| Message ID | 20161128234353.4262-1-diproiettod@ovn.org |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Mon, 2016-11-28 at 15:43 -0800, Daniele Di Proietto wrote: > If nf_ct_frag6_gather() returns an error other than -EINPROGRESS, it > means that we still have a reference to the skb. We should free it > before returning from handle_fragments, as stated in the comment above. > > Fixes: daaa7d647f81 ("netfilter: ipv6: avoid nf_iterate recursion") > CC: Florian Westphal <fw@strlen.de> > CC: Pravin B Shelar <pshelar@ovn.org> > CC: Joe Stringer <joe@ovn.org> > Signed-off-by: Daniele Di Proietto <diproiettod@ovn.org> > --- > net/openvswitch/conntrack.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c > index 31045ef..fecefa2 100644 > --- a/net/openvswitch/conntrack.c > +++ b/net/openvswitch/conntrack.c > @@ -370,8 +370,11 @@ static int handle_fragments(struct net *net, struct sw_flow_key *key, > skb_orphan(skb); > memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); > err = nf_ct_frag6_gather(net, skb, user); > - if (err) > + if (err) { > + if (err != -EINPROGRESS) > + kfree_skb(skb); > return err; > + } > > key->ip.proto = ipv6_hdr(skb)->nexthdr; > ovs_cb.mru = IP6CB(skb)->frag_max_size; Interesting, have you followed the "GPF in eth_header" thread today ? In a nutshell, we want a complete patch, not something that would solve part of the problem.
Eric Dumazet <eric.dumazet@gmail.com> wrote: > On Mon, 2016-11-28 at 15:43 -0800, Daniele Di Proietto wrote: > > If nf_ct_frag6_gather() returns an error other than -EINPROGRESS, it > > means that we still have a reference to the skb. We should free it > > before returning from handle_fragments, as stated in the comment above. > > > > Fixes: daaa7d647f81 ("netfilter: ipv6: avoid nf_iterate recursion") > > CC: Florian Westphal <fw@strlen.de> > > CC: Pravin B Shelar <pshelar@ovn.org> > > CC: Joe Stringer <joe@ovn.org> > > Signed-off-by: Daniele Di Proietto <diproiettod@ovn.org> > > --- > > net/openvswitch/conntrack.c | 5 ++++- > > 1 file changed, 4 insertions(+), 1 deletion(-) > > > > diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c > > index 31045ef..fecefa2 100644 > > --- a/net/openvswitch/conntrack.c > > +++ b/net/openvswitch/conntrack.c > > @@ -370,8 +370,11 @@ static int handle_fragments(struct net *net, struct sw_flow_key *key, > > skb_orphan(skb); > > memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); > > err = nf_ct_frag6_gather(net, skb, user); > > - if (err) > > + if (err) { > > + if (err != -EINPROGRESS) > > + kfree_skb(skb); > > return err; > > + } > > > > key->ip.proto = ipv6_hdr(skb)->nexthdr; > > ovs_cb.mru = IP6CB(skb)->frag_max_size; > > Interesting, have you followed the "GPF in eth_header" thread today ? > > In a nutshell, we want a complete patch, not something that would solve > part of the problem. I think this patch is fine, intent seems to be to only take fully reassembled skb, rather than a stray fragment (ovs does NOT seem to call handle_fragments in case skb is already known to not contain a fragment header, afaics). I'll send a patch for the GPF in eth_header thing soon.
On 28 November 2016 at 16:45, Florian Westphal <fw@strlen.de> wrote: > Eric Dumazet <eric.dumazet@gmail.com> wrote: >> On Mon, 2016-11-28 at 15:43 -0800, Daniele Di Proietto wrote: >> > If nf_ct_frag6_gather() returns an error other than -EINPROGRESS, it >> > means that we still have a reference to the skb. We should free it >> > before returning from handle_fragments, as stated in the comment above. >> > >> > Fixes: daaa7d647f81 ("netfilter: ipv6: avoid nf_iterate recursion") >> > CC: Florian Westphal <fw@strlen.de> >> > CC: Pravin B Shelar <pshelar@ovn.org> >> > CC: Joe Stringer <joe@ovn.org> >> > Signed-off-by: Daniele Di Proietto <diproiettod@ovn.org> >> > --- >> > net/openvswitch/conntrack.c | 5 ++++- >> > 1 file changed, 4 insertions(+), 1 deletion(-) >> > >> > diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c >> > index 31045ef..fecefa2 100644 >> > --- a/net/openvswitch/conntrack.c >> > +++ b/net/openvswitch/conntrack.c >> > @@ -370,8 +370,11 @@ static int handle_fragments(struct net *net, struct sw_flow_key *key, >> > skb_orphan(skb); >> > memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); >> > err = nf_ct_frag6_gather(net, skb, user); >> > - if (err) >> > + if (err) { >> > + if (err != -EINPROGRESS) >> > + kfree_skb(skb); >> > return err; >> > + } >> > >> > key->ip.proto = ipv6_hdr(skb)->nexthdr; >> > ovs_cb.mru = IP6CB(skb)->frag_max_size; >> >> Interesting, have you followed the "GPF in eth_header" thread today ? >> >> In a nutshell, we want a complete patch, not something that would solve >> part of the problem. > > I think this patch is fine, intent seems to be to only take fully reassembled > skb, rather than a stray fragment (ovs does NOT seem to call handle_fragments > in case skb is already known to not contain a fragment header, afaics). Correct, this is used in OVS only for fragmented packets and this function either morphs the skb into the full skb fragment chain, or steals/frees the skb. > I'll send a patch for the GPF in eth_header thing soon.
On Mon, Nov 28, 2016 at 3:43 PM, Daniele Di Proietto <diproiettod@ovn.org> wrote: > If nf_ct_frag6_gather() returns an error other than -EINPROGRESS, it > means that we still have a reference to the skb. We should free it > before returning from handle_fragments, as stated in the comment above. > > Fixes: daaa7d647f81 ("netfilter: ipv6: avoid nf_iterate recursion") > CC: Florian Westphal <fw@strlen.de> > CC: Pravin B Shelar <pshelar@ovn.org> > CC: Joe Stringer <joe@ovn.org> > Signed-off-by: Daniele Di Proietto <diproiettod@ovn.org> > --- > net/openvswitch/conntrack.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c > index 31045ef..fecefa2 100644 > --- a/net/openvswitch/conntrack.c > +++ b/net/openvswitch/conntrack.c > @@ -370,8 +370,11 @@ static int handle_fragments(struct net *net, struct sw_flow_key *key, > skb_orphan(skb); > memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); > err = nf_ct_frag6_gather(net, skb, user); > - if (err) > + if (err) { > + if (err != -EINPROGRESS) > + kfree_skb(skb); > return err; > + } > This fixes the code. But the patch is adding yet another skb-kfree in conntrack code. we could simplify it by reusing error handling in do_execute_actions(). If you think that is too complicated for stable branch, I am fine with this patch going in as it is.
On Tue, Nov 29, 2016 at 12:54 AM, Daniele Di Proietto <diproiettod@ovn.org> wrote: > > > 2016-11-28 23:39 GMT-08:00 Pravin Shelar <pshelar@ovn.org>: >> >> On Mon, Nov 28, 2016 at 3:43 PM, Daniele Di Proietto >> <diproiettod@ovn.org> wrote: >> > If nf_ct_frag6_gather() returns an error other than -EINPROGRESS, it >> > means that we still have a reference to the skb. We should free it >> > before returning from handle_fragments, as stated in the comment above. >> > >> > Fixes: daaa7d647f81 ("netfilter: ipv6: avoid nf_iterate recursion") >> > CC: Florian Westphal <fw@strlen.de> >> > CC: Pravin B Shelar <pshelar@ovn.org> >> > CC: Joe Stringer <joe@ovn.org> >> > Signed-off-by: Daniele Di Proietto <diproiettod@ovn.org> >> > --- >> > net/openvswitch/conntrack.c | 5 ++++- >> > 1 file changed, 4 insertions(+), 1 deletion(-) >> > >> > diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c >> > index 31045ef..fecefa2 100644 >> > --- a/net/openvswitch/conntrack.c >> > +++ b/net/openvswitch/conntrack.c >> > @@ -370,8 +370,11 @@ static int handle_fragments(struct net *net, struct >> > sw_flow_key *key, >> > skb_orphan(skb); >> > memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); >> > err = nf_ct_frag6_gather(net, skb, user); >> > - if (err) >> > + if (err) { >> > + if (err != -EINPROGRESS) >> > + kfree_skb(skb); >> > return err; >> > + } >> > >> >> This fixes the code. But the patch is adding yet another skb-kfree in >> conntrack code. we could simplify it by reusing error handling in >> do_execute_actions(). >> If you think that is too complicated for stable branch, I am fine with >> this patch going in as it is. > > > I thought it was simpler to handle this here rather than changing the > interface of > handle_fragments() and ovs_ct_execute(). Also this is more similar to the v4 > case, > where ip_defrag() frees the skb in case of error. > > What do you think? I agree this is simple enough for stable branch. I will check if ct action error handling could be simplified bit. Acked-by: Pravin B Shelar <pshelar@ovn.org>
From: Daniele Di Proietto <diproiettod@ovn.org> Date: Mon, 28 Nov 2016 15:43:53 -0800 > If nf_ct_frag6_gather() returns an error other than -EINPROGRESS, it > means that we still have a reference to the skb. We should free it > before returning from handle_fragments, as stated in the comment above. > > Fixes: daaa7d647f81 ("netfilter: ipv6: avoid nf_iterate recursion") > CC: Florian Westphal <fw@strlen.de> > CC: Pravin B Shelar <pshelar@ovn.org> > CC: Joe Stringer <joe@ovn.org> > Signed-off-by: Daniele Di Proietto <diproiettod@ovn.org> Applied, thanks.
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c index 31045ef..fecefa2 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -370,8 +370,11 @@ static int handle_fragments(struct net *net, struct sw_flow_key *key, skb_orphan(skb); memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); err = nf_ct_frag6_gather(net, skb, user); - if (err) + if (err) { + if (err != -EINPROGRESS) + kfree_skb(skb); return err; + } key->ip.proto = ipv6_hdr(skb)->nexthdr; ovs_cb.mru = IP6CB(skb)->frag_max_size;
If nf_ct_frag6_gather() returns an error other than -EINPROGRESS, it means that we still have a reference to the skb. We should free it before returning from handle_fragments, as stated in the comment above. Fixes: daaa7d647f81 ("netfilter: ipv6: avoid nf_iterate recursion") CC: Florian Westphal <fw@strlen.de> CC: Pravin B Shelar <pshelar@ovn.org> CC: Joe Stringer <joe@ovn.org> Signed-off-by: Daniele Di Proietto <diproiettod@ovn.org> --- net/openvswitch/conntrack.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)