From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752370AbaE0LTj (ORCPT ); Tue, 27 May 2014 07:19:39 -0400 Received: from mail-we0-f177.google.com ([74.125.82.177]:57332 "EHLO mail-we0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751868AbaE0LTg (ORCPT ); Tue, 27 May 2014 07:19:36 -0400 From: Grant Likely Subject: Re: [PATCH] of: handle NULL node in of_get_next_available_child To: Florian Fainelli , devicetree@vger.kernel.org Cc: Florian Fainelli , Daniel Mack , Rob Herring , open list In-Reply-To: <1400874192-29400-1-git-send-email-f.fainelli@gmail.com> References: <1400874192-29400-1-git-send-email-f.fainelli@gmail.com> Date: Tue, 27 May 2014 12:19:30 +0100 Message-Id: <20140527111930.696AAC4156C@trevor.secretlab.ca> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 23 May 2014 12:43:11 -0700, Florian Fainelli wrote: > Add an early check for the node argument in > of_get_next_available_child() to avoid dereferencing a NULL node pointer > a few lines after. > > CC: Daniel Mack > Signed-off-by: Florian Fainelli Is there a bug that exposed this path? I'd like some more justification before merging this patch, particularly considering of_get_next_child() doesn't check for it either, but you're not modifying that function. g. > --- > drivers/of/base.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/of/base.c b/drivers/of/base.c > index e67b308819c9..9a71bfac78ae 100644 > --- a/drivers/of/base.c > +++ b/drivers/of/base.c > @@ -746,6 +746,9 @@ struct device_node *of_get_next_available_child(const struct device_node *node, > struct device_node *next; > unsigned long flags; > > + if (!node) > + return NULL; > + > raw_spin_lock_irqsave(&devtree_lock, flags); > next = prev ? prev->sibling : node->child; > for (; next; next = next->sibling) { > -- > 1.9.1 >