From 65d8d329620973319b577e9a1b0ffad528a4df1f Mon Sep 17 00:00:00 2001
From: Stefano Brivio <sbrivio@redhat.com>
Date: Mon, 27 Feb 2023 03:05:26 +0100
Subject: [PATCH 05/20] tcp: Avoid false (but convoluted) positive Coverity
 CWE-476 warning

If there are no TCP options in the header, tcp_tap_handler() will
pass the corresponding pointer, fetched via packet_get(), as NULL to
tcp_conn_from_sock_finish(), which in turn indirectly calls
tcp_opt_get().

If there are no options, tcp_opt_get() will stop right away because
the option length is indicated as zero. However, if the logic is
complicated enough to follow for static checkers, adding an explicit
check against NULL in tcp_opt_get() is probably a good idea.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
(cherry picked from commit a1d5537741679c117b4c1a9b736ea2540a976eee)
---
 tcp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcp.c b/tcp.c
index c62fe44..a811b5e 100644
--- a/tcp.c
+++ b/tcp.c
@@ -1114,7 +1114,7 @@ static int tcp_opt_get(const char *opts, size_t len, uint8_t type_find,
 {
 	uint8_t type, optlen;
 
-	if (!len)
+	if (!opts || !len)
 		return -1;
 
 	for (; len >= 2; opts += optlen, len -= optlen) {
-- 
2.39.2