SSH2/1 Failure when using bash shell, other shells work

Thu Jan 11 04:11:20 EST 2001

Got a strange problem here.  We have OpenSSH 2.3.0p1 running on a variety of
machines and on one particular Redhat 6.2 machine(all patches applied) we
run into a situation where it will not allow us to start a shell when using
bash or bash2.  csh and others work fine.

One note...if I enable PermitRootLogin, the user root IS allowed to login
with bash.  This is very strange.  I'm guessing it must be some kind of
permissions problem, but I have checked everything I can think of: sshd
configs, pam configs, permissions on user data, permissions on ssh pieces,
etc.

Here is the debug report for SSH Protocol 2. (generated using sshd -ddd)

When using /bin/bash (GNU bash, version 1.14.7(1)) as a shell
When using csh it works fine and allows us to login.

debug1: Seeding random number generator
debug1: read DSA private key done
debug1: Seeding random number generator
debug1: Bind to port 22 on 0.0.0.0.
Server listening on 0.0.0.0 port 22.
Generating 768 bit RSA key.
debug1: Seeding random number generator
debug1: Seeding random number generator
RSA key generation complete.
debug1: Server will not fork when running in debugging mode.
Connection from 206.58.180.12 port 3754
debug1: Client protocol version 2.0; client software version PuTTY
debug1: no match: PuTTY
Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-1.99-OpenSSH_2.3.0p1
debug1: send KEXINIT
debug1: done
debug1: wait KEXINIT
debug1: got kexinit: diffie-hellman-group1-sha1
debug1: got kexinit: ssh-dss
debug1: got kexinit: blowfish-cbc,blowfish-cbc,3des-cbc
debug1: got kexinit: blowfish-cbc,blowfish-cbc,3des-cbc
debug1: got kexinit: hmac-sha1,hmac-md5,none
debug1: got kexinit: hmac-sha1,hmac-md5,none
debug1: got kexinit: none
debug1: got kexinit: none
debug1: got kexinit:
debug1: got kexinit:
debug1: first kex follow: 0
debug1: reserved: 0
debug1: done
debug1: kex: client->server blowfish-cbc hmac-sha1 none
debug1: kex: server->client blowfish-cbc hmac-sha1 none
debug1: Wait SSH2_MSG_KEXDH_INIT.
debug1: bits set: 492/1024
debug1: bits set: 522/1024
debug1: sig size 20 20
debug1: send SSH2_MSG_NEWKEYS.
debug1: done: send SSH2_MSG_NEWKEYS.
debug1: Wait SSH2_MSG_NEWKEYS.
debug1: GOT SSH2_MSG_NEWKEYS.
debug1: done: KEX2.
debug1: userauth-request for user cnewbill service ssh-connection method
password
debug1: attempt #1
debug2: input_userauth_request: setting up authctxt for cnewbill
debug1: Starting up PAM with username "cnewbill"
debug2: input_userauth_request: try method password
debug1: PAM Password authentication accepted for user "cnewbill"
debug1: PAM setting rhost to "cnewbill.onewest.net"
Accepted password for cnewbill from 206.58.180.12 port 3754 ssh2
debug1: Entering interactive session for SSH2.
debug1: server_init_dispatch_20
debug1: server_input_channel_open: ctype session rchan 100 win 32768 max
16384
debug1: open session
debug1: channel 0: new [server-session]
debug1: session_new: init
debug1: session_new: session 0
debug1: session_open: channel 0
debug1: session_open: session 0: link with channel 0
debug1: confirm session
debug2: callback start
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 channel 0 request pty-req reply
1
debug1: session_pty_req: session 0 alloc /dev/pts/4
debug2: callback done
debug2: callback start
debug1: session_by_channel: session 0 channel 0
debug1: session_input_channel_req: session 0 channel 0 request shell reply 1
debug1: PAM setting tty to "/dev/pts/4"
debug1: PAM establishing creds
debug1: fd 7 setting O_NONBLOCK
debug1: fd 3 IS O_NONBLOCK
debug2: callback done
debug1: Setting controlling tty using TIOCSCTTY.
debug2: channel 0: rcvd adjust 315
???debug1: Received SIGCHLD.???
debug1: session_by_pid: pid 4903
debug1: session_exit_message: session 0 channel 0 pid 4903
debug1: session_exit_message: release channel 0
debug1: channel 0: write failed
debug1: channel 0: output open -> closed
debug1: channel 0: close_write
debug1: channel 0: read failed
debug1: channel 0: input open -> drain
debug1: channel 0: close_read
debug1: channel 0: input: no drain shortcut
debug1: channel 0: ibuf empty
debug1: channel 0: input drain -> closed
debug1: channel 0: send eof
debug1: session_pty_cleanup: session 0 release /dev/pts/4
debug1: session_free: session 0 pid 4903
debug1: channel 0: send close
debug2: channel 0: rcvd adjust 7
debug1: channel 0: rcvd close
***fatal: buffer_get: trying to get more bytes than in buffer***
debug1: Calling cleanup 0x805b6f0(0x0)
debug1: Calling cleanup 0x8050980(0x0)
debug1: Calling cleanup 0x8061750(0x0)

Now for SSH Protocol 1 attempt

debug1: sshd version OpenSSH_2.3.0p1
debug1: Seeding random number generator
debug1: read DSA private key done
debug1: Seeding random number generator
debug1: Bind to port 22 on 0.0.0.0.
Server listening on 0.0.0.0 port 22.
Generating 768 bit RSA key.
debug1: Seeding random number generator
debug1: Seeding random number generator
RSA key generation complete.
debug1: Server will not fork when running in debugging mode.
Connection from 206.58.180.12 port 3791
debug1: Client protocol version 1.5; client software version PuTTY
debug1: no match: PuTTY
debug1: Local version string SSH-1.99-OpenSSH_2.3.0p1
debug1: Sent 768 bit public key and 1024 bit host key.
debug1: Encryption type: 3des
debug1: Received session key; encryption turned on.
debug1: Installing crc compensation attack detector.
debug1: Starting up PAM with username "cnewbill"
debug1: Attempting authentication for cnewbill.
Accepted password for cnewbill from 206.58.180.12 port 3791
debug1: PAM setting rhost to "cnewbill.onewest.net"
debug1: session_new: init
debug1: session_new: session 0
debug1: Allocating pty.
debug1: PAM setting tty to "/dev/pts/4"
debug1: PAM establishing creds
debug1: Entering interactive session.
debug1: fd 3 setting O_NONBLOCK
debug1: fd 7 IS O_NONBLOCK
debug1: server_init_dispatch_13
debug1: server_init_dispatch_15
debug1: Setting controlling tty using TIOCSCTTY.
debug1: tvp!=NULL kid 0 mili 10
debug1: tvp!=NULL kid 0 mili 10
debug1: tvp!=NULL kid 0 mili 10
debug1: Received SIGCHLD.
debug1: tvp!=NULL kid 1 mili 100
debug1: End of interactive session; stdin 0, stdout (read 323, sent 323),
stderr 0 bytes.
debug1: Command exited with status 0.
debug1: Received exit confirmation.
debug1: session_pty_cleanup: session 0 release /dev/pts/4
Closing connection to 206.58.180.12

Thanks,

Chris Newbill
Programmer/Analyst
OneWest.net Inc.,
406-449-8056
------------------------------------------------------------
Ever notice how it's a penny for your thoughts, yet you put
in your two-cents? Someone is making a penny on the deal.
-----Steven Wright
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