1549 cleanup:
1550 if (dctx->dbiter != NULL)
1551 dns_dbiterator_destroy(&dctx->dbiter);
1552 if (dctx->db != NULL)
1553 dns_db_detach(&dctx->db);
CID 1452686 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking dctx suggests that it may
be null, but it has already been dereferenced on all paths
leading to the check.
1554 if (dctx != NULL)
1555 isc_mem_put(mctx, dctx, sizeof(*dctx));
389 else
CID 1452695 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking lcfg suggests that it may
be null, but it has already been dereferenced on all paths
leading to the check.
390 if (lcfg != NULL)
391 isc_logconfig_destroy(&lcfg);
6412 cleanup:
6413 dns_rdataset_disassociate(&neg);
6414 dns_rdataset_disassociate(&negsig);
CID 1452700 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking closest suggests that it
may be null, but it has already been dereferenced on all
paths leading to the check.
6415 if (closest != NULL)
6416 free_noqname(mctx, &closest);
13429 cleanup:
13430 cancel_refresh(zone);
CID 1452702 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking stub suggests that it may
be null, but it has already been dereferenced on all paths
leading to the check.
13431 if (stub != NULL) {
13432 stub->magic = 0;
6367cleanup:
6368 dns_rdataset_disassociate(&neg);
6369 dns_rdataset_disassociate(&negsig);
CID 1452704 (#1 of 1): Dereference before null check
(REVERSE_INULL) check_after_deref: Null-checking noqname
suggests that it may be null, but it has already been
dereferenced on all paths leading to the check.
6370 if (noqname != NULL)
6371 free_noqname(mctx, &noqname);
1401 }
CID 1453455 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking event suggests that it may be null,
but it has already been dereferenced on all paths leading to the check.
1402 if (event != NULL)
1403 isc_event_free(ISC_EVENT_PTR(&event));
128 return (ISC_R_SUCCESS);
129
CID 1456146 (#1 of 1): Structurally dead code (UNREACHABLE)
unreachable: This code cannot be reached: {
if (dst->labels[i] != N....
130 do {
402 ctx->serve_stale_ttl = 0;
notnull: At condition indentctx, the value of indentctx
cannot be NULL. dead_error_condition: The condition indentctx
must be true.
CID 1456147 (#1 of 1): Logically dead code (DEADCODE)
dead_error_line: Execution cannot reach the expression
default_indent inside this statement: ctx->indent = (indentctx
? ....
403 ctx->indent = indentctx ? *indentctx : default_indent;
1636 cleanup:
CID 1458130 (#1 of 1): Dereference before null check (REVERSE_INULL)
check_after_deref: Null-checking buffer suggests that it may be
null, but it has already been dereferenced on all paths leading to
the check.
1637 if (buffer != NULL)
1638 isc_buffer_free(&buffer);
Found by LGTM.com (see below for description), and while it should not
happen as EDNS OPT RDLEN is uint16_t, the fix is easy. A little bit
of cleanup is included too.
> In a loop condition, comparison of a value of a narrow type with a value
> of a wide type may result in unexpected behavior if the wider value is
> sufficiently large (or small). This is because the narrower value may
> overflow. This can lead to an infinite loop.
This commit simplifies the cachedb rrset statistics in two ways:
- Introduce new rdtypecounter arithmetics, allowing bitwise
operations.
- Remove the special DLV statistic counter.
New rdtypecounter arithmetics
-----------------------------
"The rdtypecounter arithmetics is a brain twister". Replace the
enum counters with some defines. A rdtypecounter is now 8 bits for
RRtypes and 3 bits for flags:
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
| | | | | | S |NX| RRType |
+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
If the 8 bits for RRtype are all zero, this is an Other RRtype.
Bit 7 is the NXRRSET (NX) flag and indicates whether this is a
positive (0) or a negative (1) RRset.
Then bit 5 and 6 mostly tell you if this counter is for an active,
stale, or ancient RRtype:
S = 0x00 means Active
S = 0x01 means Stale
S = 0x10 means Ancient
Since a counter cannot be stale and ancient at the same time, we
treat S = 0x11 as a special case to deal with NXDOMAIN counters.
S = 0x11 indicates an NXDOMAIN counter and in this case the RRtype
field signals the expiry of this cached item:
RRType = 0 means Active
RRType = 1 means Stale
RRType = 2 means Ancient
This also removes counting the DLV RRtype separately. Since we have
deprecated the lookaside validation it makes no sense to keep this
special statistic counter.
- Add quotes before and after zone name when generating "addzone"
input so avoid "unexpected token" errors.
- Use a hex digest for zone filenames when the zone or view name
contains a slash.
- Test with a domain name containing a slash.
- Incidentally added 'catzhash.py' to contrib/scripts to generate
hash labels for catalog zones, as it was needed to write the test.
The isc_buffer_allocate() function now cannot fail with ISC_R_MEMORY.
This commit removes all the checks on the return code using the semantic
patch from previous commit, as isc_buffer_allocate() now returns void.
The isc_mempool_create() function now cannot fail with ISC_R_MEMORY.
This commit removes all the checks on the return code using the semantic
patch from previous commit, as isc_mempool_create() now returns void.
The `rndc signing -clear` command cleans up the private-type records
that keep track of zone signing activity, but before this change it
did not tell the secondary servers that the zone has changed.
Function dns_view_findzonecut in view.c wasn't correctly handling
classes other than IN (chaos, hesiod, etc) whenever the name being
looked up wasn't in cache or in any of the configured zone views' database.
That resulted in a NULL fname being used in resolver.c:4900, which
in turn was triggering abort.
If we created a key, mark its SyncPublish time as 'now' and started
bind the key might not be published if the SyncPublish time is in
the same second as the time the zone is loaded. This is mostly
for dnssec system test, as this kind of scenario is very unlikely
in a real world environment.
To reproduce the race - create a task, send two events to it, first one
must take some time. Then, from the outside, pause(), unpause() and detach()
the task.
When the long-running event is processed by the task it is in
task_state_running state. When we called pause() the state changed to
task_state_paused, on unpause we checked that there are events in the task
queue, changed the state to task_state_ready and enqueued the task on the
workers readyq. We then detach the task.
The dispatch() is done with processing the event, it processes the second
event in the queue, and then shuts down the task and frees it (as it's not
referenced anymore). Dispatcher then takes the, already freed, task from
the queue where it was wrongly put, causing an use-after free and,
subsequently, either an assertion failure or a segmentation fault.
The probability of this happening is very slim, yet it might happen under a
very high load, more probably on a recursive resolver than on an
authoritative.
The fix introduces a new 'task_state_pausing' state - to which tasks
are moved if they're being paused while still running. They are moved
to task_state_paused state when dispatcher is done with them, and
if we unpause a task in paused state it's moved back to task_state_running
and not requeued.
This is a bug I encountered when trying to schedule an algorithm
rollover. My plan, for a zone whose maximum TTL is 48h, was to sign
with the new algorithm and schedule a change of CDS records for more
than 48 hours in the future, roughly like this:
$ dnssec-keygen -a 13 -fk -Psync now+50h $zone
$ dnssec-keygen -a 13 $zone
$ dnssec-settime -Dsync now+50h $zone_ksk_old
However the algorithm 13 CDS was published immediately, which could
have made the zone bogus.
To reveal the bug using the `smartsign` test, this change just adds a
KSK with all its times in the future, so it should not affect the
existing checks at all. But the final check (that there are no CDS or
CDSNSKEY records after -Dsync) fails with the old `syncpublish()`
logic, because the future key's sync records appear early. With the
new `syncpublish()` logic the future key does not affect the test, as
expected, and it now passes.
When two threads unreferenced handles coming from one socket while
the socket was being destructed we could get a use-after-free:
Having handle H1 coming from socket S1, H2 coming from socket S2,
S0 being a parent socket to S1 and S2:
Thread A Thread B
Unref handle H1 Unref handle H2
Remove H1 from S1 active handles Remove H2 from S2 active handles
nmsocket_maybe_destroy(S1) nmsocket_maybe_destroy(S2)
nmsocket_maybe_destroy(S0) nmsocket_maybe_destroy(S0)
LOCK(S0->lock)
Go through all children, figure
out that we have no more active
handles:
sum of S0->children[i]->ah == 0
UNLOCK(S0->lock)
destroy(S0)
LOCK(S0->lock)
- but S0 is already gone
