From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20111102221456.513177008@clark.kroah.org> Date: Wed, 02 Nov 2011 15:14:36 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jiri Kosina , Rusty Russell Subject: [070/107] kmod: prevent kmod_loop_msg overflow in __request_module() In-Reply-To: <20111102221600.GA26650@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 2.6.32-longterm review patch. If anyone has any objections, please let us know. ------------------ From: Jiri Kosina 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: Greg Kroah-Hartman --- kernel/kmod.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -106,10 +106,12 @@ int __request_module(bool wait, const ch 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; }