[Freeipa-devel] [PATCH 0257] Fix race condition during zone loading

[Petr Spacek]

On 28.5.2014 13:26, Tomas Hozza wrote:
> On 05/27/2014 03:59 PM, Petr Spacek wrote:
>> On 27.5.2014 15:54, Petr Spacek wrote:
>>> Fix race condition during zone loading.
>>>
>>> DNS zone has to be added to DNS view before dns_zone_load() is called.
>>> It is necessary to prevent dns_zone_load() from racing with
>>> dns_zone_setview().
>>>
>>> This race condition sometimes prevents zone from being signed.
>>> Now the unsigned zone is visible until signing process is complete. This
>>> mimics BIND behavior for in-line signed zones.
>>>
>>> https://fedorahosted.org/bind-dyndb-ldap/ticket/56
>>
>> And here is the patch...
>>
>
> Hi.
>
> When I use bind-dyndb-ldap plugin with this patch, named
> does not start due to:
>
> rbt.c:1379: REQUIRE(name->buffer != ((void *)0)) failed, back trace
>
> (gdb) bt
> #0  0x00007f3963924c39 in raise () from /lib64/libc.so.6
> #1  0x00007f3963926348 in abort () from /lib64/libc.so.6
> #2  0x00007f3966979aee in assertion_failed ()
> #3  0x00007f3964b6917a in isc_assertion_failed () from /lib64/libisc.so.95
> #4  0x00007f39661ca9da in dns_rbt_fullnamefromnode () from
> /lib64/libdns.so.100
> #5  0x00007f396011824b in rbt_iter_getnodename (iter=<optimized out>,
> nodename=nodename at entry=0x7f39625f8bf0) at rbt_helper.c:46
> #6  0x00007f396011839b in rbt_iter_next
> (iterp=iterp at entry=0x7f39625f8b90,
> nodename=nodename at entry=0x7f39625f8bf0) at rbt_helper.c:144
> #7  0x00007f3960112d32 in activate_zones
> (task=task at entry=0x7f39668f5790, inst=0x7f39668e4160) at ldap_helper.c:1164
> #8  0x00007f396011a20d in barrier_decrement (task=0x7f39668f5790,
> event=0x7f396005b010) at syncrepl.c:138
> #9  0x00007f3964b8b836 in run () from /lib64/libisc.so.95
> #10 0x00007f396473ff33 in start_thread () from /lib64/libpthread.so.0
> #11 0x00007f39639e3ded in clone () from /lib64/libc.so.6
>
>
> It looks like you should use INIT_BUFFERED_NAME(name); used in the
> original code instead of dns_name_init(&name, NULL). The macro
> initializes the buffer in "name", which is missing in the new code.

Oh yes, it didn't happened on my machine because I have had only single zone 
defined in LDAP at the time of testing. Thank you for catching this!

I'm attaching fixed patch. dns_name_reset() is good enough in this case.

-- 
Petr^2 Spacek
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