From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753868AbcBXOZY (ORCPT ); Wed, 24 Feb 2016 09:25:24 -0500 Received: from vm1.sequanux.org ([188.165.36.56]:35566 "EHLO vm1.sequanux.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751441AbcBXOZW (ORCPT ); Wed, 24 Feb 2016 09:25:22 -0500 From: Simon Guinot To: Jesse Barnes , Alan Cox Cc: Vincent Pelletier , Linus Torvalds , Giel van Schijndel , Vincent Donnefort , Yoann Sculo , Linus Walleij , linux-kernel@vger.kernel.org, Simon Guinot , stable@vger.kernel.org Subject: [PATCH] kernel/resource.c: ensure parent is not freed in __request_region() Date: Wed, 24 Feb 2016 15:25:18 +0100 Message-Id: <1456323918-27487-1-git-send-email-simon.guinot@sequanux.org> X-Mailer: git-send-email 2.1.4 In-Reply-To: <56CC9489.7060706@virtuousgeek.org> References: <56CC9489.7060706@virtuousgeek.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The commit 59ceeaaf355fa0fb16558ef7c24413c804932ada ("kernel/resource.c: fix muxed resource handling in __request_region()") don't address properly the case where the current parent resource has been freed while sleeping, waiting for a muxed resource to be available. This patch fixes the issue by resetting the parent pointer to the root parent resource when sleeping is needed. Signed-off-by: Simon Guinot Cc: stable@vger.kernel.org --- kernel/resource.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/resource.c b/kernel/resource.c index 3669d1bfc425..14a7f9d66259 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1052,16 +1052,17 @@ static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); /** * __request_region - create a new busy resource region - * @parent: parent resource descriptor + * @root: root resource descriptor * @start: resource start address * @n: resource region size * @name: reserving caller's ID string * @flags: IO resource flags */ -struct resource * __request_region(struct resource *parent, +struct resource * __request_region(struct resource *root, resource_size_t start, resource_size_t n, const char *name, int flags) { + struct resource *parent = root; DECLARE_WAITQUEUE(wait, current); struct resource *res = alloc_resource(GFP_KERNEL); @@ -1089,6 +1090,7 @@ struct resource * __request_region(struct resource *parent, } } if (conflict->flags & flags & IORESOURCE_MUXED) { + parent = root; add_wait_queue(&muxed_resource_wait, &wait); write_unlock(&resource_lock); set_current_state(TASK_UNINTERRUPTIBLE); -- 2.1.4