[PATCH net 02/12] ipvs: fix reversed sequence option serialization

[Pablo Neira Ayuso <pablo@netfilter.org>]

From: Kyle Zeng <kylebot@openai.com>

hton_seq() expects the host-order source first and the unaligned
network-order destination second. The version 1 sync sender passes these
arguments in reverse for both sequence blocks. This leaves 24 bytes of the
kmalloc-backed message unwritten. It may disclose stale heap data and
replace the live connection sequence state with values read from the
buffer.

Pass the connection sequence state as the source and the message payload as
the destination for both blocks.

Fixes: 986a07579533 ("IPVS: Backup, Change sending to Version 1 format")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Kyle Zeng <kylebot@openai.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/ipvs/ip_vs_sync.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_sync.c b/net/netfilter/ipvs/ip_vs_sync.c
index 1deb063cd72c..5383aeafb0ae 100644
--- a/net/netfilter/ipvs/ip_vs_sync.c
+++ b/net/netfilter/ipvs/ip_vs_sync.c
@@ -747,9 +747,9 @@ void ip_vs_sync_conn(struct netns_ipvs *ipvs, struct ip_vs_conn *cp, int pkts)
 	if (cp->flags & IP_VS_CONN_F_SEQ_MASK) {
 		*(p++) = IPVS_OPT_SEQ_DATA;
 		*(p++) = sizeof(struct ip_vs_sync_conn_options);
-		hton_seq((struct ip_vs_seq *)p, &cp->in_seq);
+		hton_seq(&cp->in_seq, (struct ip_vs_seq *)p);
 		p += sizeof(struct ip_vs_seq);
-		hton_seq((struct ip_vs_seq *)p, &cp->out_seq);
+		hton_seq(&cp->out_seq, (struct ip_vs_seq *)p);
 		p += sizeof(struct ip_vs_seq);
 	}
 	/* Handle pe data */
-- 
2.47.3