[Linux-aus] SSH problem

[Anshul Gupta]

Hi All,

I have done a kernel recompilation after adding a few netfilter  
modules. After a reboot I am not able to ssh into the machine. I logged  
in through the backdoor I have created and the logfile on ssh-server  
says,

sshd[686]: ROOT LOGIN REFUSED FROM <IP-ADDRESS-MASKED>
sshd[686]: fatal: monitor_read: unsupported request: 24

On the ssh client,
[root at ssh-client root]# ssh -v -v ssh-server

-----------------------------OUTPUT-----------------------------------
OpenSSH_3.5p1, SSH protocols 1.5/2.0, OpenSSL 0x0090701f
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Rhosts Authentication disabled, originating port will not be  
trusted.
debug1: ssh_connect: needpriv 0
debug1: Connecting to pho [IP_ADDRESS_MASKED] port 22.
debug1: Connection established.
debug1: identity file /root/.ssh/identity type -1
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug2: key_type_from_name: unknown key type '-----END'
debug1: identity file /root/.ssh/id_rsa type 1
debug1: identity file /root/.ssh/id_dsa type -1
debug1: Remote protocol version 2.0, remote software version  
OpenSSH_3.5p1
debug1: match: OpenSSH_3.5p1 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_3.5p1
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit:  
diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:  
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256- 
cbc,rijndael-cbc at lysator.liu.se
debug2: kex_parse_kexinit:  
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256- 
cbc,rijndael-cbc at lysator.liu.se
debug2: kex_parse_kexinit:  
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1 
-96,hmac-md5-96
debug2: kex_parse_kexinit:  
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1 
-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib
debug2: kex_parse_kexinit: none,zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: kex_parse_kexinit:  
diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa,ssh-dss
debug2: kex_parse_kexinit:  
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256- 
cbc,rijndael-cbc at lysator.liu.se
debug2: kex_parse_kexinit:  
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256- 
cbc,rijndael-cbc at lysator.liu.se
debug2: kex_parse_kexinit:  
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1 
-96,hmac-md5-96
debug2: kex_parse_kexinit:  
hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160 at openssh.com,hmac-sha1 
-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib
debug2: kex_parse_kexinit: none,zlib
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit:
debug2: kex_parse_kexinit: first_kex_follows 0
debug2: kex_parse_kexinit: reserved 0
debug2: mac_init: found hmac-md5
debug1: kex: server->client aes128-cbc hmac-md5 none
debug2: mac_init: found hmac-md5
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: dh_gen_key: priv key bits set: 142/256
debug1: bits set: 1623/3191
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Host 'pho' is known and matches the RSA host key.
debug1: Found key in /root/.ssh/known_hosts:4
debug1: bits set: 1614/3191
debug1: ssh_rsa_verify: signature correct
debug1: kex_derive_keys
debug1: newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: waiting for SSH2_MSG_NEWKEYS
debug1: newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: done: ssh_kex2.
debug1: send SSH2_MSG_SERVICE_REQUEST
debug1: service_accept: ssh-userauth
debug1: got SSH2_MSG_SERVICE_ACCEPT
debug1: authentications that can continue:  
publickey,password,keyboard-interactive
debug1: next auth method to try is publickey
debug1: try privkey: /root/.ssh/identity
debug1: try pubkey: /root/.ssh/id_rsa
debug2: we sent a publickey packet, wait for reply
debug1: input_userauth_pk_ok: pkalg ssh-rsa blen 149 lastkey 0x808fed8  
hint 1
debug2: input_userauth_pk_ok: fp  
b7:45:0c:51:d4:9a:4f:2a:a3:f5:05:a7:c5:23:de:6e
debug1: read PEM private key done: type RSA
debug1: ssh-userauth2 successful: method publickey
debug1: channel 0: new [client-session]
debug1: send channel open 0
debug1: Entering interactive session.
debug1: channel_free: channel 0: client-session, nchannels 1
Read from remote host pho: Connection reset by peer
Connection to pho closed.
debug1: Transferred: stdin 0, stdout 0, stderr 80 bytes in 0.0 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 48016.5
debug1: Exit status -1
------------END OF OUTPUT---------------------------

Has anyone faced this problem? Is this a bug?

Cheers,
Anshul