[Bug 1819487] Re: sshd crashed on s390x with hw crypto enabled

[Harald Freudenberger]

enough ffdc data
Thanks

This happens at ibmca destruction time.
Looks like there is some kind of double free or so in the
destructor for the ibmca engine. We had some issues like
this in the past already. I'll have a look onto the code ...

Thanks Frank and Xnox

regards Harald Freudenberger

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Title:
  sshd crashed on s390x with hw crypto enabled

Status in Ubuntu on IBM z Systems:
  Triaged
Status in openssh package in Ubuntu:
  New

Bug description:
  While using today's daily image of disco (either in z/VM or on LPAR)
  and enabling s309x hardware crypto support in openssh, sshd crashes
  with the following messages:

  $ ssh ubuntu at localhost
  The authenticity of host 'localhost (::1)' can't be established.
  ECDSA key fingerprint is SHA256:KoTYC0jCQPtmsOMmBW9DrCiBbkrKTL0leQ/zoIaInNw.
  Are you sure you want to continue connecting (yes/no)? yes
  Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
  ubuntu at localhost's password:
  packet_write_wait: Connection to ::1 port 22: Broken pipe
  (local session is sufficient to reproduce)

  Steps to reproduce - on disco daily:

  $ lsb_release -a
  No LSB modules are available.
  Distributor ID:	Ubuntu
  Description:	Ubuntu Disco Dingo (development branch)
  Release:	19.04
  Codename:	disco
  $ uname -a
  Linux zlin42 5.0.0-7-generic #8-Ubuntu SMP Mon Mar 4 16:25:21 UTC 2019 s390x s390x s390x GNU/Linux

  - enable z hw crypto support for openssh on an Ubuntu host (zlin42) on s390x like this:
  - sudo apt-get install openssl-ibmca libica-utils libica3
  - sudo tee -a /etc/ssl/openssl.cnf < /usr/share/doc/openssl-ibmca/examples/openssl.cnf.sample
  - sudo sed -i 's/^\(openssl_conf = openssl_def.*$\)/# \1/g' /etc/ssl/openssl.cnf
  - sudo sed -i '10i openssl_conf = openssl_def' /etc/ssl/openssl.cnf
  - afterwards ssh login attempts fail (existing session are unaffected):
     $ ssh ubuntu at localhost
     The authenticity of host 'localhost (::1)' can't be established.
     ECDSA key fingerprint is SHA256:KoTYC0jCQPtmsOMmBW9DrCiBbkrKTL0leQ/zoIaInNw.
     Are you sure you want to continue connecting (yes/no)? yes
     Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.
     ubuntu at localhost's password:
     packet_write_wait: Connection to ::1 port 22: Broken pipe

  [94629.032586] User process fault: interruption code 003b ilc:2 in libpthread-2.29.so[3ff7d480000+1c000]
  [94629.032597] Failing address: 0000000000000000 TEID: 0000000000000800
  [94629.032598] Fault in primary space mode while using user ASCE.
  [94629.032601] AS:00000007450281c7 R3:0000000000000024
  [94629.032606] CPU: 0 PID: 8183 Comm: sshd Not tainted 5.0.0-7-generic #8-Ubuntu
  [94629.032607] Hardware name: IBM 2964 N63 400 (LPAR)
  [94629.032608] User PSW : 0705200180000000 000003ff7d48e954
  [94629.032610]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:1 AS:0 CC:2 PM:0 RI:0 EA:3
  [94629.032611] User GPRS: 0000000000000000 0000000000000000 0000000000000000 000003ff7e0085c8
  [94629.032612]            000003ff7e510108 000003ff7db1c3a8 0000000000000000 000003fff857eea0
  [94629.032613]            000003ff7e525040 000002aa3f5ec090 000003ff7e4916f0 000003ff7e4921a8
  [94629.032614]            000003ff7db17c18 0000000000000002 000003ff7e07238a 000003fff857ea20
  [94629.032622] User Code: 000003ff7d48e946: b9040012		lgr	%r1,%r2
                            000003ff7d48e94a: e3f0ff60ff71	lay	%r15,-160(%r15)
                           #000003ff7d48e950: 47000000		bc	0,0
                           >000003ff7d48e954: 58202018		l	%r2,24(%r2)
                            000003ff7d48e958: b24f00b0		ear	%r11,%a0
                            000003ff7d48e95c: ebbb0020000d	sllg	%r11,%r11,32
                            000003ff7d48e962: b24f00b1		ear	%r11,%a1
                            000003ff7d48e966: 5920b0d0		c	%r2,208(%r11)
  [94629.032634] Last Breaking-Event-Address:
  [94629.032638]  [<000003ff7df773b4>] 0x3ff7df773b4

  For more details see attachments ...
  --- 
  ProblemType: Bug
  ApportVersion: 2.20.10-0ubuntu23
  Architecture: s390x
  DistroRelease: Ubuntu 19.04
  Package: openssh-server 1:7.9p1-9
  PackageArchitecture: s390x
  ProcVersionSignature: Ubuntu 5.0.0-7.8-generic 5.0.0
  SSHDConfig: Error: command ['/usr/sbin/sshd', '-T'] failed with exit code -11:
  Tags:  disco
  Uname: Linux 5.0.0-7-generic s390x
  UpgradeStatus: No upgrade log present (probably fresh install)
  UserGroups: pkcs11
  _MarkForUpload: True

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