* [PATCH 1/3] netfilter: nf_ct_sip: handle non-linear skbs
2010-05-20 16:00 [PATCH 0/3] netfilter: netfilter fixes kaber
@ 2010-05-20 16:00 ` kaber
2010-05-20 16:00 ` [PATCH 2/3] netfilter: nf_conntrack: fix a race in __nf_conntrack_confirm against nf_ct_get_next_corpse() kaber
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: kaber @ 2010-05-20 16:00 UTC (permalink / raw)
To: davem; +Cc: netfilter-devel, netdev
From: Patrick McHardy <kaber@trash.net>
Handle non-linear skbs by linearizing them instead of silently failing.
Long term the helper should be fixed to either work with non-linear skbs
directly by using the string search API or work on a copy of the data.
Based on patch by Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
---
net/netfilter/nf_conntrack_sip.c | 12 ++++--------
1 files changed, 4 insertions(+), 8 deletions(-)
diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c
index b20f427..53d8922 100644
--- a/net/netfilter/nf_conntrack_sip.c
+++ b/net/netfilter/nf_conntrack_sip.c
@@ -1393,10 +1393,8 @@ static int sip_help_tcp(struct sk_buff *skb, unsigned int protoff,
nf_ct_refresh(ct, skb, sip_timeout * HZ);
- if (skb_is_nonlinear(skb)) {
- pr_debug("Copy of skbuff not supported yet.\n");
- return NF_ACCEPT;
- }
+ if (unlikely(skb_linearize(skb)))
+ return NF_DROP;
dptr = skb->data + dataoff;
datalen = skb->len - dataoff;
@@ -1455,10 +1453,8 @@ static int sip_help_udp(struct sk_buff *skb, unsigned int protoff,
nf_ct_refresh(ct, skb, sip_timeout * HZ);
- if (skb_is_nonlinear(skb)) {
- pr_debug("Copy of skbuff not supported yet.\n");
- return NF_ACCEPT;
- }
+ if (unlikely(skb_linearize(skb)))
+ return NF_DROP;
dptr = skb->data + dataoff;
datalen = skb->len - dataoff;
--
1.7.0.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/3] netfilter: nf_conntrack: fix a race in __nf_conntrack_confirm against nf_ct_get_next_corpse()
2010-05-20 16:00 [PATCH 0/3] netfilter: netfilter fixes kaber
2010-05-20 16:00 ` [PATCH 1/3] netfilter: nf_ct_sip: handle non-linear skbs kaber
@ 2010-05-20 16:00 ` kaber
2010-05-20 16:00 ` [PATCH 3/3] netfilter: fix description of expected checkentry return code on xt_target kaber
2010-05-21 6:12 ` [PATCH 0/3] netfilter: netfilter fixes David Miller
3 siblings, 0 replies; 5+ messages in thread
From: kaber @ 2010-05-20 16:00 UTC (permalink / raw)
To: davem; +Cc: netfilter-devel, netdev
From: Joerg Marx <joerg.marx@secunet.com>
This race was triggered by a 'conntrack -F' command running in parallel
to the insertion of a hash for a new connection. Losing this race led to
a dead conntrack entry effectively blocking traffic for a particular
connection until timeout or flushing the conntrack hashes again.
Now the check for an already dying connection is done inside the lock.
Signed-off-by: Joerg Marx <joerg.marx@secunet.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
---
include/net/netfilter/nf_conntrack_core.h | 2 +-
net/netfilter/nf_conntrack_core.c | 10 ++++++++++
2 files changed, 11 insertions(+), 1 deletions(-)
diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h
index dffde8e..3d7524f 100644
--- a/include/net/netfilter/nf_conntrack_core.h
+++ b/include/net/netfilter/nf_conntrack_core.h
@@ -61,7 +61,7 @@ static inline int nf_conntrack_confirm(struct sk_buff *skb)
int ret = NF_ACCEPT;
if (ct && ct != &nf_conntrack_untracked) {
- if (!nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct))
+ if (!nf_ct_is_confirmed(ct))
ret = __nf_conntrack_confirm(skb);
if (likely(ret == NF_ACCEPT))
nf_ct_deliver_cached_events(ct);
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index b83c530..eeeb8bc 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -424,6 +424,16 @@ __nf_conntrack_confirm(struct sk_buff *skb)
spin_lock_bh(&nf_conntrack_lock);
+ /* We have to check the DYING flag inside the lock to prevent
+ a race against nf_ct_get_next_corpse() possibly called from
+ user context, else we insert an already 'dead' hash, blocking
+ further use of that particular connection -JM */
+
+ if (unlikely(nf_ct_is_dying(ct))) {
+ spin_unlock_bh(&nf_conntrack_lock);
+ return NF_ACCEPT;
+ }
+
/* See if there's one in the list already, including reverse:
NAT could have grabbed it without realizing, since we're
not in the hash. If there is, we lost race. */
--
1.7.0.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/3] netfilter: fix description of expected checkentry return code on xt_target
2010-05-20 16:00 [PATCH 0/3] netfilter: netfilter fixes kaber
2010-05-20 16:00 ` [PATCH 1/3] netfilter: nf_ct_sip: handle non-linear skbs kaber
2010-05-20 16:00 ` [PATCH 2/3] netfilter: nf_conntrack: fix a race in __nf_conntrack_confirm against nf_ct_get_next_corpse() kaber
@ 2010-05-20 16:00 ` kaber
2010-05-21 6:12 ` [PATCH 0/3] netfilter: netfilter fixes David Miller
3 siblings, 0 replies; 5+ messages in thread
From: kaber @ 2010-05-20 16:00 UTC (permalink / raw)
To: davem; +Cc: netfilter-devel, netdev
From: Luciano Coelho <luciano.coelho@nokia.com>
The text describing the return codes that are expected on calls to
checkentry() was incorrect. Instead of returning true or false, or an error
code, it should return 0 or an error code.
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
---
include/linux/netfilter/x_tables.h | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index c2ee5d8..c00cc0c 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -333,7 +333,7 @@ struct xt_target {
/* Called when user tries to insert an entry of this type:
hook_mask is a bitmask of hooks from which it can be
called. */
- /* Should return true or false, or an error code (-Exxxx). */
+ /* Should return 0 on success or an error code otherwise (-Exxxx). */
int (*checkentry)(const struct xt_tgchk_param *);
/* Called when entry of this type deleted. */
--
1.7.0.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 0/3] netfilter: netfilter fixes
2010-05-20 16:00 [PATCH 0/3] netfilter: netfilter fixes kaber
` (2 preceding siblings ...)
2010-05-20 16:00 ` [PATCH 3/3] netfilter: fix description of expected checkentry return code on xt_target kaber
@ 2010-05-21 6:12 ` David Miller
3 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2010-05-21 6:12 UTC (permalink / raw)
To: kaber; +Cc: netfilter-devel, netdev
From: kaber@trash.net
Date: Thu, 20 May 2010 18:00:43 +0200
> following are three fixes for netfilter:
>
> - handling of non-linear skbs in the SIP conntrack helper. This fixes tracking
> failures when running on the same machine as a SIP application that is
> producing non-linear skbs. Long term this should be fixed by using the string
> search API, but that is a bigger piece of work.
>
> - fix for a race condition in nf_conntrack that might lead to conntrack entries
> marked as dead entering the hash tables, blocking new connections with similar
> keys.
>
> - a fix for an incorrect comment about the checkentry return conventions.
>
> Please apply or pull from:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6.git master
Pulled, thanks Patrick.
^ permalink raw reply [flat|nested] 5+ messages in thread