[Bug 1761737] Re: [bionic] samba PANIC, INTERNAL ERROR: Signal 11

Tue Apr 17 13:31:47 UTC 2018

Ok

The smb.conf(5) manpage does state that for "security = ads" or "server
role = member server" to work, the machine must have been joined to the
domain via "net ads join". This is what creates the necessary secrets in
the local secrets tdb database.

My hypothesis is that there was a change in 4.7.x and that when the
secrets are not found, it crashes. Definitely a bug, but we might be in
an unsupported configuration. I have yet to hear from upstream in their
bug.

Here is what we could try:

a) Samba as a standalone server, but using kerberos for authentication. The users will exist "locally" via sssd, and samba will be just like any other kerberized service authenticating the users via the kdc. For that it will need an appropriate service key in /etc/krb5.keytab. I think realm (the tool) only extracts host/* keys, not cifs/* keys, and samba might want cifs/* ones.
Note that the realm tool does not change smb.conf as far as I can see, that's why you still had "security = user" or "server role = stanalone server" in your smb.conf before. That might be a hint.

Also, we have to be careful in this configuration to use the same
username format. SSSD by default likes "username at REALM.COM", and samba
might expect just "username", or "username at WORKGROUP". That kind of
thing.

b) Samba as a normal member server. For this you would have to use "net
ads join". I'm not sure if this would require winbind, probably not.

I can try both scenarios in a clean VM, but I'm a bit out of time and
can't commit to it just yet. If we can't address this for the release,
then an SRU is in order.

I also just tried 4.7.7 quickly and can still reproduce the crash with
the minimal smb.conf I showed in the upstream bug at
https://bugzilla.samba.org/show_bug.cgi?id=13376.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to samba in Ubuntu.
https://bugs.launchpad.net/bugs/1761737

Title:
  [bionic] samba PANIC, INTERNAL ERROR: Signal 11

Status in samba:
  Unknown
Status in samba package in Ubuntu:
  Confirmed

Bug description:
  Our Ubuntu clients are in an AD domain using realm. Accessing a samba share (SSO) with dolphin/nautilus (smb://HOST/share) is working on ubuntu clients where the host with the shared directory is ubuntu 16.04 or 17.10.
  Accessing the shared folder on ubuntu 18.04 with same configuration as 16.04 or 17.10 clients throws a panic on the system with 18.04:

  /var/log/samba/log.LOCALHOST on HOST with 18.04
  ===============================================

  [2018/04/06 13:43:50.360655,  5] ../source3/smbd/reply.c:780(reply_special)
    init msg_type=0x81 msg_flags=0x0
  [2018/04/06 13:43:50.361179,  3] ../source3/smbd/process.c:1959(process_smb)
    Transaction 0 of length 194 (0 toread)
  [2018/04/06 13:43:50.361241,  5] ../source3/lib/util.c:184(show_msg)
  [2018/04/06 13:43:50.361264,  5] ../source3/lib/util.c:194(show_msg)
    size=190
    smb_com=0x72
    smb_rcls=0
    smb_reh=0
    smb_err=0
    smb_flg=24
    smb_flg2=51267
    smb_tid=0
    smb_pid=65534
    smb_uid=0
    smb_mid=0
    smt_wct=0
    smb_bcc=155
  [2018/04/06 13:43:50.361467,  3] ../source3/smbd/process.c:1539(switch_message)
    switch message SMBnegprot (pid 2538) conn 0x0
  [2018/04/06 13:43:50.361554,  4] ../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
    setting sec ctx (0, 0) - sec_ctx_stack_ndx = 0
  [2018/04/06 13:43:50.361617,  5] ../libcli/security/security_token.c:53(security_token_debug)
    Security token: (NULL)
  [2018/04/06 13:43:50.361667,  5] ../source3/auth/token_util.c:651(debug_unix_user_token)
    UNIX token of user 0
    Primary group is 0 and contains 0 supplementary groups
  [2018/04/06 13:43:50.361766,  5] ../source3/smbd/uid.c:425(smbd_change_to_root_user)
    change_to_root_user: now uid=(0,0) gid=(0,0)
  [2018/04/06 13:43:50.363559,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [PC NETWORK PROGRAM 1.0]
  [2018/04/06 13:43:50.363638,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [MICROSOFT NETWORKS 1.03]
  [2018/04/06 13:43:50.363677,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [MICROSOFT NETWORKS 3.0]
  [2018/04/06 13:43:50.363712,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [LANMAN1.0]
  [2018/04/06 13:43:50.363747,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [LM1.2X002]
  [2018/04/06 13:43:50.363782,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [DOS LANMAN2.1]
  [2018/04/06 13:43:50.363817,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [LANMAN2.1]
  [2018/04/06 13:43:50.363852,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [Samba]
  [2018/04/06 13:43:50.363888,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [NT LANMAN 1.0]
  [2018/04/06 13:43:50.363924,  3] ../source3/smbd/negprot.c:612(reply_negprot)
    Requested protocol [NT LM 0.12]
  [2018/04/06 13:43:50.364019,  5] ../lib/dbwrap/dbwrap.c:160(dbwrap_check_lock_order)
    check lock order 2 for /var/run/samba/serverid.tdb
  [2018/04/06 13:43:50.364077,  5] ../lib/dbwrap/dbwrap.c:128(dbwrap_lock_order_state_destructor)
    release lock order 2 for /var/run/samba/serverid.tdb
  [2018/04/06 13:43:50.364259,  5] ../source3/auth/auth.c:537(make_auth3_context_for_ntlm)
    Making default auth method list for server role = 'standalone server', encrypt passwords = yes
  [2018/04/06 13:43:50.364282,  5] ../source3/auth/auth.c:48(smb_register_auth)
    Attempting to register auth backend trustdomain
  [2018/04/06 13:43:50.364300,  5] ../source3/auth/auth.c:60(smb_register_auth)
    Successfully added auth method 'trustdomain'
  [2018/04/06 13:43:50.364316,  5] ../source3/auth/auth.c:48(smb_register_auth)
    Attempting to register auth backend ntdomain
  [2018/04/06 13:43:50.364334,  5] ../source3/auth/auth.c:60(smb_register_auth)
    Successfully added auth method 'ntdomain'
  [2018/04/06 13:43:50.364352,  5] ../source3/auth/auth.c:48(smb_register_auth)
    Attempting to register auth backend guest
  [2018/04/06 13:43:50.364364,  5] ../source3/auth/auth.c:60(smb_register_auth)
    Successfully added auth method 'guest'
  [2018/04/06 13:43:50.364392,  5] ../source3/auth/auth.c:48(smb_register_auth)
    Attempting to register auth backend sam
  [2018/04/06 13:43:50.364404,  5] ../source3/auth/auth.c:60(smb_register_auth)
    Successfully added auth method 'sam'
  [2018/04/06 13:43:50.364415,  5] ../source3/auth/auth.c:48(smb_register_auth)
    Attempting to register auth backend sam_ignoredomain
  [2018/04/06 13:43:50.364427,  5] ../source3/auth/auth.c:60(smb_register_auth)
    Successfully added auth method 'sam_ignoredomain'
  [2018/04/06 13:43:50.364438,  5] ../source3/auth/auth.c:48(smb_register_auth)
    Attempting to register auth backend sam_netlogon3
  [2018/04/06 13:43:50.364450,  5] ../source3/auth/auth.c:60(smb_register_auth)
    Successfully added auth method 'sam_netlogon3'
  [2018/04/06 13:43:50.364461,  5] ../source3/auth/auth.c:48(smb_register_auth)
    Attempting to register auth backend winbind
  [2018/04/06 13:43:50.364473,  5] ../source3/auth/auth.c:60(smb_register_auth)
    Successfully added auth method 'winbind'
  [2018/04/06 13:43:50.364484,  5] ../source3/auth/auth.c:48(smb_register_auth)
    Attempting to register auth backend unix
  [2018/04/06 13:43:50.364502,  5] ../source3/auth/auth.c:60(smb_register_auth)
    Successfully added auth method 'unix'
  [2018/04/06 13:43:50.364514,  5] ../source3/auth/auth.c:400(load_auth_module)
    load_auth_module: Attempting to find an auth method to match guest
  [2018/04/06 13:43:50.364527,  5] ../source3/auth/auth.c:425(load_auth_module)
    load_auth_module: auth method guest has a valid init
  [2018/04/06 13:43:50.364539,  5] ../source3/auth/auth.c:400(load_auth_module)
    load_auth_module: Attempting to find an auth method to match sam_ignoredomain
  [2018/04/06 13:43:50.364551,  5] ../source3/auth/auth.c:425(load_auth_module)
    load_auth_module: auth method sam_ignoredomain has a valid init
  [2018/04/06 13:43:50.365880,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'gssapi_spnego' registered
  [2018/04/06 13:43:50.365916,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'gssapi_krb5' registered
  [2018/04/06 13:43:50.365930,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'gssapi_krb5_sasl' registered
  [2018/04/06 13:43:50.365942,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'spnego' registered
  [2018/04/06 13:43:50.365954,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'schannel' registered
  [2018/04/06 13:43:50.365967,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'naclrpc_as_system' registered
  [2018/04/06 13:43:50.365979,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'sasl-EXTERNAL' registered
  [2018/04/06 13:43:50.365992,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'ntlmssp' registered
  [2018/04/06 13:43:50.366004,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'ntlmssp_resume_ccache' registered
  [2018/04/06 13:43:50.366017,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'http_basic' registered
  [2018/04/06 13:43:50.366029,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'http_ntlm' registered
  [2018/04/06 13:43:50.366042,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'krb5' registered
  [2018/04/06 13:43:50.366055,  3] ../auth/gensec/gensec_start.c:977(gensec_register)
    GENSEC backend 'fake_gssapi_krb5' registered
  [2018/04/06 13:43:50.366109,  5] ../auth/gensec/gensec_start.c:739(gensec_start_mech)
    Starting GENSEC mechanism spnego
  [2018/04/06 13:43:50.366144,  5] ../auth/gensec/gensec_start.c:739(gensec_start_mech)
    Starting GENSEC submechanism gse_krb5
  [2018/04/06 13:43:50.366323,  0] ../lib/util/fault.c:78(fault_report)
    ===============================================================
  [2018/04/06 13:43:50.366346,  0] ../lib/util/fault.c:79(fault_report)
    INTERNAL ERROR: Signal 11 in pid 2538 (4.7.6-Ubuntu)
    Please read the Trouble-Shooting section of the Samba HOWTO
  [2018/04/06 13:43:50.366368,  0] ../lib/util/fault.c:81(fault_report)
    ===============================================================
  [2018/04/06 13:43:50.366387,  0] ../source3/lib/util.c:815(smb_panic_s3)
    PANIC (pid 2538): internal error
  [2018/04/06 13:43:50.366896,  0] ../source3/lib/util.c:926(log_stack_trace)
    BACKTRACE: 33 stack frames:
     #0 /usr/lib/x86_64-linux-gnu/libsmbconf.so.0(log_stack_trace+0x1f) [0x7f738c2bd9cf]
     #1 /usr/lib/x86_64-linux-gnu/libsmbconf.so.0(smb_panic_s3+0x20) [0x7f738c2bdaa0]
     #2 /usr/lib/x86_64-linux-gnu/libsamba-util.so.0(smb_panic+0x2f) [0x7f738e3a65af]
     #3 /usr/lib/x86_64-linux-gnu/libsamba-util.so.0(+0x197c6) [0x7f738e3a67c6]
     #4 /lib/x86_64-linux-gnu/libpthread.so.0(+0x12890) [0x7f738e817890]
     #5 /usr/lib/x86_64-linux-gnu/samba/libgse.so.0(+0x8070) [0x7f73866c5070]
     #6 /usr/lib/x86_64-linux-gnu/samba/libgse.so.0(gse_krb5_get_server_keytab+0x95) [0x7f73866c5ac5]
     #7 /usr/lib/x86_64-linux-gnu/samba/libgse.so.0(+0xac89) [0x7f73866c7c89]
     #8 /usr/lib/x86_64-linux-gnu/samba/libgensec.so.0(+0x187a5) [0x7f73864ab7a5]
     #9 /usr/lib/x86_64-linux-gnu/samba/libgensec.so.0(+0xa2a7) [0x7f738649d2a7]
     #10 /usr/lib/x86_64-linux-gnu/samba/libgensec.so.0(+0xb7fe) [0x7f738649e7fe]
     #11 /usr/lib/x86_64-linux-gnu/samba/libgensec.so.0(gensec_update_ev+0x64) [0x7f73864aafa4]
     #12 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0(negprot_spnego+0xa8) [0x7f738df764f8]
     #13 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0(+0x12ba3b) [0x7f738df76a3b]
     #14 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0(reply_negprot+0x4e3) [0x7f738df771f3]
     #15 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0(+0x1814ca) [0x7f738dfcc4ca]
     #16 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0(+0x183aee) [0x7f738dfceaee]
     #17 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0(+0x1849fc) [0x7f738dfcf9fc]
     #18 /usr/lib/x86_64-linux-gnu/libtevent.so.0(+0x9ed0) [0x7f738aeefed0]
     #19 /usr/lib/x86_64-linux-gnu/libtevent.so.0(+0x8357) [0x7f738aeee357]
     #20 /usr/lib/x86_64-linux-gnu/libtevent.so.0(_tevent_loop_once+0x9d) [0x7f738aeea7cd]
     #21 /usr/lib/x86_64-linux-gnu/libtevent.so.0(tevent_common_loop_wait+0x1b) [0x7f738aeea9eb]
     #22 /usr/lib/x86_64-linux-gnu/libtevent.so.0(+0x82f7) [0x7f738aeee2f7]
     #23 /usr/lib/x86_64-linux-gnu/samba/libsmbd-base.so.0(smbd_process+0x718) [0x7f738dfd0d78]
     #24 /usr/sbin/smbd(+0xcfcc) [0x55a15e207fcc]
     #25 /usr/lib/x86_64-linux-gnu/libtevent.so.0(+0x9ed0) [0x7f738aeefed0]
     #26 /usr/lib/x86_64-linux-gnu/libtevent.so.0(+0x8357) [0x7f738aeee357]
     #27 /usr/lib/x86_64-linux-gnu/libtevent.so.0(_tevent_loop_once+0x9d) [0x7f738aeea7cd]
     #28 /usr/lib/x86_64-linux-gnu/libtevent.so.0(tevent_common_loop_wait+0x1b) [0x7f738aeea9eb]
     #29 /usr/lib/x86_64-linux-gnu/libtevent.so.0(+0x82f7) [0x7f738aeee2f7]
     #30 /usr/sbin/smbd(main+0x1d0a) [0x55a15e20334a]
     #31 /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xe7) [0x7f738ab16b97]
     #32 /usr/sbin/smbd(_start+0x2a) [0x55a15e20345a]
  [2018/04/06 13:43:50.367078,  0] ../source3/lib/util.c:827(smb_panic_s3)
    smb_panic(): calling panic action [/usr/share/samba/panic-action 2538]
  30      ../sysdeps/unix/sysv/linux/waitpid.c: No such file or directory.
  mail: cannot send message: Process exited with a non-zero status
  [2018/04/06 13:43:51.587520,  0] ../source3/lib/util.c:835(smb_panic_s3)
    smb_panic(): action returned status 36
  [2018/04/06 13:43:51.587618,  0] ../source3/lib/dumpcore.c:318(dump_core)
    coredump is handled by helper binary specified at /proc/sys/kernel/core_pattern[2018/04/06 13:43:52.153171,  5]

  client
  ======

  HOST:   Ubuntu 18.04RC (2018-04-06), amd64
  samba:  4.7.6+dfsg~ubuntu-0ubuntu1
  krb5:   1.16-2build1
  sssd:   1.16.0-5ubuntu2

  This is a blocker for us to upgrade from 16.04 to 18.04 after release. :-(

To manage notifications about this bug go to:
https://bugs.launchpad.net/samba/+bug/1761737/+subscriptions