From: Victor Julien <vjulien@oisf.net>
Date: Sat, 20 Apr 2024 10:57:41 +0000 (+0200)
Subject: decode/tcp: improve pointer hygene
X-Git-Tag: suricata-8.0.0-beta1~1362
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=86a363b1bcf478f19ab355efb3ad1a40e4d24997;p=thirdparty%2Fsuricata.git

decode/tcp: improve pointer hygene

Avoid NULL pointer calculations.
---

diff --git a/src/decode-tcp.c b/src/decode-tcp.c
index 558d005605..dd03f794d9 100644
--- a/src/decode-tcp.c
+++ b/src/decode-tcp.c
@@ -138,12 +138,11 @@ static void DecodeTCPOptions(Packet *p, const uint8_t *pkt, uint16_t pktlen)
                     break;
                 case TCP_OPT_SACK:
                     SCLogDebug("SACK option, len %u", olen);
-                    if ((olen != 2) &&
-                           (olen < TCP_OPT_SACK_MIN_LEN ||
-                            olen > TCP_OPT_SACK_MAX_LEN ||
-                            !((olen - 2) % 8 == 0)))
-                    {
-                        ENGINE_SET_EVENT(p,TCP_OPT_INVALID_LEN);
+                    if (olen == 2) {
+                        /* useless, but common empty SACK record */
+                    } else if (olen < TCP_OPT_SACK_MIN_LEN || olen > TCP_OPT_SACK_MAX_LEN ||
+                               !((olen - 2) % 8 == 0)) {
+                        ENGINE_SET_EVENT(p, TCP_OPT_INVALID_LEN);
                     } else {
                         if (p->l4.vars.tcp.sack_set) {
                             ENGINE_SET_EVENT(p,TCP_OPT_DUPLICATE);