| Message ID | 4D595745.7070505@trash.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
Le lundi 14 février 2011 à 17:24 +0100, Patrick McHardy a écrit : > Am 14.02.2011 16:50, schrieb Eric Dumazet: > > Le lundi 14 février 2011 à 16:18 +0100, Jan Engelhardt a écrit : > >> On Monday 2011-02-14 16:11, Eric Dumazet wrote: > >> > >>> Le lundi 14 février 2011 à 16:58 +0200, Avi Kivity a écrit : > >>>> We see severe memory corruption in kvm while used in conjunction with > >>>> bridge/netfilter. Enabling slab debugging points the finger at a > >>>> netfilter chain invoked from the bridge code. > >>>> > >>>> Can someone take a look? > >>>> > >>>> https://bugzilla.kernel.org/show_bug.cgi?id=27052 > >> > >> Maybe looks familiar to https://lkml.org/lkml/2011/2/3/147 > > > > Are you sure Jan ? > > > > IMHO it looks like in your case, a NULL ->hook() is called, from > > nf_iterate() > > > > BTW, list_for_each_continue_rcu() really should be converted to > > list_for_each_entry_continue_rcu() > > > > This is a bit ugly : > > > > list_for_each_continue_rcu(*i, head) { > > struct nf_hook_ops *elem = (struct nf_hook_ops *)*i; > > > > Also, I wonder if RCU rules are respected in nf_iterate(). > > For example this line is really suspicious : > > > > *i = (*i)->prev; > > Yeah, that definitely looks wrong. How about this instead? > This patch seems fine to me, thanks ! Acked-by: Eric Dumazet <eric.dumazet@gmail.com> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 14.02.2011 17:29, schrieb Eric Dumazet: > Le lundi 14 février 2011 à 17:24 +0100, Patrick McHardy a écrit : >>> Also, I wonder if RCU rules are respected in nf_iterate(). >>> For example this line is really suspicious : >>> >>> *i = (*i)->prev; >> >> Yeah, that definitely looks wrong. How about this instead? >> > > This patch seems fine to me, thanks ! > > Acked-by: Eric Dumazet <eric.dumazet@gmail.com> THanks Eric, I've queued the patch for 2.6.38. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Le lundi 14 février 2011 à 17:37 +0100, Patrick McHardy a écrit : > Am 14.02.2011 17:29, schrieb Eric Dumazet: > > Le lundi 14 février 2011 à 17:24 +0100, Patrick McHardy a écrit : > >>> Also, I wonder if RCU rules are respected in nf_iterate(). > >>> For example this line is really suspicious : > >>> > >>> *i = (*i)->prev; > >> > >> Yeah, that definitely looks wrong. How about this instead? > >> > > > > This patch seems fine to me, thanks ! > > > > Acked-by: Eric Dumazet <eric.dumazet@gmail.com> > > THanks Eric, I've queued the patch for 2.6.38. I am not sure, but I guess nf_reinject() needs a fix too ;) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 14.02.2011 17:48, schrieb Eric Dumazet: > Le lundi 14 février 2011 à 17:37 +0100, Patrick McHardy a écrit : >> Am 14.02.2011 17:29, schrieb Eric Dumazet: >>> Le lundi 14 février 2011 à 17:24 +0100, Patrick McHardy a écrit : >>>>> Also, I wonder if RCU rules are respected in nf_iterate(). >>>>> For example this line is really suspicious : >>>>> >>>>> *i = (*i)->prev; >>>> >>>> Yeah, that definitely looks wrong. How about this instead? >>>> >>> >>> This patch seems fine to me, thanks ! >>> >>> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> >> >> THanks Eric, I've queued the patch for 2.6.38. > > I am not sure, but I guess nf_reinject() needs a fix too ;) I agree. That one looks uglier though, I guess we'll have to iterate through all hooks to note the previous one. I'll take care of that once Dave has pulled the last fix since I already sent out the pull request. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/netfilter/core.c b/net/netfilter/core.c index 1e00bf7..899b71c 100644 --- a/net/netfilter/core.c +++ b/net/netfilter/core.c @@ -133,6 +133,7 @@ unsigned int nf_iterate(struct list_head *head, /* Optimization: we don't need to hold module reference here, since function can't sleep. --RR */ +repeat: verdict = elem->hook(hook, skb, indev, outdev, okfn); if (verdict != NF_ACCEPT) { #ifdef CONFIG_NETFILTER_DEBUG @@ -145,7 +146,7 @@ unsigned int nf_iterate(struct list_head *head, #endif if (verdict != NF_REPEAT) return verdict; - *i = (*i)->prev; + goto repeat; } } return NF_ACCEPT;