samba4: smbclient segmentation fault

[jsalort (Julien Salort)]

I am running MacPorts 2.6.4 on macOS Catalina. samba4 @4.13.1_0 smbclient crashes with segmentation fault:

% smbclient -L PRAXIS
Enter WORKGROUP\jsalort's password: 
zsh: segmentation fault  smbclient -L PRAXIS

[ryandesign (Ryan Carsten Schmidt)]

Attaching the crash log might be helpful.

[jsalort (Julien Salort)]

Crash log

[ryandesign (Ryan Carsten Schmidt)]

I recommend you search the ​samba bug tracker for any reports of this problem. And if you don't find one, file one. And provide the URL here so we can keep track of it.

Ordinarily I would suggest trying the latest version first, however I am unable to update our port to the latest version because it does not build, and I have filed bug reports about that: ​https://bugzilla.samba.org/show_bug.cgi?id=14680, ​https://bugzilla.samba.org/show_bug.cgi?id=14681

[21stcaveman (Hamid Maadani)]

Did some research, found this: ​https://bugzilla.redhat.com/show_bug.cgi?id=1892745

Updated the port to 4.14.7 (​https://github.com/macports/macports-ports/pull/12057) in the hopes that latest stable version would have the fix. I still get the segfault though.

for me, it fails while starting 'GENSEC spengo' with gs_krb5. From debug output:

...
cli_session_creds_prepare_krb5: Successfully authenticated as xxx@yyy (xxx@yyy) to access yyy using Kerberos
cli_session_setup_spnego_send: Connect to yyy as xxx@yyy using SPNEGO
...
Starting GENSEC mechanism spnego
Starting GENSEC submechanism gse_krb5
Segmentation fault: 11

This could be fixed with turning off gse_krb5 and NTLMv2 in previous versions (​https://stackoverflow.com/questions/52034903/smbclient-authentication-file-session-setup-failed-nt-status-invalid-paramet), but is enforced from version 4.13.0 (​https://www.samba.org/samba/docs/current/man-html/smb.conf.5.html#CLIENTUSESPNEGO).

[21stcaveman (Hamid Maadani)]

A downgrade to 4.12.15, combined with

    client NTLMv2 auth = no
    client use spnego = no

in smb.conf, did NOT fix the problem either. Fyi.

[21stcaveman (Hamid Maadani)]

tested newest RC version (4.15.0rc4), issue still persists.
Here is the Backtrace:

PANIC (pid 20652): Signal 11: Segmentation fault: 11 in 4.15.0rc4
BACKTRACE: 21 stack frames:
0   libsamba-util.0.dylib               0x00000001041bc4f2 log_stack_trace + 52
1   libsamba-util.0.dylib               0x00000001041bc5c1 smb_panic + 14
2   libsamba-util.0.dylib               0x00000001041bc7d8 BlockSignals + 0
3   libsamba-util.0.dylib               0x00000001041bc35b smb_panic_log + 0
4   libsystem_platform.dylib            0x00007fff205b4d7d _sigtramp + 29
5   ???                                 0x00000000000002b0 0x0 + 688
6   libgssapi-samba4.2.dylib            0x00000001048257dd gss_oid_equal + 50
7   libgssapi-samba4.2.dylib            0x0000000104823022 __gss_get_mechanism + 39
8   libgssapi-samba4.2.dylib            0x000000010482568f gss_init_sec_context + 326
9   libgse-samba4.dylib                 0x00000001040fc4c0 gensec_gse_update_send + 378
10  libgensec-samba4.dylib              0x00000001040b57d3 gensec_update_send + 263
11  libgensec-samba4.dylib              0x00000001040a7ce1 gensec_spnego_update_send + 1419
12  libgensec-samba4.dylib              0x00000001040b57d3 gensec_update_send + 263
13  liblibsmb-samba4.dylib              0x0000000103df09ff cli_session_setup_gensec_local_next + 94
14  liblibsmb-samba4.dylib              0x0000000103ded8b4 cli_session_setup_creds_send + 1528
15  liblibsmb-samba4.dylib              0x0000000103dee16a cli_session_setup_creds + 105
16  liblibsmb-samba4.dylib              0x0000000103e0cb68 do_connect + 382
17  liblibsmb-samba4.dylib              0x0000000103e0b6cc cli_cm_connect + 72
18  liblibsmb-samba4.dylib              0x0000000103e0b597 cli_cm_open + 123
19  smbclient                           0x00000001037dcce5 main + 3333
20  libdyld.dylib                       0x00007fff2058af5d start + 1

@ryandesign , can you please file a bug report with samba? my account has expired.