FS#29049 - [OpenSSH] segmentation fault using key exchange

Attached to Project: Arch Linux
Opened by Rakesh Singh (rakeshsingh) - Thursday, 22 March 2012, 07:44 GMT
Last edited by Gaetan Bisson (vesath) - Thursday, 22 March 2012, 09:49 GMT
Task Type Bug Report
Category Packages: Core
Status Closed
Assigned To Gaetan Bisson (vesath)
Architecture All
Severity Medium
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No

Details

Description: OpenSSH crashes with exit code 139 (Segmentation fault) when connection to remote server using authorized keys.


Additional info:
openssh 5.9p1-8
openssl 1.0.1-1


Pacman log:
[2012-03-21 12:39] synchronizing package lists
[2012-03-21 12:41] starting full system upgrade
[2012-03-21 12:52] upgraded bash (4.2.024-1 -> 4.2.024-2)
[2012-03-21 12:52] upgraded device-mapper (2.02.90-1 -> 2.02.95-1)
[2012-03-21 12:52] upgraded iproute2 (3.2.0-2 -> 3.2.0-3)
[2012-03-21 12:52] upgraded libdrm (2.4.31-1 -> 2.4.32-1)
[2012-03-21 12:52] upgraded mercurial (2.1.1-1 -> 2.1.1-2)
[2012-03-21 12:52] upgraded neon (0.29.6-3 -> 0.29.6-4)
[2012-03-21 12:52] upgraded openssl (1.0.0.h-1 -> 1.0.1-1)
[2012-03-21 12:52] upgraded openssh (5.9p1-5 -> 5.9p1-8)
[2012-03-21 12:52] upgraded psmisc (22.15-1 -> 22.16-1)
[2012-03-21 12:52] upgraded vim-runtime (7.3.434-1 -> 7.3.475-1)
[2012-03-21 12:52] upgraded vim (7.3.434-1 -> 7.3.475-1)


SSH client with debug level 3:
ssh -v -v -v hisuper@hipfasdv
OpenSSH_5.9p1, OpenSSL 1.0.1 14 Mar 2012
debug1: Reading configuration data /data/users/rakeshs/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug2: ssh_connect: needpriv 0
debug1: Connecting to hipfasdv [10.147.1.121] port 22.
debug1: Connection established.
debug3: Incorrect RSA1 identifier
debug3: Could not load "/data/users/rakeshs/.ssh/id_rsa" as a RSA1 public key
debug1: identity file /data/users/rakeshs/.ssh/id_rsa type 1
debug1: identity file /data/users/rakeshs/.ssh/id_rsa-cert type -1
debug3: Incorrect RSA1 identifier
debug3: Could not load "/data/users/rakeshs/.ssh/id_dsa" as a RSA1 public key
debug1: identity file /data/users/rakeshs/.ssh/id_dsa type 2
debug1: identity file /data/users/rakeshs/.ssh/id_dsa-cert type -1
debug1: identity file /data/users/rakeshs/.ssh/id_ecdsa type -1
debug1: identity file /data/users/rakeshs/.ssh/id_ecdsa-cert type -1
debug1: Remote protocol version 1.99, remote software version OpenSSH_3.6.1p1-1
debug1: match: OpenSSH_3.6.1p1-1 pat OpenSSH_3.*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.9
debug2: fd 3 setting O_NONBLOCK
debug3: load_hostkeys: loading entries for host "hipfasdv" from file "/data/users/rakeshs/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /data/users/rakeshs/.ssh/known_hosts:70
debug3: load_hostkeys: loaded 1 keys
debug3: load_hostkeys: loading entries for host "hipfasdv" from file "/data/users/rakeshs/.ssh/known_hosts2"
debug3: load_hostkeys: loaded 0 keys
debug3: order_hostkeyalgs: prefer hostkeyalgs: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug2: kex_parse_kexinit: ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1
debug2: kex_parse_kexinit: ssh-rsa-cert-v01@openssh.com,ssh-rsa-cert-v00@openssh.com,ssh-rsa,ecdsa-sha2-nistp256-cert-v01@openssh.com,ecdsa-sha2-nistp384-cert-v01@openssh.com,ecdsa-sha2-nistp521-cert-v01@openssh.com,ssh-dss-cert-v01@openssh.com,ssh-dss-cert-v00@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,ssh-dss
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,aes192-cbc,aes256-cbc,arcfour,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,umac-64@openssh.com,hmac-sha2-256,hmac-sha2-256-96,hmac-sha2-512,hmac-sha2-512-96,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: none,zlib@openssh.com,zlib
debug2: kex_parse_kexinit: none,zlib@openssh.com,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@lysator.liu.se
debug2: kex_parse_kexinit: aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@openssh.com,hmac-sha1-96,hmac-md5-96
debug2: kex_parse_kexinit: hmac-md5,hmac-sha1,hmac-ripemd160,hmac-ripemd160@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_setup: found hmac-md5
debug1: kex: server->client aes128-cbc hmac-md5 none
debug2: mac_setup: found hmac-md5
debug1: kex: client->server aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug2: dh_gen_key: priv key bits set: 123/256
debug2: bits set: 512/1024
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: Server host key: RSA 8b:08:3e:ba:0b:e0:6f:cc:ef:a0:24:8e:cc:e9:d8:83
debug3: load_hostkeys: loading entries for host "hipfasdv" from file "/data/users/rakeshs/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /data/users/rakeshs/.ssh/known_hosts:70
debug3: load_hostkeys: loaded 1 keys
debug3: load_hostkeys: loading entries for host "hipfasdv" from file "/data/users/rakeshs/.ssh/known_hosts2"
debug3: load_hostkeys: loaded 0 keys
debug3: load_hostkeys: loading entries for host "10.147.1.121" from file "/data/users/rakeshs/.ssh/known_hosts"
debug3: load_hostkeys: found key type RSA in file /data/users/rakeshs/.ssh/known_hosts:169
debug3: load_hostkeys: loaded 1 keys
debug3: load_hostkeys: loading entries for host "10.147.1.121" from file "/data/users/rakeshs/.ssh/known_hosts2"
debug3: load_hostkeys: loaded 0 keys
debug1: Host 'hipfasdv' is known and matches the RSA host key.
debug1: Found key in /data/users/rakeshs/.ssh/known_hosts:70
debug2: bits set: 482/1024
debug1: ssh_rsa_verify: signature correct
debug2: kex_derive_keys
debug2: set_newkeys: mode 1
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug2: set_newkeys: mode 0
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug2: key: /data/users/rakeshs/.ssh/id_rsa (0x835f1f0)
debug2: key: /data/users/rakeshs/.ssh/id_dsa (0x83607f8)
debug2: key: /data/users/rakeshs/.ssh/id_ecdsa ((nil))
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug3: start over, passed a different list publickey,password,keyboard-interactive
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Offering RSA public key: /data/users/rakeshs/.ssh/id_rsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Offering DSA public key: /data/users/rakeshs/.ssh/id_dsa
debug3: send_pubkey_test
debug2: we sent a publickey packet, wait for reply
debug1: Server accepts key: pkalg ssh-dss blen 434
debug2: input_userauth_pk_ok: fp 48:9a:28:01:11:e2:80:6d:d3:33:8e:a4:48:af:c3:aa
debug3: sign_and_send_pubkey: DSA 48:9a:28:01:11:e2:80:6d:d3:33:8e:a4:48:af:c3:aa
debug1: read PEM private key done: type DSA
Segmentation fault


Steps to reproduce: Run ssh from the client to a user on a server that has authorized keys setup.
This task depends upon

Closed by  Gaetan Bisson (vesath)
Thursday, 22 March 2012, 09:49 GMT
Reason for closing:  Upstream
Comment by Rakesh Singh (rakeshsingh) - Thursday, 22 March 2012, 08:40 GMT
This seems to be only occurring when connecting to UNIX (AIX and Solaris SSH servers), even without key exchange.
I have tested 3 AIX hosts and 2 Solaris hosts with key exchange enabled and disabled.
All 4 crashed.

AIX 5.3 Packages :
$ lslpp -L | grep -i opens
openssh 3.6.1.1 C F OpenSSH 3.6.1p1-1 Portable for
openssh.base.server 3.8.0.2 ? F Open Secure Shell Server
openssh.license 3.8.0.2 C F Open Secure Shell License
openssl 0.9.6g-3 C R Secure Sockets Layer and
openssl-devel 0.9.6g-3 C R Secure Sockets Layer and
openssl-doc 0.9.6g-3 C R OpenSSL miscellaneous files

I have connected to another Arch Linux machine and 2 OpenSuse servers without a problem.
The other Arch machine has not been updated in a while and running openssh 5.9p1-5, so I am using this to connect to our UNIX servers.
Comment by Gaetan Bisson (vesath) - Thursday, 22 March 2012, 09:12 GMT
With openssh-5.9p1-8, I can perfectly well SSH into a SunOS 5.10 box running Sun_SSH_1.1.5, SSH protocols 1.5/2.0, OpenSSL 0x0090704f.

Please make sure your system is entirely up-to-date, see if the issue goes away when you rebuild openssh from source, and otherwise consider filing a bug report upstream.
Comment by Gaetan Bisson (vesath) - Thursday, 22 March 2012, 09:13 GMT
Note: The issue very likely lies in OpenSSL.
Comment by Rakesh Singh (rakeshsingh) - Thursday, 22 March 2012, 09:41 GMT
The client PC (Arch) is synced daily.
I can confirm that the problem occurs only on the AIX servers running OpenSSH 3.6 with OpenSSL 0.9.6
(which unfortunately is the default on AIX 5.3).
I tested on another AIX 5.3 server where I installed a different version of OpenSSH (4.3), and it connects fine.
Connecting to AIX 6.1 running OpenSSH 5.2 and OpenSSL 0.9.8 connects fine as well.

So the new OpenSSH only has a problem with these very old server packages.

This issue can be closed as it is not Arch related, but rather the new OpenSSH that breaks compatibility with the old SSH packages.

Thanks



Comment by Gaetan Bisson (vesath) - Thursday, 22 March 2012, 09:49 GMT
Alright. Feel free to reopen this issue if/when you find a fix that I can incorporate to our package.

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