reproduce are: echo unimac-mdio-0:01 > /sys/class/net/eth0/phydev/driver/unbind ip link set eth0 down Fixes: cafe8df8b9bc ("net: phy: Fix lack of reference count on PHY driver") Signed-off-by: Florian Fainelli Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/phy/phy_device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -1631,7 +1631,8 @@ void phy_detach(struct phy_device *phyde phy_led_triggers_unregister(phydev); - module_put(phydev->mdio.dev.driver->owner); + if (phydev->mdio.dev.driver) + module_put(phydev->mdio.dev.driver->owner); /* If the device had no specific driver before (i.e. - it * was using the generic driver), we unbind the device