upstream/bind9
1
0
Fork 0
mirror of https://github.com/isc-projects/bind9.git synced 2026-03-19 09:09:36 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions

Fix reference counting in get_attached_entry

Browse source 
When get_attached_entry() encounters entry that would be expired, it
needs to get reference to the entry before calling maybe_expire_entry(),
so the ADB entry doesn't get destroyed inside the its own lock.
This commit is contained in:
Ondřej Surý 2022-12-06 15:59:35 +01:00 committed by Ondřej Surý
parent 406de85309
commit c2be97eeff
1 changed files with 8 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
lib/dns/adb.c
View file

@ -1358,15 +1358,18 @@ get_attached_name(dns_adb_t *adb, const dns_name_t *name, bool start_at_zone,
case ISC_R_NOTFOUND:
/* Allocate a new name and add it to the hash table. */
adbname = new_adbname(adb, name, start_at_zone);
dns_adbname_ref(adbname);
adbname->last_used = now;
result = isc_hashmap_add(adb->names, &hashval,
&adbname->key.key, adbname->key.size,
adbname);
INSIST(result == ISC_R_SUCCESS);
ISC_LIST_PREPEND(adb->names_lru, adbname, link);
adbname->last_used = now;
break;
case ISC_R_SUCCESS:
dns_adbname_ref(adbname);
LOCK(&adbname->lock);
if (adbname->last_used + ADB_STALE_MARGIN <= last_update) {
adbname->last_used = now;
@ -1384,8 +1387,6 @@ get_attached_name(dns_adb_t *adb, const dns_name_t *name, bool start_at_zone,
* expire_name() - the unused adbname stored in the hashtable and lru
* has always refcount == 1
*/
dns_adbname_ref(adbname);
UNLOCK(&adb->names_lock);
return (adbname);
@ -1424,16 +1425,19 @@ get_attached_entry(dns_adb_t *adb, isc_stdtime_t now,
create:
/* Allocate a new entry and add it to the hash table. */
adbentry = new_adbentry(adb, addr);
dns_adbentry_ref(adbentry);
adbentry->last_used = now;
result = isc_hashmap_add(adb->entries, &hashval,
&adbentry->sockaddr,
sizeof(adbentry->sockaddr), adbentry);
INSIST(result == ISC_R_SUCCESS);
ISC_LIST_PREPEND(adb->entries_lru, adbentry, link);
adbentry->last_used = now;
break;
}
case ISC_R_SUCCESS:
dns_adbentry_ref(adbentry);
LOCK(&adbentry->lock);
if (maybe_expire_entry(adbentry, now)) {
UNLOCK(&adbentry->lock);
@ -1451,7 +1455,6 @@ get_attached_entry(dns_adb_t *adb, isc_stdtime_t now,
default:
UNREACHABLE();
}
dns_adbentry_ref(adbentry);
UNLOCK(&adb->entries_lock);