Bug#920641: cifs: Reading files from samba share with "smb encrypt = mandatory" hangs Applications

[Lukas Straub <lukasstraub2@web.de>]

Source: linux
Version: 4.19.0-1-amd64
Severity: important

Dear Maintainer,
Reading from a cifs share "smb encrypt = mandatory" hangs the Application, however ls and writing files works without porblem.
I dont have these Problems with linux 4.18.0-3.

Steps to reproduce:

1. Setup an samba server with a share similar to the following:
[data]  
        smb encrypt = mandatory
        path = /mnt/data
        available = yes
        read only = no
        inherit permissions = yes
        mangled names = no

2. Mount from the client:
$ mount -t cifs //<server>/data /mnt/nas

3. Read something:
cat /mnt/nas/somefile.txt

The cat then hangs instead of displaying the file.

-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (990, 'testing')
Architecture: amd64 (x86_64)

Kernel: Linux 4.19.0-1-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled