autobuild[sn-devel-144]: intermittent test failure detected

[autobuild]

The autobuild test system (on sn-devel-144) has detected an intermittent failing test in 
the current master tree.

The autobuild log of the failure is available here:

   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-06-14-0027/flakey.log

The failure seems to be in the "samba" suite, whose build logs are available here:

   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-06-14-0027/samba.stderr
   https://git.samba.org/autobuild.flakey.sn-devel-144/2018-06-14-0027/samba.stdout
  
The top commit at the time of the failure was:

commit d33c355103406ceb4941a479f34ea33eae8e87a7
Author: Swen Schillig <swen at vnet.ibm.com>
Date:   Fri May 25 12:45:35 2018 +0200

    CID 1416475: possibly dereferencing NULL in fruit_pread_meta
    
    Signed-off-by: Swen Schillig <swen at vnet.ibm.com>
    Reviewed-by: Christof Schmitt <cs at samba.org>
    Reviewed-by: Ralph Boehme <slow at samba.org>
    
    Autobuild-User(master): Ralph Böhme <slow at samba.org>
    Autobuild-Date(master): Wed Jun 13 16:29:48 CEST 2018 on sn-devel-144

and the last 50 lines of the stdout log were:

[70(148)/855 at 4m19s] samba3.blackbox.smbclient_ntlm.plain (maptoguest)(maptoguest)
[71(161)/855 at 4m20s] samba3.raw.samba3hide(simpleserver)
[72(162)/855 at 4m21s] samba3.raw.samba3checkfsp(simpleserver)
[73(163)/855 at 4m21s] samba3.raw.samba3closeerr(simpleserver)
[74(164)/855 at 4m21s] samba3.smb2.change_notify_disabled(simpleserver)
[75(165)/855 at 4m21s] samba3.smb2.dosmode(simpleserver)
[76(166)/855 at 4m21s] samba3.rpc.schannel_anon_setpw anonymous password set (schannel enforced server-side)(nt4_dc_schannel)
[77(167)/855 at 4m21s] idmap.rfc2307(ad_member_rfc2307)
[78(326)/855 at 5m4s] idmap.alloc(ad_member_rfc2307)
[79(328)/855 at 5m5s] samba3.rpc.lsa.lookupsids krb5 with old ccache ncacn_np with [smb2] (ktest)
[80(329)/855 at 5m5s] samba3.rpc.lsa.lookupsids krb5 ncacn_np with [smb2] (ktest)
[81(330)/855 at 5m5s] samba3.blackbox.rpcclient krb5 ncacn_np with [krb5] (ktest:local)
[82(331)/855 at 5m5s] samba3.blackbox.rpcclient krb5 ncacn_np with [spnego,krb5] (ktest:local)
[83(332)/855 at 5m5s] samba3.rpc.lsa.lookupsids krb5 with old ccache ncacn_np with [smb2,connect] (ktest)
[84(333)/855 at 5m5s] samba3.rpc.lsa.lookupsids krb5 ncacn_np with [smb2,connect] (ktest)
[85(334)/855 at 5m6s] samba3.blackbox.rpcclient krb5 ncacn_np with [krb5,connect] (ktest:local)
[86(335)/855 at 5m6s] samba3.blackbox.rpcclient krb5 ncacn_np with [spnego,krb5,connect] (ktest:local)
[87(336)/855 at 5m6s] samba3.rpc.lsa.lookupsids krb5 with old ccache ncacn_np with [smb2,packet] (ktest)
[88(337)/855 at 5m6s] samba3.rpc.lsa.lookupsids krb5 ncacn_np with [smb2,packet] (ktest)
[89(338)/855 at 5m6s] samba3.blackbox.rpcclient krb5 ncacn_np with [krb5,packet] (ktest:local)
[90(339)/855 at 5m6s] samba3.blackbox.rpcclient krb5 ncacn_np with [spnego,krb5,packet] (ktest:local)
[91(340)/855 at 5m7s] samba3.rpc.lsa.lookupsids krb5 with old ccache ncacn_np with [smb2,sign] (ktest)
[92(341)/855 at 5m7s] samba3.rpc.lsa.lookupsids krb5 ncacn_np with [smb2,sign] (ktest)
[93(342)/855 at 5m7s] samba3.blackbox.rpcclient krb5 ncacn_np with [krb5,sign] (ktest:local)
[94(343)/855 at 5m7s] samba3.blackbox.rpcclient krb5 ncacn_np with [spnego,krb5,sign] (ktest:local)
[95(344)/855 at 5m7s] samba3.rpc.lsa.lookupsids krb5 with old ccache ncacn_np with [smb2,seal] (ktest)
[96(345)/855 at 5m7s] samba3.rpc.lsa.lookupsids krb5 ncacn_np with [smb2,seal] (ktest)
[97(346)/855 at 5m7s] samba3.blackbox.rpcclient krb5 ncacn_np with [krb5,seal] (ktest:local)
[98(347)/855 at 5m8s] samba3.blackbox.rpcclient krb5 ncacn_np with [spnego,krb5,seal] (ktest:local)
[99(348)/855 at 5m8s] samba3.blackbox.sharesec(simpleserver:local)
[100(383)/855 at 5m9s] samba3.blackbox.net_tdb(simpleserver:local)
UNEXPECTED(failure): samba3.blackbox.net_tdb.Looking for open file in locking.tdb(simpleserver:local)
REASON: Exception: Exception: Invalid length of key

FAILED (1 failures, 0 errors and 0 unexpected successes in 0 testsuites)

A summary with detailed information can be found in:
  ./bin/ab/summary
TOP 10 slowest tests
samba3.smbtorture_s3.vfs_aio_fork(simpleserver).RW2(simpleserver) -> 137
idmap.rfc2307(ad_member_rfc2307) -> 34
samba3.smbtorture_s3.plain(ad_dc_ntvfs).LOCK1(ad_dc_ntvfs) -> 12
samba3.smbtorture_s3.plain(ad_dc_ntvfs).IOCTL(ad_dc_ntvfs) -> 6
samba3.smbtorture_s3.plain(ad_dc_ntvfs).TRANS2(ad_dc_ntvfs) -> 6
samba3.smbtorture_s3.vfs_aio_fork(simpleserver).RW1(simpleserver) -> 6
samba3.smbtorture_s3.plain(ad_dc_ntvfs).OPLOCK1(ad_dc_ntvfs) -> 3
samba.tests.messaging.python3(ad_dc_ntvfs:local) -> 2
samba3.blackbox.sharesec(simpleserver:local) -> 2
samba3.smbtorture_s3.vfs_aio_pthread(simpleserver).RW2(simpleserver) -> 2
ERROR: test failed with exit code 1