Merge ~ahasenack/ubuntu/+source/samba:samba-kerberos-method-crash-1761737 into ubuntu/+source/samba:ubuntu/devel

[Andreas Hasenack]

  * debian/patches/passdb_dont_return_ok_if_pinfo_not_filled.patch:
    [PATCH] s3:passdb: Do not return OK if we don't have pinfo filled.
    Thanks to Andreas Schneider <email address hidden>. (LP: #1761737)

This fixes a crash in samba when "kerberos method" is set to "secrets and keytab" and the machine was not joined to an active directory domain with "net ads join".

To reproduce the crash:
sudo apt install samba smbclient
# create this /etc/samba/smb.conf:
[global]
 dns proxy = No
 domain master = No
 kerberos method = secrets and keytab
 local master = No
 log file = /var/log/samba/log.%m
 map to guest = Bad User
 max log size = 1000
 obey pam restrictions = Yes
 pam password change = Yes
 panic action = /usr/share/samba/panic-action %d
 passwd chat = *Enter\snew\s*\spassword:* %n\n *Retype\snew\s*\spassword:* %n\n *password\supdated\ssuccessfully* .
 passwd program = /usr/bin/passwd %u
 security = USER
 server role = standalone server
 server string = %h %a
 syslog = 0
 unix password sync = Yes
 usershare allow guests = Yes
 idmap config * : backend = tdb

# restart samba
sudo systemctl restart smbd nmbd

# try to get a share list. It will fail with an error, and a stack trace will be in the samba logs:
$ smbclient -L localhost -N
protocol negotiation failed: NT_STATUS_CONNECTION_DISCONNECTED

/var/log/samba/log.127.0.0.1 will contain a strack trace

PPA with fixed packages:
sudo add-apt-repository -y -u ppa:ahasenack/samba-kerberos-method-1761737

I haven't checked yet if artful and older are affected, the reporter says no. I also think only 4.7.x is affected, so that means bionic only.

[Christian Ehrhardt  (paelzer)]

Patch review - ok
Format/Changelog - ok
Upgrading to new version - ok
Test the fixed issue - ok (verified trigger and fix via ppa)

Versions/Bug tracking - Given the timing you might need to change this to be an early SRU.
I checked with the release Team for another change this morning (but the same is true for all packages for a few days already - a.k.a since the MP is up).

TL;DR:
...
it would need to be a targeted fix in order to be accepted
if it's anything that looks non-trivial upon code inspection by a release team member, it'll likely get kicked back; you can always upload it and try, though
...

So we can go,as is today and rewrite it to be an SRU if rejected by the release Team.
A ping after the upload would be good thou.
Speaking of uploads please ping me if you need help sponsoring or want tags pushed.

review: Approve

[Christian Ehrhardt  (paelzer)]

After discussion on IRC pushed as-is - will be modified to be an SRU instead if requested by the release Team.

Tag creation seems affected by a new incarnation of bug 1687940.
Sponsored as discussed for now.

diff --git a/debian/changelog b/debian/changelog
index abc3310..bf75b4e 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+samba (2:4.7.6+dfsg~ubuntu-0ubuntu2) bionic; urgency=medium
+
+  * debian/patches/passdb_dont_return_ok_if_pinfo_not_filled.patch:
+    [PATCH] s3:passdb: Do not return OK if we don't have pinfo filled.
+    Thanks to Andreas Schneider <[e-mail]>. (LP: #1761737)
+
+ -- Andreas Hasenack <[e-mail]>  Wed, 18 Apr 2018 11:49:55 -0300
+
 samba (2:4.7.6+dfsg~ubuntu-0ubuntu1) bionic; urgency=medium
 
   * New upstream version:
diff --git a/debian/patches/passdb_dont_return_ok_if_pinfo_not_filled.patch b/debian/patches/passdb_dont_return_ok_if_pinfo_not_filled.patch
new file mode 100644
index 0000000..d4ac1bf
--- /dev/null
+++ b/debian/patches/passdb_dont_return_ok_if_pinfo_not_filled.patch
@@ -0,0 +1,36 @@
+From 8fb23665ddad8f65a6461c310ed5680d104fd9bf Mon Sep 17 00:00:00 2001
+From: Andreas Schneider <[e-mail]>
+Date: Tue, 17 Apr 2018 08:55:23 +0200
+Subject: [PATCH] s3:passdb: Do not return OK if we don't have pinfo set up
+
+This prevents a crash in fill_mem_keytab_from_secrets()
+
+BUG: https://bugzilla.samba.org/show_bug.cgi?id=13376
+
+Signed-off-by: Andreas Schneider <[e-mail]>
+Reviewed-by: Stefan Metzmacher <[e-mail]>
+
+(cherry picked from commit 99859479fc6e12b2f74ce2dfa83da56d8b8f3d26)
+Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/samba/+bug/1761737
+Origin: https://attachments.samba.org/attachment.cgi?id=14159
+Last-Update: 2018-04-19
+---
+ source3/passdb/machine_account_secrets.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/source3/passdb/machine_account_secrets.c b/source3/passdb/machine_account_secrets.c
+index 75f31cb04e2..d36fa268a4b 100644
+--- a/source3/passdb/machine_account_secrets.c
++++ b/source3/passdb/machine_account_secrets.c
+@@ -1317,7 +1317,7 @@ NTSTATUS secrets_fetch_or_upgrade_domain_info(const char *domain,
+ 
+ 	last_set_time = secrets_fetch_pass_last_set_time(domain);
+ 	if (last_set_time == 0) {
+-		return NT_STATUS_OK;
++		return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
+ 	}
+ 	unix_to_nt_time(&last_set_nt, last_set_time);
+ 
+-- 
+2.16.3
+
diff --git a/debian/patches/series b/debian/patches/series
index 37e914d..1aa159c 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -11,3 +11,4 @@ systemd-syslog.target-is-obsolete.patch
 Add-documentation-to-systemd-Unit-files.patch
 fix_kill_path_in_units.patch
 nmbd-requires-a-working-network.patch
+passdb_dont_return_ok_if_pinfo_not_filled.patch