Messages in this thread | | | Date | Thu, 4 Jan 2018 12:20:26 +0100 | From | Artem Savkov <> | Subject | Re: [PATCH] xfrm: init skb_head lock for transport-mode packets |
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On Thu, Jan 04, 2018 at 10:01:32PM +1100, Herbert Xu wrote: > On Thu, Jan 04, 2018 at 11:36:28AM +0100, Artem Savkov wrote: > > Commit acf568ee859f "xfrm: Reinject transport-mode packets through tasklet" > > adds an sk_buff_head queue, but never initializes trans->queue.lock, which > > results in a "spinlock bad magic" BUG on skb_queue_tail() call in > > xfrm_trans_queue. > > Use skb_queue_head_init() instead of __skb_queue_head_init() to properly > > initialize said lock. > > > > Signed-off-by: Artem Savkov <asavkov@redhat.com> > > Thanks for catching this. But we don't need the lock as this > is meant to be per-CPU only. So we should remove the locking > instead:
Right, thats a better solution.
Reported-and-tested-by: Artem Savkov <asavkov@redhat.com>
Thank you.
> ---8<--- > xfrm: Use __skb_queue_tail in xfrm_trans_queue > > We do not need locking in xfrm_trans_queue because it is designed > to use per-CPU buffers. However, the original code incorrectly > used skb_queue_tail which takes the lock. This patch switches > it to __skb_queue_tail instead. > > Reported-by: Artem Savkov <asavkov@redhat.com> > Fixes: acf568ee859f ("xfrm: Reinject transport-mode packets...") > Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> > > diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c > index 098f47a..1eb0bba 100644 > --- a/net/xfrm/xfrm_input.c > +++ b/net/xfrm/xfrm_input.c > @@ -511,7 +511,7 @@ int xfrm_trans_queue_net(struct net *net, struct sk_buff *skb, > > XFRM_TRANS_SKB_CB(skb)->finish = finish; > XFRM_TRANS_SKB_CB(skb)->net = net; > - skb_queue_tail(&trans->queue, skb); > + __skb_queue_tail(&trans->queue, skb); > tasklet_schedule(&trans->tasklet); > return 0; > }
-- Regards, Artem
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