From patchwork Fri Feb 15 03:10:05 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herton Ronaldo Krzesinski X-Patchwork-Id: 220584 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id AA28D2C0089 for ; Fri, 15 Feb 2013 14:10:22 +1100 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1U6Bgk-0006s5-O9; Fri, 15 Feb 2013 03:10:14 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1U6Bgi-0006ru-4i for kernel-team@lists.ubuntu.com; Fri, 15 Feb 2013 03:10:12 +0000 Received: from 200.139.121.114.dynamic.adsl.gvt.net.br ([200.139.121.114] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1U6Bge-0000iv-CF; Fri, 15 Feb 2013 03:10:09 +0000 From: Herton Ronaldo Krzesinski To: T Makphaibulchoke Subject: [ 3.5.y.z extended stable ] Patch "kernel/resource.c: fix stack overflow in" has been added to staging queue Date: Fri, 15 Feb 2013 01:10:05 -0200 Message-Id: <1360897805-14929-1-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 X-Extended-Stable: 3.5 Cc: Wei Yang , Paul Gortmaker , Jiri Slaby , Ram Pai , kernel-team@lists.ubuntu.com, Andrew Morton , Linus Torvalds X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled kernel/resource.c: fix stack overflow in to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Herton ------ From eada91d3628ac4496b6561b02036a23f2fcf652e Mon Sep 17 00:00:00 2001 From: T Makphaibulchoke Date: Thu, 4 Oct 2012 17:16:55 -0700 Subject: [PATCH] kernel/resource.c: fix stack overflow in __reserve_region_with_split() commit 4965f5667f36a95b41cda6638875bc992bd7d18b upstream. Using a recursive call add a non-conflicting region in __reserve_region_with_split() could result in a stack overflow in the case that the recursive calls are too deep. Convert the recursive calls to an iterative loop to avoid the problem. Tested on a machine containing 135 regions. The kernel no longer panicked with stack overflow. Also tested with code arbitrarily adding regions with no conflict, embedding two consecutive conflicts and embedding two non-consecutive conflicts. Signed-off-by: T Makphaibulchoke Reviewed-by: Ram Pai Cc: Paul Gortmaker Cc: Wei Yang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Jiri Slaby Signed-off-by: Herton Ronaldo Krzesinski --- kernel/resource.c | 50 ++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 38 insertions(+), 12 deletions(-) -- 1.7.9.5 diff --git a/kernel/resource.c b/kernel/resource.c index e1d2b8e..7de982e 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -758,6 +758,7 @@ static void __init __reserve_region_with_split(struct resource *root, struct resource *parent = root; struct resource *conflict; struct resource *res = kzalloc(sizeof(*res), GFP_ATOMIC); + struct resource *next_res = NULL; if (!res) return; @@ -767,21 +768,46 @@ static void __init __reserve_region_with_split(struct resource *root, res->end = end; res->flags = IORESOURCE_BUSY; - conflict = __request_resource(parent, res); - if (!conflict) - return; + while (1) { - /* failed, split and try again */ - kfree(res); + conflict = __request_resource(parent, res); + if (!conflict) { + if (!next_res) + break; + res = next_res; + next_res = NULL; + continue; + } - /* conflict covered whole area */ - if (conflict->start <= start && conflict->end >= end) - return; + /* conflict covered whole area */ + if (conflict->start <= res->start && + conflict->end >= res->end) { + kfree(res); + WARN_ON(next_res); + break; + } + + /* failed, split and try again */ + if (conflict->start > res->start) { + end = res->end; + res->end = conflict->start - 1; + if (conflict->end < end) { + next_res = kzalloc(sizeof(*next_res), + GFP_ATOMIC); + if (!next_res) { + kfree(res); + break; + } + next_res->name = name; + next_res->start = conflict->end + 1; + next_res->end = end; + next_res->flags = IORESOURCE_BUSY; + } + } else { + res->start = conflict->end + 1; + } + } - if (conflict->start > start) - __reserve_region_with_split(root, start, conflict->start-1, name); - if (conflict->end < end) - __reserve_region_with_split(root, conflict->end+1, end, name); } void __init reserve_region_with_split(struct resource *root,