If a node cleaned up by prune_tree() happens to belong to the same node
bucket as its parent, the latter is directly appended to the prunenodes
list currently processed by prune_tree(). However, the relevant code
branch does not account for the fact that the parent might already be on
the list it is trying to append it to. Fix by only calling
ISC_LIST_APPEND() for parent nodes not yet added to their relevant
prunenodes list.
(cherry picked from commit 4b6fc97af6)
Commit 801e888d03 made the prune_tree()
function use send_to_prune_tree() for triggering pruning of deleted leaf
nodes' parents. This enabled the following sequence of events to
happen:
1. Node A, which is a leaf node, is passed to send_to_prune_tree() and
its pruning is queued.
2. Node B is added to the RBTDB as a child of node A before the latter
gets pruned.
3. Node B, which is now a leaf node itself (and is likely to belong to
a different node bucket than node A), is passed to
send_to_prune_tree() and its pruning gets queued.
4. Node B gets pruned. Its parent, node A, now becomes a leaf again
and therefore the prune_tree() call that handled node B calls
send_to_prune_tree() for node A.
5. Since node A was already queued for pruning in step 1 (but not yet
pruned), the INSIST(!ISC_LINK_LINKED(node, prunelink)); assertion
fails for node A in send_to_prune_tree().
The above sequence of events is not a sign of pathological behavior.
Replace the assertion check with a conditional early return from
send_to_prune_tree().
(cherry picked from commit f6289ad931)
It was discovered that the TTL-based cleaning could build up
a significant backlog of the rdataset headers during the periods where
the top of the TTL heap isn't expired yet. Make the TTL-based cleaning
more aggressive by cleaning more headers from the heap when we are
adding new header into the RBTDB.
(cherry picked from commit d8220ca4ca)
(cherry picked from commit 496fe6bc60)
It was discovered that an expired header could sit on top of the heap
a little longer than desireable. Remove expired headers (headers with
rdh_ttl set to 0) from the heap completely, so they don't block the next
TTL-based cleaning.
(cherry picked from commit a9383e4b95)
(cherry picked from commit abe080d16e)
The log message for commit c3377cbfaa
explained:
Instead of issuing a separate isc_task_send() call for every RBTDB node
that triggers tree pruning, maintain a list of nodes from which tree
pruning can be started from and only issue an isc_task_send() call if
pruning has not yet been triggered by another RBTDB node.
The extra queuing overhead eliminated by this change could be remotely
exploited to cause excessive memory use.
However, it turned out that having a single queue for the nodes to be
pruned increased lock contention to a level where cleaning up nodes from
the RBTDB took too long, causing the amount of memory used by the cache
to grow indefinitely over time.
This commit makes the prunenodes list bucketed, adds a quantum of 10
items per prune_tree() run, and simplifies parent node cleaning in the
prune_tree() logic.
Instead of juggling node locks in a cycle, only clean up the node
currently being pruned and queue its parent (if it is also eligible) for
pruning in the same way (by sending an event).
This simplifies the code and also spreads the pruning load across more
task loop ticks, which is better for lock contention as less things run
in a tight loop.
(cherry picked from commit 2df147cb12)
dns__cacherbt_expireheader can unlink / free header_prev underneath
it. Use ISC_LIST_TAIL after calling dns__cacherbt_expireheader
instead to get the next pointer to be processed.
(cherry picked from commit 7ce2e86024)
Don't parse the crypto data before parsing and matching the id and the
algorithm for consecutive DNSKEYs. This allows us to parse the RData
only in case the other parameters match allowing us to skip keys that
are of no interest to us, but still would consume precious CPU time by
parsing possibly garbage with OpenSSL.
(cherry picked from commit f39cd17a26)
Remember the position in the iterator when selecting the next signing
key. This should speed up processing for larger DNSKEY RRSets because
we don't have to iterate from start over and over again.
(cherry picked from commit 21af5c9a97)
Change the taskmgr (and thus netmgr) in a way that it supports fast and
slow task queues. The fast queue is used for incoming DNS traffic and
it will pass the processing to the slow queue for sending outgoing DNS
messages and processing resolver messages.
In the future, more tasks might get moved to the slow queues, so the
cached and authoritative DNS traffic can be handled without being slowed
down by operations that take longer time to process.
(cherry picked from commit 1b3b0cef22)
The fix for CVE-2023-4408 introduced a regression in the message
parser, which could cause a crash if an rdata type that can only
occur in the question was found in another section.
(cherry picked from commit 510f1de8a6)
the fix for CVE-2023-4408 introduced a regression in the message
parser, which could cause a crash if duplicate rdatasets were found
in the question section. this commit ensures that rdatasets are
correctly disassociated and freed when this occurs.
(cherry picked from commit 4c19d35614)
Instead of issuing a separate isc_task_send() call for every RBTDB node
that triggers tree pruning, maintain a list of nodes from which tree
pruning can be started from and only issue an isc_task_send() call if
pruning has not yet been triggered by another RBTDB node.
The extra queuing overhead eliminated by this change could be remotely
exploited to cause excessive memory use.
As this change modifies struct dns_rbtnode by adding a new 'prunelink'
member to it, bump MAPAPI to prevent any attempts of loading map-format
zone files created using older BIND 9 versions.
(cherry picked from commit 24381cc36d)
To prevent allocating large hashtable in dns_message, we need to
backport the improvements to isc_ht API from BIND 9.18+ that includes
support for case insensitive keys and incremental rehashing of the
hashtables.
When parsing messages use a hashtable instead of a linear search to
reduce the amount of work done in findname when there's more than one
name in the section.
There are two hashtables:
1) hashtable for owner names - that's constructed for each section when
we hit the second name in the section and destroyed right after parsing
that section;
2) per-name hashtable - for each name in the section, we construct a new
hashtable for that name if there are more than one rdataset for that
particular name.
(cherry picked from commit b8a9631754)
When kasp support was added 'inception' was used as a proxy for
'now' and resulted in signatures not being generated or the wrong
signatures being generated. 'inception' is the time to be set
in the signatures being generated and is usually in the past to
allow for clock skew. 'now' determines what keys are to be used
for signing.
(cherry picked from commit 6066e41948)
The maximum DNS message size is 65535 octets. Check that the buffer
being passed to dns_message_renderbegin does not exceed this as the
compression code assumes that all offsets are no bigger than this.
(cherry picked from commit a069513234)
when transferring in a non-inline-signing secondary for the first time,
we previously never set the value of zone->loadtime, so it remained
zero. this caused a test failure in the statschannel system test,
and that test case was temporarily disabled. the value is now set
correctly and the test case has been reinstated.
(cherry picked from commit 9643281453)
To reduce the amount of log spam when root servers change their
addresses keep a table of upcoming changes by expected date and time
and suppress reporting differences for them until then.
Add initial entry for B.ROOT-SERVERS.NET, Nov 27, 2023.
(cherry picked from commit b69100b747)
This covers both root hints and the default primaries for the root
zone mirror. The official change date is Nov 27, 2023.
(cherry picked from commit 2ca2f7e985)
Move the declaration of 'engine' within the appropriate #if/#endif
block. Remove the UNUSED(engine) from the #else block.
(cherry picked from commit 8b11061b91)
Apply the semantic patch to catch all the places where we pass 'char' to
the <ctype.h> family of functions (isalpha() and friends, toupper(),
tolower()).
(cherry picked from commit 29caa6d1f0)
Add a unit test to check if the overmem purging in the RBTDB is
effective when mixed size RR data is inserted into the database.
Co-authored-by: Ondřej Surý <ondrej@isc.org>
Co-authored-by: Jinmei Tatuya <jtatuya@infoblox.com>
(manually picked from 269c03831f)
When a primary server is not responding, mark it as temporarialy
unreachable. This will prevent too many zones queuing up on a
unreachable server and allow the refresh process to move onto
the next primary sooner once it has been so marked.
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.
The zone_resigninc() function does not check the validity of
'zone->db', which can crash named if the zone was unloaded earlier,
for example with "rndc delete".
Check that 'zone->db' is not 'NULL' before attaching to it, like
it is done in zone_sign() and zone_nsec3chain() functions, which
can similarly be called by zone maintenance.
(cherry picked from commit fae0930eb8)
deserialize_corrupt_test may corrupt the pointers such that they
is no longer properly aligned. Check that the alignment is consistent
with memory returned from isc_mem before checking the magic value.
When OPTOUT was in use we didn't ensure that NSEC3 records
for orphaned empty-non-terminals where removed. Check if
there are orphaned empty-non-terminal NSEC3 even if there
wasn't an NSEC3 RRset to be removed in dns_nsec3_delnsec3.
(cherry picked from commit 27160c137f)
dns_rdata_fromstruct in dns_keytable_deletekey can potentially
fail with ISC_R_NOSPACE. Handle the error condition.
(cherry picked from commit b5df9b8591)
In selfsigned_dnskey only call dns_dnssec_verify if the signature's
key id matches a revoked key, the trust is pending and the key
matches a trust anchor. Previously named was calling dns_dnssec_verify
unconditionally resulted in busy work.
(cherry picked from commit e68fecbdaa)
If the zone already has existing NSEC/NSEC3 chains then zone_sign
needs to continue to use them. If there are no chains then use
kasp setting otherwise generate an NSEC chain.
(cherry picked from commit 4b55201459)
This reverts commit 1254f37584.
The commit introduced a data race, because dns_db_endload() is called
after unfreezing the zone.
(not cherry picked from commit 593dea871a)
When detaching from the previous version of the database, make sure
that the update-notify callback is unregistered, otherwise there is
an INSIST check which can generate an assertion failure in free_rbtdb(),
which checks that there are no outstanding update listeners in the list.
There is a similar code already in place for RPZ.
(cherry picked from commit cf79692a66)
The zone_postload() function can fail and unregister the callbacks.
Call dns_db_endload() only after calling zone_postload() to make
sure that the registered update-notify callbacks are not called
when the zone loading has failed during zone_postload().
Also, don't ignore the return value of zone_postload().
(cherry picked from commit ed268b46f1)
Michał Kępień
Ondřej Surý
Mark AndrewsandOndřej Surý
Michal NowakandMichał Kępień
Evan HuntandMichał Kępień
Matthijs MekkingandMichał Kępień
Aram Sargsyan
Petr Špaček