Bug 1805

Summary:

consumption of file descriptors using a port forwarding channel

Product:

Portable OpenSSH

Reporter:

Walter.Pfannenmueller

Component:

sshd

Assignee:

Assigned to nobody <unassigned-bugs>

Status:

CLOSED WORKSFORME

Severity:

major

CC:

djm

Priority:

Version:

5.5p1

Hardware:

All

OS:

Linux

Attachments:

Description	Flags
sshd debug and system strace	none

Description Walter.Pfannenmueller 2010-08-09 04:46:21 AEST

Created attachment 1910 [details]
sshd debug and system strace

This was tested on a Suse Linux 11.2

Establishing a port forwarding channel 

ssh -N -R 11001:<clienthost>:443 -o TCPKeepAlive=yes target

and using the channel with 
wget -q --no-check-certificate https://127.0.0.1:11001/

many, many times. 
Every now and then a fd isn't freed again.
In the attachement there is the sshd debug output and
a strace to show that the number of supervised fds in the select call
increase.

The traces are quit big, but not to the bitter end (exhaustion of all fds).

Comment 1 Damien Miller 2010-10-12 14:24:57 AEDT

Hi,

I can't replicate this on OpenBSD or Ubuntu running OpenSSH 5.6. My tests used netcat instead of wget and your unspecified webserver. Could you please try to recreate problem using netcat or similar? It might be possible that you webserver is getting stuck and holding connections open.

Comment 2 Damien Miller 2011-05-06 11:39:01 AEST

We can't reproduce this bug, so I will close it. Please reopen if you have additional information.

Comment 3 Damien Miller 2011-09-06 15:33:10 AEST

close resolved bugs now that openssh-5.9 has been released