ipvs: remove IPS_NAT_MASK check to fix passive FTP

Julian Anastasov · ummakynes · commit 8a949fff0302 · 2018-02-28T19:48:26.000+01:00
The IPS_NAT_MASK check in 4.12 replaced previous check for nfct_nat() which was needed to fix a crash in 2.6.36-rc, see commit 7bcbf81 ("ipvs: avoid oops for passive FTP"). But as IPVS does not set the IPS_SRC_NAT and IPS_DST_NAT bits, checking for IPS_NAT_MASK prevents PASV response to be properly mangled and blocks the transfer. Remove the check as it is not needed after 3.12 commit 41d73ec ("netfilter: nf_conntrack: make sequence number adjustments usuable without NAT") which changes nfct_nat() with nfct_seqadj() and especially after 3.13 commit b25adce ("ipvs: correct usage/allocation of seqadj ext in ipvs"). Thanks to Li Shuang and Florian Westphal for reporting the problem! Reported-by: Li Shuang <shuali@redhat.com> Fixes: be7be6e ("netfilter: ipvs: fix incorrect conflict resolution") Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Simon Horman <horms@verge.net.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/ipvs/ip_vs_ftp.c b/net/netfilter/ipvs/ip_vs_ftp.c
@@ -260,7 +260,7 @@ static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp,
 		buf_len = strlen(buf);
 
 		ct = nf_ct_get(skb, &ctinfo);
-		if (ct && (ct->status & IPS_NAT_MASK)) {
+		if (ct) {
 			bool mangled;
 
 			/* If mangling fails this function will return 0
