Re: [pptp-devel] Segfault in pptpcm

[James C. <qu...@la...>]

On Tue, Apr 14, 2015 at 11:34:59AM +0200, Lorenzo Maurizi - C.S.I.A. UniMC wrote:
> Dear all,
> I'm new here and I've just signed up to the mailing list to report a problem
> I am facing with pptpclient.
> 
> My setup is debian 7 Wheezy with pptp-linux package installed (1.7.2-7
> version)
> The ppp package installed for dependency is 2.4.5-5.1+deb7u1
> The counterpart of the connection is a Windows Server 2012 R2 with a simple
> incoming connection enabled (not RRAS). The connection from another windows
> 8.1 client is working without problems.
> 
> The problem is that connection drops after one minute and a half for a
> segfault in pptpcm module. As I made the connection persistent, the tunnel
> restores, but with the same error after the same amount of time.
> Moreover, in that 1.5 minutes window, I can't route any traffic inside the
> tunnel, despite I put a rule creating the route upon connection.
> 
> Here is the relevant part of the /var/log/messages file:
> 
> Apr 14 11:26:47 oldportal2 pppd[62659]: Using interface ppp0
> Apr 14 11:26:47 oldportal2 pppd[62659]: Connect: ppp0 <--> /dev/pts/2
> Apr 14 11:26:49 oldportal2 pppd[62659]: CHAP authentication succeeded
> Apr 14 11:26:49 oldportal2 pppd[62659]: MPPE 128-bit stateless compression
> enabled
> Apr 14 11:26:51 oldportal2 pppd[62659]: local  IP address 192.168.0.112
> Apr 14 11:26:51 oldportal2 pppd[62659]: remote IP address 172.16.0.10
> Apr 14 11:28:31 oldportal2 pppd[62659]: Modem hangup

This hangup is the critical issue.  Please enable debug logging and
give us another log to look at.

http://pptpclient.sourceforge.net/howto-diagnosis.phtml#debug

> Apr 14 11:28:31 oldportal2 kernel: [412887.322010] pptpcm[62669]: segfault
> at 7ffc9d9a42d0 ip 0000000000405634 sp 00007ffc9d645390 error 4 in
> pptp[400000+10000]

This is incidental, and probably fixed by patch "vector: remove
clobbered heap" ca29b846ccb924df388a1d396a25325c32b2e346, please check
that it has been applied.

Debian 1.7.2-7 doesn't include it.

> Apr 14 11:28:31 oldportal2 pppd[62659]: Connect time 1.7 minutes.
> Apr 14 11:28:31 oldportal2 pppd[62659]: Sent 0 bytes, received 0 bytes.
> Apr 14 11:28:31 oldportal2 pppd[62659]: Connection terminated.
> 
> This block of lines is then repeated until I "poff" the pptp connection.
> 
> What can I do to obtain correct operation of the PPTP tunnel?
> Thanks in advance.
> 
> Lorenzo

-- 
James Cameron
http://quozl.linux.org.au/