From 9c1f74400c04267dea4f1bd7f62de8ba5e8d2b0e Mon Sep 17 00:00:00 2001
From: Mark Andrews <marka@isc.org>
Date: Thu, 28 Nov 2019 10:24:12 +1100
Subject: [PATCH 4/4] rdataset_setownercase and rdataset_getownercase need to
 obtain a node lock

(cherry picked from commit 637b2c4e517b466900a8c00b52f7a15727e12ae9)
(cherry picked from commit 1c61f129c3b12071723a2154d33f74628bf80998)
---
 lib/dns/rbtdb.c | 35 ++++++++++++++++++++++++++++-------
 1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
index d3bb8d7fe7..199ff08011 100644
--- a/lib/dns/rbtdb.c
+++ b/lib/dns/rbtdb.c
@@ -10109,11 +10109,18 @@ setownercase(rdatasetheader_t *header, const dns_name_t *name) {
 
 static void
 rdataset_setownercase(dns_rdataset_t *rdataset, const dns_name_t *name) {
+	dns_rbtdb_t *rbtdb = rdataset->private1;
+	dns_rbtnode_t *rbtnode = rdataset->private2;
 	unsigned char *raw = rdataset->private3;        /* RDATASLAB */
 	rdatasetheader_t *header;
 
 	header = (struct rdatasetheader *)(raw - sizeof(*header));
+
+	NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
+		  isc_rwlocktype_write);
 	setownercase(header, name);
+	NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
+		    isc_rwlocktype_write);
 }
 
 static const unsigned char charmask[] = {
@@ -10188,6 +10195,8 @@ static unsigned char maptolower[] = {
 
 static void
 rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) {
+	dns_rbtdb_t *rbtdb = rdataset->private1;
+	dns_rbtnode_t *rbtnode = rdataset->private2;
 	const unsigned char *raw = rdataset->private3;        /* RDATASLAB */
 	const rdatasetheader_t *header;
 	unsigned int i, j;
@@ -10196,8 +10205,12 @@ rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) {
 
 	header = (const struct rdatasetheader *)(raw - sizeof(*header));
 
-	if (!CASESET(header))
-		return;
+	NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
+		  isc_rwlocktype_read);
+
+	if (!CASESET(header)) {
+		goto unlock;
+	}
 
 #if 0
 	/*
@@ -10210,10 +10223,13 @@ rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) {
 		 */
 		if (name->ndata[i] >= 0x61 && name->ndata[i] <= 0x7a &&
 		    (header->upper[i/8] & (1 << (i%8))) != 0)
+		{
 			name->ndata[i] &= ~0x20; /* clear the lower case bit */
-		else if (name->ndata[i] >= 0x41 && name->ndata[i] <= 0x5a &&
-			 (header->upper[i/8] & (1 << (i%8))) == 0)
+		} else if (name->ndata[i] >= 0x41 && name->ndata[i] <= 0x5a &&
+			   (header->upper[i/8] & (1 << (i%8))) == 0)
+		{
 			name->ndata[i] |= 0x20; /* set the lower case bit */
+		}
 	}
 #else
 	if (ISC_LIKELY(CASEFULLYLOWER(header))) {
@@ -10236,7 +10252,7 @@ rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) {
 			c = *bp;
 			*bp++ = maptolower[c];
 		}
-		return;
+		goto unlock;
 	}
 
 	i = 0;
@@ -10257,8 +10273,9 @@ rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) {
 		}
 	}
 
-	if (ISC_UNLIKELY(i == name->length))
-		return;
+	if (ISC_UNLIKELY(i == name->length)) {
+		goto unlock;
+	}
 
 	bits = ~(header->upper[j]);
 
@@ -10272,6 +10289,10 @@ rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) {
 		bits >>= 1;
 	}
 #endif
+
+ unlock:
+	NODE_UNLOCK(&rbtdb->node_locks[rbtnode->locknum].lock,
+		    isc_rwlocktype_read);
 }
 
 /*%
-- 
2.21.0