diff --git a/backport-CVE-2023-2828.patch b/backport-CVE-2023-2828.patch new file mode 100644 index 0000000000000000000000000000000000000000..c00cb52f24877fab502542203aa53c08db653f14 --- /dev/null +++ b/backport-CVE-2023-2828.patch @@ -0,0 +1,171 @@ +From da0eafcdee52147e72d407cc3b9f179378ee1d3a Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= +Date: Tue, 30 May 2023 08:46:17 +0200 +Subject: [PATCH] Improve RBT overmem cache cleaning + +When cache memory usage is over the configured cache size (overmem) and +we are cleaning unused entries, it might not be enough to clean just two +entries if the entries to be expired are smaller than the newly added +rdata. This could be abused by an attacker to cause a remote Denial of +Service by possibly running out of the operating system memory. + +Currently, the addrdataset() tries to do a single TTL-based cleaning +considering the serve-stale TTL and then optionally moves to overmem +cleaning if we are in that condition. Then the overmem_purge() tries to +do another single TTL based cleaning from the TTL heap and then continue +with LRU-based cleaning up to 2 entries cleaned. + +Squash the TTL-cleaning mechanism into single call from addrdataset(), +but ignore the serve-stale TTL if we are currently overmem. + +Then instead of having a fixed number of entries to clean, pass the size +of newly added rdatasetheader to the overmem_purge() function and +cleanup at least the size of the newly added data. This prevents the +cache going over the configured memory limit (`max-cache-size`). + +Additionally, refactor the overmem_purge() function to reduce for-loop +nesting for readability + +--- + lib/dns/rbtdb.c | 93 ++++++++++++++++++++++++++++--------------------- + 1 file changed, 54 insertions(+), 39 deletions(-) + +diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c +index 6de89bb..6606769 100644 +--- a/lib/dns/rbtdb.c ++++ b/lib/dns/rbtdb.c +@@ -834,7 +834,7 @@ static void update_header(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, + static void expire_header(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, + bool tree_locked, expire_t reason); + static void overmem_purge(dns_rbtdb_t *rbtdb, unsigned int locknum_start, +- isc_stdtime_t now, bool tree_locked); ++ size_t purgesize, bool tree_locked); + static isc_result_t resign_insert(dns_rbtdb_t *rbtdb, int idx, + rdatasetheader_t *newheader); + static void resign_delete(dns_rbtdb_t *rbtdb, rbtdb_version_t *version, +@@ -6924,6 +6924,16 @@ addclosest(dns_rbtdb_t *rbtdb, rdatasetheader_t *newheader, + + static dns_dbmethods_t zone_methods; + ++static size_t ++rdataset_size(rdatasetheader_t *header) { ++ if (!NONEXISTENT(header)) { ++ return (dns_rdataslab_size((unsigned char *)header, ++ sizeof(*header))); ++ } ++ ++ return (sizeof(*header)); ++} ++ + static isc_result_t + addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, + isc_stdtime_t now, dns_rdataset_t *rdataset, unsigned int options, +@@ -7078,7 +7088,8 @@ addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version, + } + + if (cache_is_overmem) +- overmem_purge(rbtdb, rbtnode->locknum, now, tree_locked); ++ overmem_purge(rbtdb, rbtnode->locknum, rdataset_size(newheader), ++ tree_locked); + + NODE_LOCK(&rbtdb->node_locks[rbtnode->locknum].lock, + isc_rwlocktype_write); +@@ -10630,55 +10641,59 @@ update_header(dns_rbtdb_t *rbtdb, rdatasetheader_t *header, + ISC_LIST_PREPEND(rbtdb->rdatasets[header->node->locknum], header, link); + } + ++static size_t ++expire_lru_headers(dns_rbtdb_t *rbtdb, unsigned int locknum, size_t purgesize, ++ bool tree_locked) { ++ rdatasetheader_t *header, *header_prev; ++ size_t purged = 0; ++ ++ for (header = ISC_LIST_TAIL(rbtdb->rdatasets[locknum]); ++ header != NULL && purged <= purgesize; header = header_prev) ++ { ++ header_prev = ISC_LIST_PREV(header, link); ++ /* ++ * Unlink the entry at this point to avoid checking it ++ * again even if it's currently used someone else and ++ * cannot be purged at this moment. This entry won't be ++ * referenced any more (so unlinking is safe) since the ++ * TTL was reset to 0. ++ */ ++ ISC_LIST_UNLINK(rbtdb->rdatasets[locknum], header, link); ++ size_t header_size = rdataset_size(header); ++ expire_header(rbtdb, header, tree_locked, expire_lru); ++ purged += header_size; ++ } ++ ++ return (purged); ++} ++ + /*% +- * Purge some expired and/or stale (i.e. unused for some period) cache entries +- * under an overmem condition. To recover from this condition quickly, up to +- * 2 entries will be purged. This process is triggered while adding a new +- * entry, and we specifically avoid purging entries in the same LRU bucket as +- * the one to which the new entry will belong. Otherwise, we might purge +- * entries of the same name of different RR types while adding RRsets from a +- * single response (consider the case where we're adding A and AAAA glue records +- * of the same NS name). ++ * Purge some stale (i.e. unused for some period - LRU based cleaning) cache ++ * entries under the overmem condition. To recover from this condition quickly, ++ * we cleanup entries up to the size of newly added rdata (passed as purgesize). ++ * ++ * This process is triggered while adding a new entry, and we specifically avoid ++ * purging entries in the same LRU bucket as the one to which the new entry will ++ * belong. Otherwise, we might purge entries of the same name of different RR ++ * types while adding RRsets from a single response (consider the case where ++ * we're adding A and AAAA glue records of the same NS name). + */ + static void + overmem_purge(dns_rbtdb_t *rbtdb, unsigned int locknum_start, +- isc_stdtime_t now, bool tree_locked) ++ size_t purgesize, bool tree_locked) + { +- rdatasetheader_t *header, *header_prev; + unsigned int locknum; +- int purgecount = 2; ++ size_t purged = 0; + + for (locknum = (locknum_start + 1) % rbtdb->node_lock_count; +- locknum != locknum_start && purgecount > 0; ++ locknum != locknum_start && purged <= purgesize; + locknum = (locknum + 1) % rbtdb->node_lock_count) { + NODE_LOCK(&rbtdb->node_locks[locknum].lock, + isc_rwlocktype_write); + +- header = isc_heap_element(rbtdb->heaps[locknum], 1); +- if (header && header->rdh_ttl < now - RBTDB_VIRTUAL) { +- expire_header(rbtdb, header, tree_locked, +- expire_ttl); +- purgecount--; +- } +- +- for (header = ISC_LIST_TAIL(rbtdb->rdatasets[locknum]); +- header != NULL && purgecount > 0; +- header = header_prev) { +- header_prev = ISC_LIST_PREV(header, link); +- /* +- * Unlink the entry at this point to avoid checking it +- * again even if it's currently used someone else and +- * cannot be purged at this moment. This entry won't be +- * referenced any more (so unlinking is safe) since the +- * TTL was reset to 0. +- */ +- ISC_LIST_UNLINK(rbtdb->rdatasets[locknum], header, +- link); +- expire_header(rbtdb, header, tree_locked, +- expire_lru); +- purgecount--; +- } +- ++ purged += expire_lru_headers(rbtdb, locknum, purgesize - purged, ++ tree_locked); ++ + NODE_UNLOCK(&rbtdb->node_locks[locknum].lock, + isc_rwlocktype_write); + } +-- +2.27.0 diff --git a/bind.spec b/bind.spec index 47a11ff748219af5e7b3222f155a32bc5c3c6c66..b140b97c65353e6dfa606fca5aff652777f10d95 100644 --- a/bind.spec +++ b/bind.spec @@ -19,7 +19,7 @@ Name: bind Summary: Domain Name System (DNS) Server (named) License: MPLv2.0 Version: 9.11.21 -Release: 15 +Release: 16 Epoch: 32 Url: http://www.isc.org/products/BIND/ Source0: https://ftp.isc.org/isc/bind9/9.11.21/bind-%{version}.tar.gz @@ -242,6 +242,8 @@ Patch6066: backport-CVE-2022-2906.patch Patch6067: backport-CVE-2022-38177.patch Patch6068: backport-CVE-2022-38178.patch +Patch6069: backport-CVE-2023-2828.patch + %description Berkeley Internet Name Domain (BIND) is an implementation of the Domain Name System (DNS) protocols and provides an openly redistributable reference @@ -521,6 +523,7 @@ cp -a %{SOURCE29} lib/dns/tests/testdata/dstrandom/random.data %patch6066 -p1 %patch6067 -p1 %patch6068 -p1 +%patch6069 -p1 %patch199 -p1 @@ -1305,6 +1308,12 @@ rm -rf ${RPM_BUILD_ROOT} %changelog +* Mon Jun 26 2023 zhanghao - 32:9.11.21-16 +- Type:CVE +- ID:CVE-2023-2828 +- SUG:NA +- DESC:fix CVE-2023-2828 + * Mon Oct 10 2022 huangyu - 32:9.11.21-15 - Type:CVE - ID:CVE-2022-2906 CVE-2022-2881 CVE-2022-2795 CVE-2022-38178 CVE-2022-38177