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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT 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 1C068C43219 for ; Fri, 3 May 2019 10:08:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E977D2075C for ; Fri, 3 May 2019 10:08:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727479AbfECKIT (ORCPT ); Fri, 3 May 2019 06:08:19 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:54085 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725816AbfECKIT (ORCPT ); Fri, 3 May 2019 06:08:19 -0400 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 512) id B2436802D6; Fri, 3 May 2019 12:08:06 +0200 (CEST) Date: Fri, 3 May 2019 12:08:16 +0200 From: Pavel Machek To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Wen Yang , Anirudha Sarangi , John Linn , "David S. Miller" , Michal Simek , netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "Sasha Levin (Microsoft)" Subject: Re: [PATCH 4.19 46/72] net: xilinx: fix possible object reference leak Message-ID: <20190503100816.GD5834@amd> References: <20190502143333.437607839@linuxfoundation.org> <20190502143337.107638265@linuxfoundation.org> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="a2FkP9tdjPU2nyhF" Content-Disposition: inline In-Reply-To: <20190502143337.107638265@linuxfoundation.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --a2FkP9tdjPU2nyhF Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu 2019-05-02 17:21:08, Greg Kroah-Hartman wrote: > [ Upstream commit fa3a419d2f674b431d38748cb58fb7da17ee8949 ] >=20 > The call to of_parse_phandle returns a node pointer with refcount > incremented thus it must be explicitly decremented after the last > usage. >=20 > Detected by coccinelle with the following warnings: > ./drivers/net/ethernet/xilinx/xilinx_axienet_main.c:1624:1-7: ERROR: miss= ing of_node_put; acquired a node pointer with refcount incremented on line = 1569, but without a corresponding object release within this function. >=20 > Signed-off-by: Wen Yang > Cc: Anirudha Sarangi > Cc: John Linn > Cc: "David S. Miller" > Cc: Michal Simek > Cc: netdev@vger.kernel.org > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: David S. Miller > Signed-off-by: Sasha Levin (Microsoft) Bug is real, but fix is horrible. This already uses gotos for error handling, so use them.... This fixes it up. Plus... I do not think these "of_node_put" fixes belong in stable. They are theoretical bugs; so we hold reference to device tree structure. a) it is small, b) it stays in memory, anyway. This does not fix any real problem. Pavel diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/ne= t/ethernet/xilinx/xilinx_axienet_main.c index 4041c75..490d440 100644 --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c @@ -1575,15 +1575,13 @@ static int axienet_probe(struct platform_device *pd= ev) ret =3D of_address_to_resource(np, 0, &dmares); if (ret) { dev_err(&pdev->dev, "unable to get DMA resource\n"); - of_node_put(np); - goto free_netdev; + goto free_netdev_put; } lp->dma_regs =3D devm_ioremap_resource(&pdev->dev, &dmares); if (IS_ERR(lp->dma_regs)) { dev_err(&pdev->dev, "could not map DMA regs\n"); ret =3D PTR_ERR(lp->dma_regs); - of_node_put(np); - goto free_netdev; + goto free_netdev_put; } lp->rx_irq =3D irq_of_parse_and_map(np, 1); lp->tx_irq =3D irq_of_parse_and_map(np, 0); @@ -1620,6 +1618,8 @@ static int axienet_probe(struct platform_device *pdev) =20 return 0; =20 +free_netdev_put: + of_node_put(np); free_netdev: free_netdev(ndev); =20 > --- > drivers/net/ethernet/xilinx/xilinx_axienet_main.c | 2 ++ > 1 file changed, 2 insertions(+) >=20 > diff --git a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c b/drivers/= net/ethernet/xilinx/xilinx_axienet_main.c > index f24f48f33802..7cfd7ff38e86 100644 > --- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c > +++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c > @@ -1574,12 +1574,14 @@ static int axienet_probe(struct platform_device *= pdev) > ret =3D of_address_to_resource(np, 0, &dmares); > if (ret) { > dev_err(&pdev->dev, "unable to get DMA resource\n"); > + of_node_put(np); > goto free_netdev; > } > lp->dma_regs =3D devm_ioremap_resource(&pdev->dev, &dmares); > if (IS_ERR(lp->dma_regs)) { > dev_err(&pdev->dev, "could not map DMA regs\n"); > ret =3D PTR_ERR(lp->dma_regs); > + of_node_put(np); > goto free_netdev; > } > lp->rx_irq =3D irq_of_parse_and_map(np, 1); --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --a2FkP9tdjPU2nyhF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAlzMExAACgkQMOfwapXb+vIrQACfRGO7B7c76iqFSkLanh93OYhc YB8AnjX80JqCdvKDKa6YoJRJg3pTE41w =GJN0 -----END PGP SIGNATURE----- --a2FkP9tdjPU2nyhF--