Bug 2257

Summary:

ssh - Connection closed by UNKNOWN

Product:

Portable OpenSSH

Reporter:

Petr Lautrbach <plautrba>

Component:

ssh

Assignee:

Damien Miller <djm>

Status:

CLOSED FIXED

Severity:

minor

CC:

djm, dtucker

Priority:

Version:

6.6p1

Hardware:

All

OS:

Linux

Attachments:

Description	Flags
add set_remote_ipaddr()	none
improve ECONNRESET error message	none
improved diff; refactor to sshpkt_fatal	dtucker: ok+

Description Petr Lautrbach 2014-07-18 14:32:04 AEST

ssh clients shows "closed by UNKNOWN" message when a socket is closed by a
remote side while ssh is waiting for user's password:

$ ssh user@localhost
user@localhost's password:
Connection closed by UNKNOWN

When the packet_read_seqnr() calls get_remote_ipaddr(), a connection's
socket is already closed and there's not been any other call of this function
yet so canonical_host_ip from canohost.c is still NULL and the function
returns "UNKNOWN". I think that it could be workarounded by calling get_remote_ipaddr() right
after packet_set_connection(), e.g. using another debug message, or
there could be set_remote_ipaddr() in canonhost.c for that.

Comment 1 Petr Lautrbach 2014-07-18 14:35:48 AEST

Created attachment 2457 [details]
add set_remote_ipaddr()

Comment 2 Damien Miller 2015-05-01 14:43:51 AEST

Created attachment 2611 [details]
improve ECONNRESET error message

On -current, just tweaking the error seems sufficient.

$ ./ssh/obj/ssh -p 2222 127.0.0.1                                
djm@127.0.0.1's password: 
Connection reset by 127.0.0.1

Comment 3 Damien Miller 2015-05-01 14:51:44 AEST

Created attachment 2612 [details]
improved diff; refactor to sshpkt_fatal

I just noticed there is already sshpkt_fatal() for this purpose

Comment 4 Damien Miller 2015-05-01 17:10:21 AEST

patch applied - this will be in openssh-6.9

Comment 5 Damien Miller 2015-08-11 23:05:39 AEST

Set all RESOLVED bugs to CLOSED with release of OpenSSH 7.1