From: Mark Andrews <marka@isc.org>
Date: Wed, 8 Mar 2023 05:38:11 +0000 (+1100)
Subject: Add additional contraints to dns_rdata_checksvcb
X-Git-Tag: v9.19.12~91^2
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e37c9702aee05f82e7552e6518992065ff8ce67b;p=thirdparty%2Fbind9.git

Add additional contraints to dns_rdata_checksvcb

REQUIRE that rdata->type is dns_rdatatype_svcb to detect when
dns_rdata_checksvcb is called with the wrong rdata type.  There are
no code paths that currently pass the wrong rdata to dns_rdata_checksvcb.

This was found by GCC 12 static analysis.
---

diff --git a/lib/dns/include/dns/rdata.h b/lib/dns/include/dns/rdata.h
index 338af3a3a0b..1ff135e697c 100644
--- a/lib/dns/include/dns/rdata.h
+++ b/lib/dns/include/dns/rdata.h
@@ -806,7 +806,7 @@ dns_rdata_checksvcb(const dns_name_t *owner, const dns_rdata_t *rdata);
  *
  * Requires:
  *\li	'owner' is a valid name.
- *\li	'rdata' is a valid, non-empty rdata.
+ *\li	'rdata' is a valid, non-empty SVCB rdata.
  *
  * Returns:
  *\li	#ISC_R_SUCCESS		-- success, the data is valid
diff --git a/lib/dns/rdata.c b/lib/dns/rdata.c
index 7ecc4a9a4d6..d90ef212f44 100644
--- a/lib/dns/rdata.c
+++ b/lib/dns/rdata.c
@@ -2435,6 +2435,7 @@ dns_rdata_checksvcb(const dns_name_t *owner, const dns_rdata_t *rdata) {
 
 	REQUIRE(owner != NULL);
 	REQUIRE(rdata != NULL);
+	REQUIRE(rdata->type == dns_rdatatype_svcb);
 	REQUIRE(DNS_RDATA_VALIDFLAGS(rdata));
 
 	result = dns_rdata_tostruct(rdata, &svcb, NULL);