Messages in this thread | | | Date | Thu, 24 Oct 2019 12:31:34 +0200 | From | Steffen Klassert <> | Subject | Re: [PATCH v2 1/1] xfrm : lock input tasklet skb queue |
| |
On Tue, Oct 22, 2019 at 05:22:04PM -0700, Tom Rix wrote: > On PREEMPT_RT_FULL while running netperf, a corruption > of the skb queue causes an oops. > > This appears to be caused by a race condition here > __skb_queue_tail(&trans->queue, skb); > tasklet_schedule(&trans->tasklet); > Where the queue is changed before the tasklet is locked by > tasklet_schedule. > > The fix is to use the skb queue lock. > > This is the original work of Joerg Vehlow <joerg.vehlow@aox-tech.de> > https://lkml.org/lkml/2019/9/9/111 > xfrm_input: Protect queue with lock > > During the skb_queue_splice_init the tasklet could have been preempted > and __skb_queue_tail called, which led to an inconsistent queue. > > ifdefs for CONFIG_PREEMPT_RT_FULL added to reduce runtime effects > on the normal kernel.
Has Herbert commented on your initial patch, please fix PREEMPT_RT_FULL instead. There are certainly many more codepaths that take such assumptions. You can not fix this by distributing a spin_lock_irqsave here and there.
| |