Bug#298427: sshd on user-mode-linux segfaults with "UsePAM yes"
Package: ssh
Version: 1:3.8.1p1-8.sarge.4
Package: libpam-ldap
Version: 169-1
User Mode Linux Kernel 2.6.10, self-compiled
Host system = 2.6.8, self compiled
(A special combination - I know)
Hello!
Trying to login to a sarge user-mode-linux installation with
pam
results a segmentation fault:
User-Mode-Linux Client /etc/ssh/sshd_config =
Port 22
Protocol 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
UsePrivilegeSeparation yes
KeyRegenerationInterval 3600
ServerKeyBits 768
SyslogFacility AUTH
LogLevel INFO
LoginGraceTime 600
PermitRootLogin no
StrictModes yes
RSAAuthentication yes
PubkeyAuthentication yes
IgnoreRhosts yes
RhostsRSAAuthentication no
HostbasedAuthentication no
PermitEmptyPasswords no
PasswordAuthentication yes
X11Forwarding no
X11DisplayOffset 10
PrintMotd no
PrintLastLog yes
KeepAlive yes
Subsystem sftp /usr/lib/sftp-server
UsePAM yes
SSH-Client = User-Mode-Linux host:
aic1:$ ssh mafaulst@10.7.101.10
Connection closed by 10.7.101.10
SSH-Server = User-Mode-Linux-Client
aic-students:/home/mafaulst# sshd -d -d -d
debug2: read_server_config: filename /etc/ssh/sshd_config
debug1: sshd version OpenSSH_3.8.1p1 Debian-8.sarge.4
debug3: Not a RSA1 key file /etc/ssh/ssh_host_rsa_key.
debug1: read PEM private key done: type RSA
debug1: private host key: #0 type 1 RSA
debug3: Not a RSA1 key file /etc/ssh/ssh_host_dsa_key.
debug1: read PEM private key done: type DSA
debug1: private host key: #1 type 2 DSA
socket: Address family not supported by protocol
debug1: Bind to port 22 on 0.0.0.0.
Server listening on 0.0.0.0 port 22.
debug1: Server will not fork when running in debugging mode.
Connection from 10.7.101.1 port 33039
debug1: Client protocol version 2.0; client software version OpenSSH_3.8.1p1
Debian-8.sarge.4
debug1: match: OpenSSH_3.8.1p1 Debian-8.sarge.4 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_3.8.1p1 Debian-8.sarge.4
debug3: privsep user:group 100:65534
debug1: permanently_set_uid: 100/65534
debug1: list_hostkey_types: ssh-rsa,ssh-dss
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@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit:
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
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: 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,aes128-ctr,aes192-ctr,aes256-ctr
debug2: kex_parse_kexinit:
aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc,rijndael-cbc@lysator.liu.se,aes128-ctr,aes192-ctr,aes256-ctr
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_init: found hmac-md5
debug1: kex: client->server aes128-cbc hmac-md5 none
debug2: mac_init: found hmac-md5
debug1: kex: server->client aes128-cbc hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST received
debug3: mm_request_send entering: type 0
debug3: mm_choose_dh: waiting for MONITOR_ANS_MODULI
debug3: mm_request_receive_expect entering: type 1
debug3: mm_request_receive entering
debug2: Network child is on pid 266
debug3: preauth child monitor started
debug3: mm_request_receive entering
debug3: monitor_read: checking request 0
debug3: mm_answer_moduli: got parameters: 1024 1024 8192
debug3: mm_request_send entering: type 1
debug2: monitor_read: 0 used once, disabling now
debug3: mm_request_receive entering
debug3: mm_choose_dh: remaining 0
debug1: SSH2_MSG_KEX_DH_GEX_GROUP sent
debug2: dh_gen_key: priv key bits set: 136/256
debug2: bits set: 540/1024
debug1: expecting SSH2_MSG_KEX_DH_GEX_INIT
debug2: bits set: 488/1024
debug3: mm_key_sign entering
debug3: mm_request_send entering: type 4
debug3: monitor_read: checking request 4
debug3: mm_answer_sign
debug3: mm_answer_sign: signature 0x8096020(143)
debug3: mm_request_send entering: type 5
debug2: monitor_read: 4 used once, disabling now
debug3: mm_request_receive entering
debug3: mm_key_sign: waiting for MONITOR_ANS_SIGN
debug3: mm_request_receive_expect entering: type 5
debug3: mm_request_receive entering
debug1: SSH2_MSG_KEX_DH_GEX_REPLY sent
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: KEX done
debug1: userauth-request for user mafaulst service ssh-connection method none
debug1: attempt 0 failures 0
debug3: mm_getpwnamallow entering
debug3: mm_request_send entering: type 6
debug3: monitor_read: checking request 6
debug3: mm_answer_pwnamallow
debug3: mm_getpwnamallow: waiting for MONITOR_ANS_PWNAM
debug3: mm_request_receive_expect entering: type 7
debug3: mm_request_receive entering
debug3: mm_answer_pwnamallow: sending MONITOR_ANS_PWNAM: 1
debug3: mm_request_send entering: type 7
debug2: monitor_read: 6 used once, disabling now
debug3: mm_request_receive entering
debug2: input_userauth_request: setting up authctxt for mafaulst
debug3: mm_start_pam entering
debug3: mm_request_send entering: type 45
debug3: monitor_read: checking request 45
debug1: PAM: initializing for "mafaulst"
debug3: Trying to reverse map address 10.7.101.1.
debug3: mm_inform_authserv entering
debug3: mm_request_send entering: type 3
debug2: input_userauth_request: try method none
debug3: mm_auth_password entering
debug1: PAM: setting PAM_RHOST to "10.7.101.1"
debug1: PAM: setting PAM_TTY to "ssh"
debug2: monitor_read: 45 used once, disabling now
debug3: mm_request_receive entering
debug3: monitor_read: checking request 3
debug3: mm_answer_authserv: service=ssh-connection, style=
debug2: monitor_read: 3 used once, disabling now
debug3: mm_request_receive entering
debug3: mm_request_send entering: type 10
debug3: monitor_read: checking request 10
debug3: mm_answer_authpassword: sending result 0
debug3: mm_request_send entering: type 11
Failed none for mafaulst from 10.7.101.1 port 33039 ssh2
debug3: mm_request_receive entering
debug3: mm_auth_password: waiting for MONITOR_ANS_AUTHPASSWORD
debug3: mm_request_receive_expect entering: type 11
debug3: mm_request_receive entering
debug3: mm_auth_password: user not authenticated
Failed none for mafaulst from 10.7.101.1 port 33039 ssh2
debug1: userauth-request for user mafaulst service ssh-connection method
keyboard-interactive
debug1: attempt 1 failures 1
debug2: input_userauth_request: try method keyboard-interactive
debug1: keyboard-interactive devs
debug1: auth2_challenge: user=mafaulst devs=
debug1: kbdint_alloc: devices 'pam'
debug2: auth2_challenge_start: devices pam
debug2: kbdint_next_device: devices <empty>
debug1: auth2_challenge_start: trying authentication method 'pam'
debug3: mm_sshpam_init_ctx
debug3: mm_request_send entering: type 48
debug3: monitor_read: checking request 48
debug3: mm_answer_pam_init_ctx
debug3: PAM: sshpam_init_ctx entering
debug3: mm_request_send entering: type 49
debug3: mm_request_receive entering
debug3: mm_sshpam_init_ctx: waiting for MONITOR_ANS_PAM_INIT_CTX
debug3: mm_request_receive_expect entering: type 49
debug3: mm_request_receive entering
debug3: mm_sshpam_query
debug3: mm_request_send entering: type 50
debug3: monitor_read: checking request 50
debug3: mm_answer_pam_query
debug3: PAM: sshpam_query entering
debug3: ssh_msg_recv entering
debug3: mm_sshpam_query: waiting for MONITOR_ANS_PAM_QUERY
debug3: mm_request_receive_expect entering: type 51
debug3: mm_request_receive entering
Segmentation fault
aic-students:/home/mafaulst# debug1: do_cleanup
debug1: PAM: cleanup
debug3: PAM: sshpam_thread_cleanup entering
Hints:
- Console login for the user is OK.
- SSH for local (passwd/shadow) works with
PasswordAuthentication yes
- Trying to login users in a ldap database with libpam-ldap
results a segmentation fault, too.
Kind Regards
Matthias Faulstich
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