[mrtdump branch] Segfault when using a long filename for mrtdump

[Pavel Tvrdík]

Hi Baptiste!

On 2016-04-26 16:46, Baptiste Jonglez wrote:
> Hi,
> 
> I have been experimenting with the mrtdump branch (commit cc4eee62) on
> Debian jessie.

Thank you for testing experimental code from GIT!

> 
> However, when using a moderately long filename, Bird crashes.
> For instance:
> 
>     birdc6 'mrtdump routes to "/bird/mrtdump/rib.ipv6.20160426.1209"'
>     BIRD 1.5.0 ready.
>     Connection closed by server.
> 
> The logs are the following:
> 
>     bird6[8314]: Unable to open file "<too-long>" for MRT dump of table 
> master
>     systemd[1]: bird6.service: main process exited, code=killed, 
> status=11/SEGV
>     systemd[1]: Unit bird6.service entered failed state.
>     kernel: bird6[8314]: segfault at 18 ip 00007fb05162a905 sp
> 00007ffe1194f5a0 error 4 in bird6[7fb051602000+76000]
> 
> It looks like TM_DATETIME_BUFFER_SIZE, as used in tm_format_datetime(), 
> is
> really too small (32 bytes).  Also, there seems to be an issue with 
> error
> handling (segfault when tm_format_datetime returns unexpected data).
> 
> When defining a higher value for TM_DATETIME_BUFFER_SIZE, bird does not
> crash anymore, but there is certainly a better solution.

Yes, exactly. I'll send a patch tomorrow!

> Thanks,
> Baptiste