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
| ||
|
Message-ID: <035e3423-c003-3de9-0805-2091b9efb45d@oracle.com> Date: Tue, 30 May 2023 11:30:01 -0500 From: michael.christie@...cle.com To: Stefano Garzarella <sgarzare@...hat.com> Cc: "Michael S. Tsirkin" <mst@...hat.com>, syzbot <syzbot+d0d442c22fa8db45ff0e@...kaller.appspotmail.com>, jasowang@...hat.com, kvm@...r.kernel.org, linux-kernel@...r.kernel.org, netdev@...r.kernel.org, syzkaller-bugs@...glegroups.com, virtualization@...ts.linux-foundation.org, stefanha@...hat.com Subject: Re: [syzbot] [kvm?] [net?] [virt?] general protection fault in vhost_work_queue On 5/30/23 11:17 AM, Stefano Garzarella wrote: > On Tue, May 30, 2023 at 11:09:09AM -0500, Mike Christie wrote: >> On 5/30/23 11:00 AM, Stefano Garzarella wrote: >>> I think it is partially related to commit 6e890c5d5021 ("vhost: use >>> vhost_tasks for worker threads") and commit 1a5f8090c6de ("vhost: move >>> worker thread fields to new struct"). Maybe that commits just >>> highlighted the issue and it was already existing. >> >> See my mail about the crash. Agree with your analysis about worker->vtsk >> not being set yet. It's a bug from my commit where I should have not set >> it so early or I should be checking for >> >> if (dev->worker && worker->vtsk) >> >> instead of >> >> if (dev->worker) > > Yes, though, in my opinion the problem may persist depending on how the > instructions are reordered. Ah ok. > > Should we protect dev->worker() with an RCU to be safe? For those multiple worker patchsets Jason had asked me about supporting where we don't have a worker while we are swapping workers around. To do that I had added rcu around the dev->worker. I removed it in later patchsets because I didn't think anyone would use it. rcu would work for your case and for what Jason had requested.
Powered by blists - more mailing lists