From: Mark Andrews <marka@isc.org>
Date: Wed, 24 Jun 2020 03:42:30 +0000 (+1000)
Subject: Address potential thread issues:
X-Git-Tag: v9.17.3~38^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=51f08d20954f7eb5601dc7aca0cfa80d438db107;p=thirdparty%2Fbind9.git

Address potential thread issues:

Assign and then check node for NULL to address another thread
changing radix->head in the meantime.

Move 'node != NULL' check into while loop test to silence cppcheck
false positive.

Fix pointer != NULL style.
---

diff --git a/lib/isc/radix.c b/lib/isc/radix.c
index 72416a61a59..fccad5baae1 100644
--- a/lib/isc/radix.c
+++ b/lib/isc/radix.c
@@ -232,15 +232,16 @@ isc_radix_search(isc_radix_tree_t *radix, isc_radix_node_t **target,
 
 	*target = NULL;
 
-	if (radix->head == NULL) {
+	node = radix->head;
+
+	if (node == NULL) {
 		return (ISC_R_NOTFOUND);
 	}
 
-	node = radix->head;
 	addr = isc_prefix_touchar(prefix);
 	bitlen = prefix->bitlen;
 
-	while (node->bit < bitlen) {
+	while (node != NULL && node->bit < bitlen) {
 		if (node->prefix) {
 			stack[cnt++] = node;
 		}
@@ -251,13 +252,9 @@ isc_radix_search(isc_radix_tree_t *radix, isc_radix_node_t **target,
 		} else {
 			node = node->l;
 		}
-
-		if (node == NULL) {
-			break;
-		}
 	}
 
-	if (node && node->prefix) {
+	if (node != NULL && node->prefix) {
 		stack[cnt++] = node;
 	}