From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750927AbdAMAqx (ORCPT ); Thu, 12 Jan 2017 19:46:53 -0500 Received: from mail-pf0-f172.google.com ([209.85.192.172]:32958 "EHLO mail-pf0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750781AbdAMAqw (ORCPT ); Thu, 12 Jan 2017 19:46:52 -0500 Subject: Re: [PATCH] PCI: iproc: fix kernel crash if dev->of_node not defined To: Abylay Ospan , Bjorn Helgaas , Ray Jui , Scott Branden , Jon Mason , bcm-kernel-feedback-list@broadcom.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <1484266817-6725-1-git-send-email-aospan@netup.ru> From: Ray Jui Message-ID: <5c51f96f-1c49-3768-d3ef-1deb40bef713@broadcom.com> Date: Thu, 12 Jan 2017 16:45:49 -0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:50.0) Gecko/20100101 Thunderbird/50.0 MIME-Version: 1.0 In-Reply-To: <1484266817-6725-1-git-send-email-aospan@netup.ru> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/12/2017 4:20 PM, Abylay Ospan wrote: > pcie->dev->of_node not always defined (NULL) and can cause crash: Ah I guess this can happen with the BCMA based platforms that do not use device tree for PCIe? > > [ 19.053195] Unable to handle kernel NULL pointer dereference at > virtual address 00000020 > [] (of_n_addr_cells) from [] > (iproc_pcie_setup+0x30c/0xce0) > > this patch adds sanity check to prevent crash. > > Signed-off-by: Abylay Ospan > --- > drivers/pci/host/pcie-iproc.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c > index 3ebc025..f2836a9 100644 > --- a/drivers/pci/host/pcie-iproc.c > +++ b/drivers/pci/host/pcie-iproc.c > @@ -952,6 +952,9 @@ static int pci_dma_range_parser_init(struct of_pci_range_parser *parser, > const int na = 3, ns = 2; > int rlen; > > + if (!node) > + return -ENOENT; > + Looks like a valid check to me. Acked-by: Ray Jui > parser->node = node; > parser->pna = of_n_addr_cells(node); > parser->np = parser->pna + na + ns; >