lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 27 Mar 2014 10:37:32 -0700 From: Jesse Gross <jesse@...ira.com> To: Pravin Shelar <pshelar@...ira.com>, Jesse Gross <jesse@...ira.com>, netdev <netdev@...r.kernel.org>, openvswitch <dev@...nvswitch.org> Subject: Re: [PATCH net v2] openvswitch: fix a possible deadlock and lockdep warning On Thu, Mar 27, 2014 at 10:33 AM, Flavio Leitner <fbl@...hat.com> wrote: > On Thu, Mar 27, 2014 at 10:19:23AM -0700, Pravin Shelar wrote: >> On Thu, Mar 27, 2014 at 7:05 AM, Flavio Leitner <fbl@...hat.com> wrote: >> > There are two problematic situations. >> > >> > A deadlock can happen when is_percpu is false because it can get >> > interrupted while holding the spinlock. Then it executes >> > ovs_flow_stats_update() in softirq context which tries to get >> > the same lock. >> > >> > The second sitation is that when is_percpu is true, the code >> > correctly disables BH but only for the local CPU, so the >> > following can happen when locking the remote CPU without >> > disabling BH: >> > >> > CPU#0 CPU#1 >> > ovs_flow_stats_get() >> > stats_read() >> > +->spin_lock remote CPU#1 ovs_flow_stats_get() >> > | <interrupted> stats_read() >> > | ... +--> spin_lock remote CPU#0 >> > | | <interrupted> >> > | ovs_flow_stats_update() | ... >> > | spin_lock local CPU#0 <--+ ovs_flow_stats_update() >> > +---------------------------------- spin_lock local CPU#1 >> > >> > This patch disables BH for both cases fixing the deadlocks. >> >> This bug is already fixed in OVS. > > Could you point me to the commit? I am not finding anything > recent. This is the commit: commit 9d73c9cac76ba557fdac4a89c1b7eafe132b85a3 Author: Pravin B Shelar <pshelar@...ira.com> Date: Tue Dec 17 15:43:30 2013 -0800 datapath: Fix deadlock during stats update. I thought that I had sent it in the most recent batch of changes for net but it looks like I missed it. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists