Described in: http://www.phrack.org/issues.html?issue=67&id=9#article
Reported by Stefan Cornelius / Red Hat Security Response Team
- convert internal positional arguments bookkeeping from int to size_t
- provide overflow protection in positional argument spec
- convert loops to memset
- fix memory leaks
- limit positional argument stack offset to the number of arguments required
by the printf to avoid coredump from va_arg() exhaustion.
If the current compiler doesn't support C99, check if it is compatible
with GCC 2.92. In that case, use the protected __restricted__ form.
In any other case, default to removing __restricted.
problem reported here but is part of the solution):
xen_kpm_sync() is not working as expected,
leading to races between CPUs.
1 the check (xpq_cpu != &x86_curcpu) is always false because we
have different x86_curcpu symbols with different addresses in the kernel.
Fortunably, all addresses dissaemble to the same code.
Because of this we always use the code intended for bootstrap, which doesn't
use cross-calls or lock.
2 once 1 above is fixed, xen_kpm_sync() will use xcalls to sync other CPUs,
which cause it to sleep and pmap.c doesn't like that. It triggers this
KASSERT() in pmap_unmap_ptes():
KASSERT(pmap->pm_ncsw == curlwp->l_ncsw);
3 pmap->pm_cpus is not safe for the purpose of xen_kpm_sync(), which
needs to know on which CPU a pmap is loaded *now*:
pmap->pm_cpus is cleared before cpu_load_pmap() is called to switch
to a new pmap, leaving a window where a pmap is still in a CPU's
ci_kpm_pdir but not in pm_cpus. As a virtual CPU may be preempted
by the hypervisor at any time, it can be large enough to let another
CPU free the PTP and reuse it as a normal page.
To fix 2), avoid cross-calls and IPIs completely, and instead
use a mutex to update all CPU's ci_kpm_pdir from the local CPU.
It's safe because we just need to update the table page, a tlbflush IPI will
happen later. As a side effect, we don't need a different code for bootstrap,
fixing 1). The mutex added to struct cpu needs a small headers reorganisation.
to fix 3), introduce a pm_xen_ptp_cpus which is updated from
cpu_pmap_load(), whith the ci_kpm_mtx mutex held. Checking it with
ci_kpm_mtx held will avoid overwriting the wrong pmap's ci_kpm_pdir.
While there I removed the unused pmap_is_active() function;
and added some more details to DIAGNOSTIC panics.
- to reduce cpu consumption for a long queue, maintain the sorted lists of
buffers with rbtree instead of TAILQ. i vaguely remember that the problem
pointed out by someone on a public mailing list while ago. sorry, i can't
remember who and where.
- add some #ifdef'ed out experimental code.
- bump kernel version for struct buf change.
- The Postfix sqlite client, introduced with Postfix 2.8, had an
embarassing bug in its quoting routine. As the result of a
last-minute code cleanup before release, this routine returned the
unquoted text instead of the quoted text. The opportunities for
mis-use are limited: Postfix sqlite database files are usually owned
by root, and Postfix daemons usually run with non-root privileges so
they can't corrupt the database. This problem was reported by Rob
McGee (rob0).
- The Postfix 2.8.4 fix for local delivery agent database lookup
errors was incomplete. The fix correctly added new code to detect
database lookup errors with mailbox_transport_maps,
mailbox_command_maps or fallback_transport_maps, but it failed to
log the problem, and to produce a defer logfile record which is
needed for "delayed mail" and "mail too old" delivery status
notifications.
- The trace(8) service, used for DSN SUCCESS notifications, did not
distinguish between notifications for a non-bounce or a bounce
message, causing it to "reply" to mail with the null sender
address. Problem reported by Sabahattin Gucukoglu.
- Support for Dovecot auth over TCP sockets, using code that already
existed for testing purposes. Patrick Koetter kindly provided an
update for the SASL_README file.
- Workaround in the LDAP client for changes in the under-documented
OpenLDAP API, by Victor Duchovni.
vector. This can normally be found via __ps_strings, but libc is
initialised too early when linked dynamically and doesn't have access to
it yet, so provide an alternative mechanism via ld.elf_so.
Bump libc minor.
