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=-17.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 45AD6C433ED for ; Wed, 5 May 2021 09:18:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18512613C7 for ; Wed, 5 May 2021 09:18:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232256AbhEEJTW (ORCPT ); Wed, 5 May 2021 05:19:22 -0400 Received: from lb2-smtp-cloud7.xs4all.net ([194.109.24.28]:55097 "EHLO lb2-smtp-cloud7.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231987AbhEEJTQ (ORCPT ); Wed, 5 May 2021 05:19:16 -0400 Received: from cust-b5b5937f ([IPv6:fc0c:c16d:66b8:757f:c639:739b:9d66:799d]) by smtp-cloud7.xs4all.net with ESMTPA id eDfalkaaVyEWweDfelumJB; Wed, 05 May 2021 11:18:19 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xs4all.nl; s=s2; t=1620206299; bh=uFqvRwOLsMa7SIQMsQ5/JoCIwOaiv0b6VkBg1dtVN3c=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type:From: Subject; b=EyiCUfh4g4r1oXOpTnrOc7cvDVCT4mizeUXhPkrLHVqd4HCUPXYnS/Csu4Ty4YjQL o83XyTq5H0kACQ2mruR5HAtwkXiaRlDkkd4QDmA4Ygx1mkUL0YSfi3MdxovTiVC2AY VwBQq575GZHxs/MGPdMkhxhCtRAPde8TC+87Sp8uQuaXcUwMUuWriWlJj7k3b/r3hZ lXIezVvUFELfHHiSQp0/lUg7r8SngbWshr8giYVATUKpTK2hI0OqJEjSto6BGeFV9o Iix2SRAqqBxvAa1FD/00Z6qVCo8TRneI5cPuqILXTFpzEvQQ5r3FDTPghDf7m31LNt rae268bThwPJw== Subject: Re: [PATCH] media: cobalt: fix null-ptr-deref when there is no PCI bridge To: Tong Zhang , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210424005206.261622-1-ztong0001@gmail.com> From: Hans Verkuil Message-ID: Date: Wed, 5 May 2021 11:18:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: <20210424005206.261622-1-ztong0001@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfEoTHaoLL+uzMYkeMiBfZMc9OFcCGcXwTwWbX1s2vdLVpxIYkt+xcS3wDYUm+2AX4ee9AHwZwSPFMKMXneINE/QyNY5p9O5ZQc17K5MuafpXlAiHg7UK kLiZsHESNKJfCzOoWWrvKZEAToXGqADzdeldVCMOj3GfnwPXL+0nOlfptMv7eges425RrR0YXrKwUjeX8TeAbKXiDZMkJuSBA4l1eXs9jPr9qWGv/4rQoJAZ 9cXRYLyC/wpYYpfqzIUY8IADRMewg0wUSeEZ1bXuXdPmutKrFUx5QEKoOiWS63DF2RQOdAwl7PFZDklLwme1kA== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24/04/2021 02:52, Tong Zhang wrote: > the PCI bridge might be NULL, so we'd better check before use it > > [ 1.870569] RIP: 0010:pcie_bus_link_get_lanes.isra.0+0x26/0x59 [cobalt] > [ 1.875880] Call Trace: > [ 1.876013] cobalt_probe.cold+0x1be/0xc11 [cobalt] > [ 1.876683] pci_device_probe+0x10f/0x1c0 How did you test this? With some virtualized PCI bus or something? I'm not sure how this can happen. Regards, Hans > > Signed-off-by: Tong Zhang > --- > drivers/media/pci/cobalt/cobalt-driver.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/media/pci/cobalt/cobalt-driver.c b/drivers/media/pci/cobalt/cobalt-driver.c > index 0695078ef812..5687ed4869ac 100644 > --- a/drivers/media/pci/cobalt/cobalt-driver.c > +++ b/drivers/media/pci/cobalt/cobalt-driver.c > @@ -189,6 +189,8 @@ void cobalt_pcie_status_show(struct cobalt *cobalt) > u32 capa; > u16 stat, ctrl; > > + if (!pci_bus_dev) > + return; > if (!pci_is_pcie(pci_dev) || !pci_is_pcie(pci_bus_dev)) > return; > > @@ -247,6 +249,8 @@ static unsigned pcie_bus_link_get_lanes(struct cobalt *cobalt) > struct pci_dev *pci_dev = cobalt->pci_dev->bus->self; > u32 link; > > + if (!pci_dev) > + return 0; > if (!pci_is_pcie(pci_dev)) > return 0; > pcie_capability_read_dword(pci_dev, PCI_EXP_LNKCAP, &link); >