La actualización de apt-get no funciona: errores de firma / verificación

Cuando corro apt-get updateme sale

Ign:1 http://dl.google.com/linux/musicmanager/deb stable InRelease
Ign:2 http://archive-4.kali.org/kali kali-rolling InRelease                
Hit:3 http://archive-4.kali.org/kali-security sana/updates InRelease
0% [3 InRelease gpgv 11.9 kB] [Waiting for headers] [Waiting for headers]Couldn't create tempfiles for splitting up /var/lib/apt/lists/security.kali.org_kali-seErr:3 http://archive-4.kali.org/kali-security sana/updates InRelease     
  Could not execute 'apt-key' to verify signature (is gnupg installed?)
Hit:4 http://archive-4.kali.org/kali sana InRelease                      
0% [4 InRelease gpgv 20.3 kB] [Waiting for headers]Couldn't create tempfiles forErr:4 http://archive-4.kali.org/kali sana InRelease_dists_sana_InRelease
  Could not execute 'apt-key' to verify signature (is gnupg installed?)
Get:5 http://archive-4.kali.org/kali kali-rolling Release [23.7 kB]
Get:6 http://archive-4.kali.org/kali kali-rolling Release.gpg [819 B]          
0% [6 Release.gpg gpgv 23.7 kB]                                    3,846 B/s 0smktemp: failed to create directory via template '/tmp/tmp.XXXXXXXXXX': Permission denied
Err:6 http://archive-4.kali.org/kali kali-rolling Release.gpg                  
  At least one invalid signature was encountered.
Hit:7 http://dl.google.com/linux/musicmanager/deb stable Release               
80% [Release.gpg gpgv 1,345 B]mktemp: failed to create directory via template '/tmp/tmp.XXXXXXXXXX': Permission denied
Err:8 http://dl.google.com/linux/musicmanager/deb stable Release.gpg
  At least one invalid signature was encountered.
Reading package lists... Done 
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive-4.kali.org/kali-security sana/updates InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive-4.kali.org/kali sana InRelease: Could not execute 'apt-key' to verify signature (is gnupg installed?)
W: GPG error: http://archive-4.kali.org/kali kali-rolling Release: At least one invalid signature was encountered.
E: The repository 'http://http.kali.org/kali kali-rolling Release' is no longer signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://dl.google.com/linux/musicmanager/deb stable Release: At least one invalid signature was encountered.

No tengo idea de cómo sucedió esto o cómo solucionarlo. Tengo gnupg, gnupg-agent, gnupg-pkcs11-scd, gnupg2, gnupg-curl, gnupg-pkcs11-scd-dbg instalados.

Borre el caché APT y vuelva a generarlo:

sudo apt-get clean
sudo mv /var/lib/apt/lists /tmp
sudo mkdir -p /var/lib/apt/lists/partial
sudo apt-get clean
sudo apt-get update

Tal vez hay un enlace o archivo no válido en el directorio /etc/apt/trusted.gpg.d/

Compruebe que el directorio contiene archivos y enlaces válidos, por ejemplo:

# ls -L /etc/apt/trusted.gpg.d/* > /dev/null
ls: cannot access '/etc/apt/trusted.gpg.d/live-net-archive-keyring.gpg': No such file or directory

Por lo tanto, busque el paquete que debe contener el archivo

# dpkg -S /etc/apt/trusted.gpg.d/live-net-archive-keyring.gpg
live-net-archive-keyring: /etc/apt/trusted.gpg.d/live-net-archive-keyring.gpg

y tome algunas de las siguientes acciones:

reinstalarlo

# aptitude reinstall live-net-archive-keyring

o reinstalar todos los llaveros instalados

# aptitude reinstall $(dpkg -l '*keyring' | awk '$1 == "ii" {print $2}')
The following packages will be REINSTALLED:
debian-archive-keyring gnome-keyring live-net-archive-keyring siduction-archive-keyring 

o eliminar el enlace o archivo no válido

# rm /etc/apt/trusted.gpg.d/live-net-archive-keyring.gpg 

Tratar chown root:root /tmp chmod 1777 /tmp

Todas mis claves eran correctas, pero la solución de okwap me indicó que buscara en el directorio / tmp.

Tenía miles de subdirectorios allí, creados por un proceso de servicio que tenía problemas para comenzar. Incluso tuve problemas para eliminar todos los directorios porque había muchos (tuve que canalizar ls a xargs para evitar errores de "demasiados argumentos").

Tan pronto como se limpió mi / tmp, apt-get update funcionó bien nuevamente. Entonces sospecho que hay algún código en apt-get update relacionado con la verificación de firmas que usa / tmp y falla cuando hay una cantidad tonta de elementos allí.