[Pkg-samba-maint] Bug#1063755: after upgrading to booksworm samba stopped working with autofs in ghost mode

[Barchan barchan]

Package: samba
Version: 2:4.17.12+dfsg-0+deb12u1
Severity: normal
Tags: upstream
X-Debbugs-Cc: barchan75 at gmail.com

Dear Maintainer,

After upgrading Debian from version 11 to 12, we have observed
incorrect behavior of our mechanism for sharing logs from filesystems
mounted using autofs through Samba.

The autofs configuration appears as follows:

File /etc/auto.master:
/mnt/linbkp1 /etc/autofs.linbkp1 --timeout=60,--ghost

File /etc/autofs.linbkp1:
dd     -fstype=nfs,ro, linbkp1:/mnt/dd

Autofs itself works well - when the resource is not mounted, accessing
the directory from shell triggers its mounting.

The /mnt directory is shared in Samba in the standard way:

[mnt]
  path = /mnt
  browseable = yes
  read only = yes
  force user = root
  guest ok = no

(the rest of the smb.conf is the default debian configuration)

When access to the directory is initiated from a Linux system and the
resource is still mounted, the shared directory works correctly.

However, if the resource expires and is unmounted from the filesystem,
Samba version 4.17.12 fails to access the resource.

Attempting to list the resource results in an error:

smb: \linbkp1\dd\> ls
NT_STATUS_OBJECT_NAME_NOT_FOUND listing \linbkp1\dd\*

In Debian 11, where Samba 4.13.13 was used, a similar operation would
mount the resource, and if not on the first attempt, then subsequent
attempts to list the contents of the directory would display them
correctly. This mechanism also worked in older versions of Samba (from
Debian 9 and Debian 10).

I also tested Samba in debian-backports (samba 4.19.4) and
debian-experimental (samba 4.20.0~rc1), as well as with Red Hat 9
(Samba 4.18.6), and the error still persists.

Bug is reported upstream with the same content as
https://bugzilla.samba.org/show_bug.cgi?id=15578

-- Package-specific info:
* /etc/samba/smb.conf present, and attached
* /var/lib/samba/dhcp.conf not present

-- System Information:
Debian Release: 12.5
 APT prefers stable-updates
 APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500,
'proposed-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 6.1.0-18-amd64 (SMP w/1 CPU thread; PREEMPT)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages samba depends on:
ii  init-system-helpers  1.65.2
ii  libbsd0              0.11.7-2
ii  libc6                2.36-9+deb12u4
ii  libcups2             2.4.2-3+deb12u5
ii  libgnutls30          3.7.9-2+deb12u2
ii  libldap-2.5-0        2.5.13+dfsg-5
ii  libldb2              2:2.6.2+samba4.17.12+dfsg-0+deb12u1
ii  libpam-modules       1.5.2-6+deb12u1
ii  libpam-runtime       1.5.2-6+deb12u1
ii  libpopt0             1.19+dfsg-1
ii  libtalloc2           2.4.0-f2
ii  libtasn1-6           4.19.0-2
ii  libtdb1              1.4.8-2
ii  libtevent0           0.14.1-1
ii  passwd               1:4.13+dfsg1-1+b1
ii  procps               2:4.0.2-3
ii  python3              3.11.2-1+b1
ii  python3-dnspython    2.3.0-1
ii  python3-samba        2:4.17.12+dfsg-0+deb12u1
ii  samba-common         2:4.17.12+dfsg-0+deb12u1
ii  samba-common-bin     2:4.17.12+dfsg-0+deb12u1
ii  samba-libs           2:4.17.12+dfsg-0+deb12u1
ii  tdb-tools            1.4.8-2

Versions of packages samba recommends:
ii  attr                1:2.5.1-4
ii  logrotate           3.21.0-1
ii  python3-markdown    3.4.1-2
ii  samba-ad-provision  2:4.17.12+dfsg-0+deb12u1
ii  samba-dsdb-modules  2:4.17.12+dfsg-0+deb12u1
ii  samba-vfs-modules   2:4.17.12+dfsg-0+deb12u1

Versions of packages samba suggests:
pn  bind9         <none>
pn  bind9utils    <none>
pn  ctdb          <none>
pn  ldb-tools     <none>
pn  ntp | chrony  <none>
pn  ufw           <none>
pn  winbind       <none>

-- no debconf information