[sr-dev] git:5.0:93539394: core: better protection against invalid name lookup in DNS caching support

[Henning Westerholt]

Module: kamailio
Branch: 5.0
Commit: 93539394b22a1c755821b09574b93d72d34d7689
URL: https://github.com/kamailio/kamailio/commit/93539394b22a1c755821b09574b93d72d34d7689

Author: Henning Westerholt <hw at kamailio.org>
Committer: Henning Westerholt <hw at kamailio.org>
Date: 2018-06-17T17:25:58+02:00

core: better protection against invalid name lookup in DNS caching support

(cherry picked from commit 74847c386f627ba89a0cb282e85d653388d45e24)

---

Modified: src/core/dns_cache.c

---

Diff:  https://github.com/kamailio/kamailio/commit/93539394b22a1c755821b09574b93d72d34d7689.diff
Patch: https://github.com/kamailio/kamailio/commit/93539394b22a1c755821b09574b93d72d34d7689.patch

---

diff --git a/src/core/dns_cache.c b/src/core/dns_cache.c
index 5d35c52dee..04f230b7cc 100644
--- a/src/core/dns_cache.c
+++ b/src/core/dns_cache.c
@@ -536,6 +536,13 @@ inline static struct dns_hash_entry* _dns_hash_find(str* name, int type,
 	ret=0;
 	now=get_ticks_raw();
 	*err=0;
+
+	/* just in case that e.g. the VIA parser get confused */
+	if(unlikely(!name->s || name->len <= 0)) {
+		LM_ERR("invalid name, no cache lookup possible\n");
+		*err=-1;
+		return 0;
+	}
 again:
 	*h=dns_hash_no(name->s, name->len, type);
 #ifdef DNS_CACHE_DEBUG