Allow kdump.service to access LUKS volume keys

Resoles: https://issues.redhat.com/browse/RHEL-124989

Currently kdump.service fails to read LUKS volume keys,

    kdumpctl[4001]: Nothing to read on input.
    kdumpctl[3624]: kdump: Error: Could not unlock the LUKS device.
    kdumpctl[3624]: kdump: Failed to get logon key kdump-cryptsetup:vk-eed43d84-d79f-4b6d-8159-c859bb1915ee. Run 'kdumpctl restart' manually to start kdump.
    kdumpctl[3624]: kdump: kexec: failed to prepare for a LUKS target
    kdumpctl[3624]: kdump: Starting kdump: [FAILED]
    systemd[1]: kdump.service: Main process exited, code=exited, status=1/FAILURE
    systemd[1]: kdump.service: Failed with result 'exit-code'.
    systemd[1]: Failed to start kdump.service - Crash recovery kernel arming.

Use KeyringMode=shared to link the user keyring of root to the session
keyring so kdump.service can access the LUKS volume keys stored in
root's user keyring. For more details on KeyringMode, man systemd.exec.

Fixes: d9677e1 ("Support dumping to a LUKS-encrypted target")
Signed-off-by: Coiby Xu <[email protected]>

Author: coiby

kdump.service

@@ -11,6 +11,7 @@ ExecStop=/usr/bin/kdumpctl stop
 ExecReload=/usr/bin/kdumpctl reload
 RemainAfterExit=yes
 StartLimitInterval=0
+KeyringMode=shared
 
 [Install]
 WantedBy=multi-user.target