From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757656Ab2GRAJv (ORCPT ); Tue, 17 Jul 2012 20:09:51 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:48276 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755465Ab2GRAEu (ORCPT ); Tue, 17 Jul 2012 20:04:50 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Pawel Moll , Mike Turquette Subject: [ 28/37] clk: Check parent for NULL in clk_change_rate Date: Tue, 17 Jul 2012 17:03:05 -0700 Message-Id: <20120717232433.716856099@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.1.362.g242cab3 In-Reply-To: <20120717232431.399005532@linuxfoundation.org> References: <20120717232455.GA5994@kroah.com> <20120717232431.399005532@linuxfoundation.org> User-Agent: quilt/0.60-20.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg KH 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pawel Moll commit bf47b4fd8f9f81cd5ce40e1945c6334d088226d1 upstream. clk_change_rate() is accessing parent's rate without checking if the parent exists at all. In case of root clocks this will cause NULL pointer dereference. This patch follows what clk_calc_new_rates() does in such situation. Signed-off-by: Pawel Moll Signed-off-by: Mike Turquette Signed-off-by: Greg Kroah-Hartman --- drivers/clk/clk.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -834,18 +834,21 @@ static void clk_change_rate(struct clk * { struct clk *child; unsigned long old_rate; + unsigned long best_parent_rate = 0; struct hlist_node *tmp; old_rate = clk->rate; + if (clk->parent) + best_parent_rate = clk->parent->rate; + if (clk->ops->set_rate) clk->ops->set_rate(clk->hw, clk->new_rate); if (clk->ops->recalc_rate) - clk->rate = clk->ops->recalc_rate(clk->hw, - clk->parent->rate); + clk->rate = clk->ops->recalc_rate(clk->hw, best_parent_rate); else - clk->rate = clk->parent->rate; + clk->rate = best_parent_rate; if (clk->notifier_count && old_rate != clk->rate) __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);