[Samba] HELP: Samba server crashing on me

[John H Terpstra - Samba Team]

On 09/06/2009 10:47 PM, Timothy Normand Miller wrote:
> I'm stymied by the fact that no matter what I set the CFLAGS to in the
> environment, the compile is optimizing out symbols, but here's what
> I'm finding in the source:
> 
> static bool open_sockets_smbd(bool is_daemon, bool interactive, const
> char *smb_ports)
> {
> ...
>         struct dns_reg_state * dns_reg = NULL;
> 
> ... nothing that modifies dns_reg ...
> 
>                 /* process pending nDNS responses */
>                 if (dns_register_smbd_reply(dns_reg, &r_fds, &idle_timeout)) {
>                         --num;
>                 }
> ...
> }
> 
> 
> Then the function dns_register_smbd_reply blindly rereferences the
> first argument:
> 
> bool dns_register_smbd_reply(struct dns_reg_state *dns_state,
>                 fd_set *lfds, struct timeval *timeout)
> {
>         int mdnsd_conn_fd = -1;
> 
>         if (dns_state->srv_ref == NULL) {
>                 return false;
>         }
> ...
> }
> 
> So, can anyone tell me what I might do to avoid this sequence of
> events?  It didn't happen before.  I don't know what's causing it to
> happen now.
> 
> 
> On Sun, Sep 6, 2009 at 11:26 PM, Timothy Normand
> Miller<theosib at gmail.com> wrote:
>> This is where smbd is getting signal 11 (see the ***):
>>
>> /* Processes reply from mDNS daemon. Returns true if a reply was received */
>> bool dns_register_smbd_reply(struct dns_reg_state *dns_state,
>>                fd_set *lfds, struct timeval *timeout)
>> {
>>        int mdnsd_conn_fd = -1;
>>
>>        if (dns_state->srv_ref == NULL) {   // *** RIGHT HERE AT LINE 171 ***
>>                return false;
>>        }
>>
>>        mdnsd_conn_fd = DNSServiceRefSockFD(dns_state->srv_ref);
>>
>>        /* Process reply from daemon. Handles any errors. */
>>        if ((mdnsd_conn_fd != -1) && (FD_ISSET(mdnsd_conn_fd,lfds)) ) {
>>                DNSServiceErrorType err;
>>
>>                err = DNSServiceProcessResult(dns_state->srv_ref);
>>                if (err != kDNSServiceErr_NoError) {
>>                        DEBUG(3, ("failed to process mDNS result (err
>> %d), re-trying\n",
>>                                    err));
>>                        schedule_dns_register_smbd_retry(dns_state, timeout);
>>                }
>>
>>                return true;
>>        }
>>
>>        return false;
>> }
>>
>>
>> It appears that dns_state is null, which is evident from the stack trace:
>>
>> #6  dns_register_smbd_reply (dns_state=0x0, lfds=0x7fffbf342960,
>> timeout=0x7fffbf342af0) at smbd/dnsregister.c:171
>>
>> That's called from here in server.c, in main():
>>
>>                if (dns_register_smbd_reply(dns_reg, &r_fds, &idle_timeout)) {
>>                        --num;
>>                }
>>
>> Unfortunately, I can't debug further since dns_reg is optimized out by -O2.
>>
> 
> 
> 

Please file a bug report on https://bugzilla.samba.org - attach all the
info you presented on this list, and also the output of "testparm -s".

Suggest you also include the output of "smbd -b" and of "uname -a".

What is your platform?  Did you compile Samba yourself or is this from a
recognized packaged source?

Would like to understand why you have this problem and noone else has
reported this problem.

Cheers,
John T.