[Pkg-samba-maint] Bug#954935: winbind crashes when queried for user

[Andreas Pflug]

Package: winbind
Version: 2:4.9.5+dfsg-5+deb10u1

I have Samba running with LDAP backend. Machine was installed freshly
with latest Buster, config copied and adapted from an old installation.

When running wbinfo -g, groups are listed as expected.
When running wbinfo -u, the winbind process crashes in
fill_domain_username_talloc, leaving the trace below with loglevel 10.

I found this
https://gitlab.com/samba-team/devel/samba/commit/1b39c563546aed677d0ac99b9fb8b44a5b48c1e4
when googling for my problem, might be related or not.


[2020/03/25 11:00:24.946837, 10, pid=5567, effective(0, 0), real(0, 0),
class=winbind]
../source3/winbindd/wb_query_user_list.c:77(wb_query_user_lis$
  dcerpc_wbint_QueryUserList returned 201 users
[2020/03/25 11:00:25.157159,  0] ../lib/util/fault.c:79(fault_report)
  ===============================================================
[2020/03/25 11:00:25.157170,  0] ../lib/util/fault.c:80(fault_report)
  INTERNAL ERROR: Signal 11 in pid 5567 (4.9.5-Debian)
  Please read the Trouble-Shooting section of the Samba HOWTO
[2020/03/25 11:00:25.157178,  0] ../lib/util/fault.c:82(fault_report)
  ===============================================================
[2020/03/25 11:00:25.157183,  0] ../source3/lib/util.c:816(smb_panic_s3)
  PANIC (pid 5567): internal error
[2020/03/25 11:00:25.157541,  0] ../lib/util/fault.c:261(log_stack_trace)
  BACKTRACE: 21 stack frames:
   #0 /lib/x86_64-linux-gnu/libsamba-util.so.0(log_stack_trace+0x32)
[0x7f8ee09fb8d2]
   #1 /lib/x86_64-linux-gnu/libsmbconf.so.0(smb_panic_s3+0x20)
[0x7f8ee00351c0]
   #2 /lib/x86_64-linux-gnu/libsamba-util.so.0(smb_panic+0x2f)
[0x7f8ee09fb9df]
   #3 /lib/x86_64-linux-gnu/libsamba-util.so.0(+0x24c16) [0x7f8ee09fbc16]
   #4 /lib/x86_64-linux-gnu/libpthread.so.0(+0x12730) [0x7f8ee0d08730]
   #5
/usr/lib/x86_64-linux-gnu/samba/libsamba3-util.so.0(strlower_m+0x11)
[0x7f8edff8f5a1]
   #6 /usr/sbin/winbindd(fill_domain_username_talloc+0x36) [0x5641735a4486]
   #7 /usr/sbin/winbindd(+0x68b4e) [0x5641735dcb4e]
   #8 /lib/x86_64-linux-gnu/libdcerpc-binding.so.0(+0x16431)
[0x7f8ee0a6f431]
   #9 /usr/sbin/winbindd(+0x5970d) [0x5641735cd70d]
   #10 /usr/sbin/winbindd(+0x571ac) [0x5641735cb1ac]
   #11 /usr/sbin/winbindd(+0x552dd) [0x5641735c92dd]
   #12 /usr/sbin/winbindd(+0x81867) [0x5641735f5867]
   #13 /usr/sbin/winbindd(+0x810e6) [0x5641735f50e6]
   #14
/lib/x86_64-linux-gnu/libtevent.so.0(tevent_common_invoke_fd_handler+0x7f)
[0x7f8edfdc603f]
   #15 /lib/x86_64-linux-gnu/libtevent.so.0(+0xd05f) [0x7f8edfdcc05f]
   #16 /lib/x86_64-linux-gnu/libtevent.so.0(+0xb2d7) [0x7f8edfdca2d7]
   #17 /lib/x86_64-linux-gnu/libtevent.so.0(_tevent_loop_once+0x84)
[0x7f8edfdc57e4]
   #18 /usr/sbin/winbindd(main+0xdc4) [0x56417359bc44]
   #19 /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xeb)
[0x7f8edfc2209b]
   #20 /usr/sbin/winbindd(_start+0x2a) [0x56417359c1fa]
[2020/03/25 11:00:25.157594,  0] ../source3/lib/util.c:828(smb_panic_s3)
  smb_panic(): calling panic action [/usr/share/samba/panic-action 5567]
[2020/03/25 11:00:25.159620,  0] ../source3/lib/util.c:836(smb_panic_s3)
  smb_panic(): action returned status 0
[2020/03/25 11:00:25.159640,  0] ../source3/lib/dumpcore.c:315(dump_core)