[PATCH nf-next v4 2/4] netfilter: nf_conntrack_irc: use nf_ct_helper_parse_port()

[Rahul Chandelkar <rc@rexion.ai>]

parse_dcc() stored the result of simple_strtoul() directly into a u16
*port, so a DCC port above 65535 was silently truncated (e.g. 65537
became 1), creating a conntrack expectation for a port that never
appeared in the DCC command.

Use nf_ct_helper_parse_port(), which parses the length-delimited buffer
without relying on NUL termination and rejects port 0 and values above
65535.

Fixes: 869f37d8e48f ("[NETFILTER]: nf_conntrack/nf_nat: add IRC helper port")
Signed-off-by: Rahul Chandelkar <rc@rexion.ai>
---
 net/netfilter/nf_conntrack_irc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c
index 92360963757a..268ce7c1f9b2 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -88,7 +88,9 @@ static int parse_dcc(char *data, const char *data_end, __be32 *ip,
 		data++;
 	}
 
-	*port = simple_strtoul(data, &data, 10);
+	if (nf_ct_helper_parse_port(data, data_end - data, port, &data))
+		return -1;
+
 	*ad_end_p = data;
 
 	return 0;
-- 
2.43.0