From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756528Ab2HOTu7 (ORCPT ); Wed, 15 Aug 2012 15:50:59 -0400 Received: from mail1.windriver.com ([147.11.146.13]:62947 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756552Ab2HOTuy (ORCPT ); Wed, 15 Aug 2012 15:50:54 -0400 From: Paul Gortmaker To: , CC: Jiri Kosina , Rusty Russell , Paul Gortmaker Subject: [v2.6.34-stable 082/165] kmod: prevent kmod_loop_msg overflow in __request_module() Date: Wed, 15 Aug 2012 15:47:06 -0400 Message-ID: <1345060109-9187-83-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.12.rc2 In-Reply-To: <1345060109-9187-1-git-send-email-paul.gortmaker@windriver.com> References: <1345060109-9187-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiri Kosina ------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. ------------------- commit 37252db6aa576c34fd794a5a54fb32d7a8b3a07a upstream. Due to post-increment in condition of kmod_loop_msg in __request_module(), the system log can be spammed by much more than 5 instances of the 'runaway loop' message if the number of events triggering it makes the kmod_loop_msg to overflow. Fix that by making sure we never increment it past the threshold. Signed-off-by: Jiri Kosina Signed-off-by: Rusty Russell Signed-off-by: Paul Gortmaker --- kernel/kmod.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/kmod.c b/kernel/kmod.c index bf0e231..f50a996 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -106,10 +106,12 @@ int __request_module(bool wait, const char *fmt, ...) atomic_inc(&kmod_concurrent); if (atomic_read(&kmod_concurrent) > max_modprobes) { /* We may be blaming an innocent here, but unlikely */ - if (kmod_loop_msg++ < 5) + if (kmod_loop_msg < 5) { printk(KERN_ERR "request_module: runaway loop modprobe %s\n", module_name); + kmod_loop_msg++; + } atomic_dec(&kmod_concurrent); return -ENOMEM; } -- 1.7.12.rc2