[CVE-2021-25215] [v9_11] Properly answer queries for DNAME records that require the DNAME to be processed to resolve itself
See merge request isc-private/bind9!282
When answering a query, named should never attempt to add the same RRset
to the ANSWER section more than once. However, such a situation may
arise when chasing DNAME records: one of the DNAME records placed in the
ANSWER section may turn out to be the final answer to a client query,
but there is no way to know that in advance. Tweak the relevant INSIST
assertion in query_find() so that it handles this case properly. The
rdataset is freed later anyway, so there is no need to clean it up
immediately.
If a zone transfer results in a zone not having any NS records, named
stops serving it because such a zone is broken. Do the same if an
incoming zone transfer results in a zone lacking an SOA record at the
apex or containing more than one SOA record.
An IXFR containing SOA records with owner names different than the
transferred zone's origin can result in named serving a version of that
zone without an SOA record at the apex. This causes a RUNTIME_CHECK
assertion failure the next time such a zone is refreshed. Fix by
immediately rejecting a zone transfer (either an incremental or
non-incremental one) upon detecting an SOA record not placed at the apex
of the transferred zone.
GitLab CI pipelines do not currently include a Linux job that would have
GSSAPI support disabled. Add the "--without-gssapi" option to the
./configure invocation on Debian 9 to address that deficiency and also
to continuously test that build-time switch.
(cherry picked from commit a3957af864)
If "tkey-gssapi-credential" is set in the configuration and GSSAPI
support is not available, named will refuse to start. As the test
system framework does not support starting named instances
conditionally, ensure that "tkey-gssapi-credential" is only present in
named.conf if GSSAPI support is available.
(cherry picked from commit 6feac68b50)
Four named instances in the "nsupdate" system test have GSS-TSIG support
enabled. All of them currently use "tkey-gssapi-keytab". Configure two
of them with "tkey-gssapi-credential" to test that option.
As "tkey-gssapi-keytab" and "tkey-gssapi-credential" both provide the
same functionality, no test modifications are required. The difference
between the two options is that the value of "tkey-gssapi-keytab" is an
explicit path to the keytab file to acquire credentials from, while the
value of "tkey-gssapi-credential" is the name of the principal whose
credentials should be used; those credentials are looked up in the
keytab file expected by the Kerberos library, i.e. /etc/krb5.keytab by
default. The path to the default keytab file can be overridden using by
setting the KRB5_KTNAME environment variable. Utilize that variable to
use existing keytab files with the "tkey-gssapi-credential" option.
The KRB5_KTNAME environment variable should not interfere with the
"tkey-gssapi-keytab" option. Nevertheless, rename one of the keytab
files used with "tkey-gssapi-keytab" to something else than the contents
of the KRB5_KTNAME environment variable in order to make sure that both
"tkey-gssapi-keytab" and "tkey-gssapi-credential" are actually tested.
(cherry picked from commit 1746d2e84a)
BIND 9 attempts to look up GSSAPI OIDs for the Kerberos 5 and SPNEGO
mechanisms in the relevant header files provided by the Kerberos/GSSAPI
library used. Due to the differences between various Kerberos/GSSAPI
implementations, if any of the expected preprocessor macros
(GSS_KRB5_MECHANISM, GSS_SPNEGO_MECHANISM) is not defined in the header
files provided by the library used, the code in lib/dns/gssapictx.c
defines its own version of each missing macro, so that BIND 9 can
attempt to use the relevant security mechanisms anyway.
Commit 7f08c756aa, which contains a
partial backport of the changes introduced in commit
978c7b2e89, left a block of code in the
lib/dns/include/dst/gssapi.h header which defines the
GSS_SPNEGO_MECHANISM preprocessor macro to NULL if it is not defined by
any header file provided by the Kerberos/GSSAPI library used. This
causes the gss_add_oid_set_member() call in the mech_oid_set_create()
helper function to always return an error. This in turn causes the
dst_gssapi_acquirecred() function to also always return an error, which
ultimately prevents any named instance whose configuration includes the
"tkey-gssapi-credential" option from starting.
Remove the offending conditional definition of the GSS_SPNEGO_MECHANISM
preprocessor macro from lib/dns/include/dst/gssapi.h, so that a proper
GSSAPI OID is assigned to that macro in lib/dns/gssapictx.c when the
Kerberos/GSSAPI library used does not define it.
(cherry picked from commit 648ef3a2b4)
Commit 7f08c756aa inadvertently included
libtool updates which were unrelated to the removal of custom SPNEGO
code. Roll these updates back to avoid confusion.
(cherry picked from commit 87f1db2ce4)
add matching macros to pass arguments from called methods
to generic methods. This will reduce the amount of work
required when extending methods.
Also cleanup unnecessary UNUSED declarations.
(cherry picked from commit a88d3963e2)
Even if a call to gss_accept_sec_context() fails, it might still cause a
GSS-API response token to be allocated and left for the caller to
release. Make sure the token is released before an early return from
dst_gssapi_acceptctx().
(cherry picked from commit d954e152d9)
Commit de35d321f0 (a backport of commit
4d5d3b75da) did not account for the fact
that the "tarball-create" GitLab CI job is not created for manually
triggered pipelines. This prevents manual pipeline creation from
succeeding as it causes the "gcc:tarball" job to have unsatisfied
dependencies. Make sure the "tarball-create" job is created for
manually triggered pipelines to allow such pipelines to be started
again.
(cherry picked from commit 233294d750)
Fix race between zone_maintenance and dns_zone_notifyreceive functions,
zone_maintenance was attempting to read a zone flag calling
DNS_ZONE_FLAG(zone, flag) while dns_zone_notifyreceive was updating
a flag in the same zone calling DNS_ZONE_SETFLAG(zone, ...).
The code reading the flag in zone_maintenance was not protected by the
zone's lock, to avoid a race the zone's lock is now being acquired
before an attempt to read the zone flag is made.
Previously, every function had it's own #ifdef GSSAPI #else #endif block
that defined shim function in case GSSAPI was not being used. Now the
dummy shim functions have be split out into a single #else #endif block
at the end of the file.
This makes the gssapictx.c similar to 9.17.x code, making the backports
and reviews easier.
The Heimdal Kerberos library handles the OID sets in a different manner.
Unify the handling of the OID sets between MIT and Heimdal
implementations by dynamically creating the OID sets instead of using
static predefined set. This is how upstream recommends to handle the
OID sets.
The custom ISC SPNEGO mechanism implementation is no longer needed on
the basis that all major Kerberos 5/GSSAPI (mit-krb5, heimdal and
Windows) implementations support SPNEGO mechanism since 2006.
This commit removes the custom ISC SPNEGO implementation, and removes
the option from both autoconf and win32 Configure script. Unknown
options are being ignored, so this doesn't require any special handling.
When the authsock.pl script would be terminated with a signal,
it would leave the pidfile around. This commit adds a signal
handler that cleanups the pidfile on signals that are expected.
The gcc:tarball CI job may identify problems with tarballs created by
"make dist" of the tarball-create CI job. Enabling the gcc:tarball CI
job in web-triggered pipelines provides developers with a test vector.
(cherry picked from commit 4d5d3b75da)
Michał Kępień
Tinderbox UserandMichał Kępień
Mark AndrewsandMichał Kępień
Petr Špaček
Diego dos Santos Fronza
Ondřej Surý
Michal Nowak