From: Shivani Bhardwaj <shivani@oisf.net>
Date: Wed, 4 Jan 2023 06:30:13 +0000 (+0530)
Subject: decode/udp: fix payload_len calculation
X-Git-Tag: suricata-7.0.0-rc1~63
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f941ceae2be883596a3571ec9046ea884d3f3f85;p=thirdparty%2Fsuricata.git

decode/udp: fix payload_len calculation

Fix payload_len calculation post removal of the condition that returned
error code if the length to the decode fn did not match the length of
header from the UDP packet.

Bug 5379
---

diff --git a/src/decode-udp.c b/src/decode-udp.c
index 13c665cdd8..1ecaf54f6f 100644
--- a/src/decode-udp.c
+++ b/src/decode-udp.c
@@ -56,11 +56,16 @@ static int DecodeUDPPacket(ThreadVars *t, Packet *p, const uint8_t *pkt, uint16_
         return -1;
     }
 
+    if (unlikely(UDP_GET_LEN(p) < UDP_HEADER_LEN)) {
+        ENGINE_SET_INVALID_EVENT(p, UDP_LEN_INVALID);
+        return -1;
+    }
+
     SET_UDP_SRC_PORT(p,&p->sp);
     SET_UDP_DST_PORT(p,&p->dp);
 
     p->payload = (uint8_t *)pkt + UDP_HEADER_LEN;
-    p->payload_len = len - UDP_HEADER_LEN;
+    p->payload_len = UDP_GET_LEN(p) - UDP_HEADER_LEN;
 
     p->proto = IPPROTO_UDP;