[NETFILTER 04/05]: nf_nat: fix MASQUERADE crash on device down

[Patrick McHardy <kaber@trash.net>]

[NETFILTER]: nf_nat: fix MASQUERADE crash on device down

Check the return value of nfct_nat() in device_cmp(), we might very well
have non NAT conntrack entries as well (Netfilter bugzilla #528).

Signed-off-by: Martin Josefsson <gandalf@wlug.westbo.se>
Signed-off-by: Patrick McHardy <kaber@trash.net>

---
commit 36263425185d6993ca8af49ad6e7d1af66846d9c
tree 99089b7efc4c5c76d7afdc07f82537b9c525a799
parent d137d1a8688da1e81415c8a6a33d283210408bf0
author Martin Josefsson <gandalf@wlug.westbo.se> Thu, 04 Jan 2007 19:25:56 +0100
committer Patrick McHardy <kaber@trash.net> Thu, 04 Jan 2007 19:25:56 +0100

 net/ipv4/netfilter/ipt_MASQUERADE.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c
index 28b9233..d669685 100644
--- a/net/ipv4/netfilter/ipt_MASQUERADE.c
+++ b/net/ipv4/netfilter/ipt_MASQUERADE.c
@@ -127,10 +127,13 @@ #endif
 static inline int
 device_cmp(struct ip_conntrack *i, void *ifindex)
 {
+	int ret;
 #ifdef CONFIG_NF_NAT_NEEDED
 	struct nf_conn_nat *nat = nfct_nat(i);
+
+	if (!nat)
+		return 0;
 #endif
-	int ret;
 
 	read_lock_bh(&masq_lock);
 #ifdef CONFIG_NF_NAT_NEEDED