[PATCH] netfilter: Don't parse CTCP message if shorter than minimum length

[Sohom]

If the CTCP message is shorter than 10 + 21 + MINMATCHLEN
then exit early and don't parse the rest of the message.

Signed-off-by: Sohom <sohomdatta1+git@xxxxxxxxx>
---
 net/netfilter/nf_conntrack_irc.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_irc.c b/net/netfilter/nf_conntrack_irc.c
index 5703846bea3b..703b5a123cb5 100644
--- a/net/netfilter/nf_conntrack_irc.c
+++ b/net/netfilter/nf_conntrack_irc.c
@@ -157,8 +157,12 @@ static int help(struct sk_buff *skb, unsigned int protoff,
 	data = ib_ptr;
 	data_limit = ib_ptr + datalen;
 
+	if (data >= data_limit - (10 + 21 + MINMATCHLEN)) {
+		goto out;
+	}
+
 	/* Skip any whitespace */
-	while (data < data_limit - 10) {
+	while (data < data_limit) {
 		if (*data == ' ' || *data == '\r' || *data == '\n')
 			data++;
 		else
-- 
2.41.0