PANIC: internal error when deleting users

[Michael Wood]

Hi

On 10 November 2010 17:26, Gianni L <slowsin at gmail.com> wrote:
> Hello,
> it's me again! maybe I have some good/strange news.
> I just took some time from work to compare the different entries from
> the ldifde exported files and I found that the entries that caused the
> crash have all a comma in the "dn", the "cn" and the
> "distinguishedName".

You should probably create a bug at https://bugzilla.samba.org/ with
all of the information from this thread so that it does not get
forgotten.

> for example an ldif entry containing the following:
>
> dn: CN=Name\, Surname,DC=my,DC=test,DC=domain
> cn: Name, Surname
> distinguishedName: CN=Name\, Surname,DC=my,DC=test,DC=domain
>
> will be imported fine, but makes the damon crash when trying to delete
> the entry.
>
> so most probably  ldb_dn_validate(dn) returns NULL when there is a
> "\," in the CN.
>
> hope this infos helps you now..
>
> greets
> Gianni
>
>
> On Tue, Nov 9, 2010 at 7:13 PM, Matthias Dieter Wallnöfer <mdw at samba.org> wrote:
>> The next step to check would be to find out where a DN with absolutely no
>> RDN value could be/was created. This place needs fixing.
>>
>> Greets,
>> Matthias
>>
>> Gianni L wrote:
>>>
>>> thanks Michael,
>>> doing a little check after calling ldb_dn_get_rdn_val() solves the
>>> crashing issue.
>>> but I still think I f*cked up my tdb files yesterday when I tried to
>>> delete the whole subtree from the directory.
>>> the "net ads user -S altair -U administrator" gives me the whole list
>>> of the users I imported yesterday.
>>> but not everyone of that users "exists" anymore in the db.
>>> fact is that if I try to delete a user where the information is still
>>> consistent in the directory it makes no problem but if I tried to
>>> delete another user the samba damon crashed.
>>> is there a way to repair the db files?
>>> if there's no way it's not a problem 'cause it's still a testserver :)
>>> thanks
>>> Gianni
>>>
>>> On Tue, Nov 9, 2010 at 3:48 PM, Michael Wood<esiotrot at gmail.com>  wrote:
>>>
>>>>
>>>> On 9 November 2010 15:11, Gianni L<slowsin at gmail.com>  wrote:
>>>>
>>>>>
>>>>> yeah! I think I finally got it :)
>>>>> here's now a more detailed backtrace of the crash..
>>>>> sorry for my inexperience with debugging tools :)
>>>>> hope the info helps a bit..
>>>>>
>>>>
>>>> OK, so val is NULL in ldb_msg_add_value().  It comes from this line
>>>> insource4/dsdb/samdb/ldb_modules/repl_meta_data.c:
>>>>
>>>> ret = ldb_msg_add_value(msg, strlower_talloc(tmp_ctx, rdn_name),
>>>> new_rdn_value,&el);
>>>>
>>>> i.e. new_rdn_value is NULL.
>>>>
>>>> new_rdn_value is set just above that:
>>>>
>>>>                /* work out what the new rdn value is, for updating the
>>>>                   rDN and name fields */
>>>>                new_rdn_value = ldb_dn_get_rdn_val(new_dn);
>>>>
>>>> and ldb_dn_get_rdn_val() does this:
>>>>
>>>> const struct ldb_val *ldb_dn_get_rdn_val(struct ldb_dn *dn)
>>>> {
>>>>        if ( ! ldb_dn_validate(dn)) {
>>>>                return NULL;
>>>>        }
>>>>        if (dn->comp_num == 0) return NULL;
>>>>        return&dn->components[0].value;
>>>> }
>>>>
>>>> So it seems there should be a check after calling ldb_dn_get_rdn_val()
>>>> to see if it returned NULL, or else the NULL value should be handled
>>>> in ldb_msg_add_value().
>>>>
>>>>
>>>>>
>>>>> On Tue, Nov 9, 2010 at 1:17 PM, Michael Wood<esiotrot at gmail.com>  wrote:
>>>>>
>>>>>
>>>>>>
>>>>>> Hi
>>>>>>
>>>>>> On 9 November 2010 13:29, Gianni L<slowsin at gmail.com>  wrote:
>>>>>>
>>>>>>>
>>>>>>> Hi Mat,
>>>>>>> sorry but I can't find any samba-segfault script, neither in the
>>>>>>> install
>>>>>>> location of samba 4 neither in the sourcecode :(
>>>>>>> tried even to search in the git sources of another computer and
>>>>>>> there's
>>>>>>> anything.
>>>>>>> if someone could provide me a copy of the script I would be happy to
>>>>>>> run
>>>>>>> another test and provide the results :)
>>>>>>>
>>>>>>
>>>>>> I don't have a samba-segfault script either, but try running "bt full"
>>>>>> in gdb when Samba crashes.  That will provide lots more useful
>>>>>> information.
>>>>>>
>>>>>> I've just found "examples/scripts/debugging/linux/backtrace" which
>>>>>> might be the script Matthieu is referring to.

-- 
Michael Wood <esiotrot at gmail.com>