linux tcsetattr failed

[John Dunlap]

> localhost sshd[14418]: Setting tty modes failed: Invalid argument

One of our users always causes the above message.  Experimenting with
client side stty settings I found that it can be caused by "stty
parenb" on the client side.  "stty -parenb" stops the error message.

The client runs ssh -V: SSH Version 1.2.31 [rs6000-ibm-aix4.2.0.0],
protocol version 1.5.  Standard version.  Does not use RSAREF.
uname -a: AIX dante21 3 4 00600155C000.  By default on the client,
using csh gives stty parenb, using bash-2.01 gives stty -parenb.

The server runs ssh -V: OpenSSH_2.5.2p2, SSH protocols 1.5/2.0,
OpenSSL 0x0090581f compiled with default ./config (no options),
RHL6.2 with all RHL6.2 updates except new kernel, uname -a: Linux
ohm.apl.washington.edu 2.2.16-3 #1 Mon Jun 19 19:11:44 EDT 2000 i686
unknown,  bash -version: GNU bash, version 1.14.7(1).

The following are results of two runs with max debugging on server
side.  The first is with stty parenb on the client side, the second
is with stty -parenb on the client side.

-- John

server:	sshd -d -d -d -p 99 > /tmp/sshd.parenb 2>&1
client: stty parenb
client: ssh ohm.apl -l jhd -p 99
client: password
server log, /tmp/sshd.parenb:
------------------------ cut here ------------------------------
debug1: Seeding random number generator
debug1: sshd version OpenSSH_2.5.2p2
debug1: load_private_key_autodetect: type 0 RSA1
debug3: Bad RSA1 key file /usr/local/etc/ssh_host_rsa_key.
debug1: read SSH2 private key done: name rsa w/o comment success 1
debug1: load_private_key_autodetect: type 1 RSA
debug3: Bad RSA1 key file /usr/local/etc/ssh_host_dsa_key.
debug1: read SSH2 private key done: name dsa w/o comment success 1
debug1: load_private_key_autodetect: type 2 DSA
socket: Invalid argument
debug1: Bind to port 99 on 0.0.0.0.
Server listening on 0.0.0.0 port 99.
Generating 768 bit RSA key.
RSA key generation complete.
debug1: Server will not fork when running in debugging mode.
Connection from 140.142.8.24 port 1017
debug1: Client protocol version 1.5; client software version 1.2.31
debug1: no match: 1.2.31
debug1: Local version string SSH-1.99-OpenSSH_2.5.2p2
debug1: Sent 768 bit server key and 1024 bit host key.
debug1: Encryption type: blowfish
debug1: Received session key; encryption turned on.
debug1: Installing crc compensation attack detector.
debug1: Attempting authentication for jhd.
Failed rsa for jhd from 140.142.8.24 port 1017
Accepted password for jhd from 140.142.8.24 port 1017
debug1: session_new: init
debug1: session_new: session 0
debug1: Allocating pty.
debug1: Ignoring unsupported tty mode opcode 11 (0xb)
Setting tty modes failed: Invalid argument
debug1: Received request for X11 forwarding with auth spoofing.
debug2: SSH_PROTOFLAG_SCREEN_NUMBER: 1
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6010: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6011: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6012: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6013: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: fd 8 setting O_NONBLOCK
debug1: fd 8 IS O_NONBLOCK
debug1: channel 0: new [X11 inet listener]
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.
debug3: tvp!=NULL kid 0 mili 10
debug3: tvp!=NULL kid 0 mili 10
debug3: tvp!=NULL kid 0 mili 10
debug3: tvp!=NULL kid 0 mili 10
debug1: Received SIGCHLD.
debug3: tvp!=NULL kid 1 mili 100
debug1: End of interactive session; stdin 1, stdout (read 659, sent 659), stderr 0 bytes.
debug1: channel_free: channel 0: status: The following connections are open:

debug1: Command exited with status 0.
debug1: Received exit confirmation.
debug1: session_pty_cleanup: session 0 release /dev/pts/7
debug1: xauthfile_cleanup_proc called
Closing connection to 140.142.8.24
------------------------ cut here ------------------------------


server:	sshd -d -d -d -p 99 > /tmp/sshd.-parenb 2>&1
client: stty -parenb
client: ssh ohm.apl -l jhd -p 99
client: password
server log, /tmp/sshd.-parenb:
------------------------ cut here ------------------------------
debug1: Seeding random number generator
debug1: sshd version OpenSSH_2.5.2p2
debug1: load_private_key_autodetect: type 0 RSA1
debug3: Bad RSA1 key file /usr/local/etc/ssh_host_rsa_key.
debug1: read SSH2 private key done: name rsa w/o comment success 1
debug1: load_private_key_autodetect: type 1 RSA
debug3: Bad RSA1 key file /usr/local/etc/ssh_host_dsa_key.
debug1: read SSH2 private key done: name dsa w/o comment success 1
debug1: load_private_key_autodetect: type 2 DSA
socket: Invalid argument
debug1: Bind to port 99 on 0.0.0.0.
Server listening on 0.0.0.0 port 99.
Generating 768 bit RSA key.
RSA key generation complete.
debug1: Server will not fork when running in debugging mode.
Connection from 140.142.8.24 port 1022
debug1: Client protocol version 1.5; client software version 1.2.31
debug1: no match: 1.2.31
debug1: Local version string SSH-1.99-OpenSSH_2.5.2p2
debug1: Sent 768 bit server key and 1024 bit host key.
debug1: Encryption type: blowfish
debug1: Received session key; encryption turned on.
debug1: Installing crc compensation attack detector.
debug1: Attempting authentication for jhd.
Failed rsa for jhd from 140.142.8.24 port 1022
Accepted password for jhd from 140.142.8.24 port 1022
debug1: session_new: init
debug1: session_new: session 0
debug1: Allocating pty.
debug1: Ignoring unsupported tty mode opcode 11 (0xb)
debug1: Received request for X11 forwarding with auth spoofing.
debug2: SSH_PROTOFLAG_SCREEN_NUMBER: 1
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6010: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6011: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6012: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6013: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: bind port 6014: Address already in use
debug1: x11_create_display_inet: Socket family 10 not supported
debug1: fd 8 setting O_NONBLOCK
debug1: fd 8 IS O_NONBLOCK
debug1: channel 0: new [X11 inet listener]
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.
debug3: tvp!=NULL kid 0 mili 10
debug3: tvp!=NULL kid 0 mili 10
debug3: tvp!=NULL kid 0 mili 10
debug3: tvp!=NULL kid 0 mili 10
debug1: Received SIGCHLD.
debug3: tvp!=NULL kid 1 mili 100
debug1: End of interactive session; stdin 1, stdout (read 659, sent 659), stderr 0 bytes.
debug1: channel_free: channel 0: status: The following connections are open:

debug1: Command exited with status 0.
debug1: Received exit confirmation.
debug1: session_pty_cleanup: session 0 release /dev/pts/7
debug1: xauthfile_cleanup_proc called
Closing connection to 140.142.8.24
------------------------ cut here ------------------------------


-- 
John Dunlap                           University of Washington
Senior Electrical Engineer            Applied Physics Laboratory
dunlap at apl.washington.edu             1013 NE 40th Street
206-543-7207, 543-1300, FAX 543-6785  Seattle, WA   98105-6698