commit 26df05a8c1420ad3de314fdd407e7fc2058cc7aa upstream. grub2 has submenus where to use grub-reboot, it requires: grub-reboot X>Y where X is the main index and Y is the submenu. Thus if you have: menuentry 'Debian GNU/Linux' --class debian --class gnu-linux ... [...] } submenu 'Advanced options for Debian GNU/Linux' $menuentry_id_option ... menuentry 'Debian GNU/Linux, with Linux 6.0.0-4-amd64' --class debian --class gnu-linux ... [...] } menuentry 'Debian GNU/Linux, with Linux 6.0.0-4-amd64 (recovery mode)' --class debian --class gnu-linux ... [...] } menuentry 'Debian GNU/Linux, with Linux test' --class debian --class gnu-linux ... [...] } And wanted to boot to the "Linux test" kernel, you need to run: # grub-reboot 1>2 As 1 is the second top menu (the submenu) and 2 is the third of the sub menu entries. Have the grub.cfg parsing for grub2 handle such cases. Cc: stable@vger.kernel.org Fixes: a15ba91361d46 ("ktest: Add support for grub2") Reviewed-by: John 'Warthog9' Hawley (VMware) <warthog9@eaglescrag.net> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>