Merge branch '4182-confidential-fix-races-in-dns-tsigkey-find-9.18' into 'v9.18.22-release'

[9.18] Address race in dns_tsigkey_find()

See merge request isc-private/bind9!622
This commit is contained in:
Michał Kępień 2024-01-05 10:30:14 +00:00
commit 346b26823c
2 changed files with 17 additions and 8 deletions

View file

@ -1,3 +1,6 @@
6314. [bug] Address race conditions in dns_tsigkey_find().
[GL #4182]
6312. [bug] Conversion from NSEC3 signed to NSEC signed could
temporarily put the zone into a state where it was
treated as unsigned until the NSEC chain was built.

View file

@ -1757,8 +1757,9 @@ isc_result_t
dns_tsigkey_find(dns_tsigkey_t **tsigkey, const dns_name_t *name,
const dns_name_t *algorithm, dns_tsig_keyring_t *ring) {
dns_tsigkey_t *key;
isc_stdtime_t now;
isc_result_t result;
isc_rwlocktype_t locktype = isc_rwlocktype_read;
isc_stdtime_t now;
REQUIRE(tsigkey != NULL);
REQUIRE(*tsigkey == NULL);
@ -1770,25 +1771,30 @@ dns_tsigkey_find(dns_tsigkey_t **tsigkey, const dns_name_t *name,
RWUNLOCK(&ring->lock, isc_rwlocktype_write);
isc_stdtime_get(&now);
RWLOCK(&ring->lock, isc_rwlocktype_read);
again:
RWLOCK(&ring->lock, locktype);
key = NULL;
result = dns_rbt_findname(ring->keys, name, 0, NULL, (void *)&key);
if (result == DNS_R_PARTIALMATCH || result == ISC_R_NOTFOUND) {
RWUNLOCK(&ring->lock, isc_rwlocktype_read);
RWUNLOCK(&ring->lock, locktype);
return (ISC_R_NOTFOUND);
}
if (algorithm != NULL && !dns_name_equal(key->algorithm, algorithm)) {
RWUNLOCK(&ring->lock, isc_rwlocktype_read);
RWUNLOCK(&ring->lock, locktype);
return (ISC_R_NOTFOUND);
}
if (key->inception != key->expire && isc_serial_lt(key->expire, now)) {
/*
* The key has expired.
*/
RWUNLOCK(&ring->lock, isc_rwlocktype_read);
RWLOCK(&ring->lock, isc_rwlocktype_write);
if (locktype == isc_rwlocktype_read) {
RWUNLOCK(&ring->lock, locktype);
locktype = isc_rwlocktype_write;
goto again;
}
remove_fromring(key);
RWUNLOCK(&ring->lock, isc_rwlocktype_write);
RWUNLOCK(&ring->lock, locktype);
return (ISC_R_NOTFOUND);
}
#if 0
@ -1803,7 +1809,7 @@ dns_tsigkey_find(dns_tsigkey_t **tsigkey, const dns_name_t *name,
}
#endif /* if 0 */
isc_refcount_increment(&key->refs);
RWUNLOCK(&ring->lock, isc_rwlocktype_read);
RWUNLOCK(&ring->lock, locktype);
adjust_lru(key);
*tsigkey = key;
return (ISC_R_SUCCESS);