From: Adrian Reber <areber@xxxxxxxxxx> [ Upstream commit e0f25b8992345aa5f113da2815f5add98738c611 ] The capability CAP_CHECKPOINT_RESTORE was introduced to allow non-root users to checkpoint and restore processes as non-root with CRIU. This change extends CAP_CHECKPOINT_RESTORE to enable the CRIU option '--shell-job' as non-root. CRIU's man-page describes the '--shell-job' option like this: Allow one to dump shell jobs. This implies the restored task will inherit session and process group ID from the criu itself. This option also allows to migrate a single external tty connection, to migrate applications like top. TIOCSLCKTRMIOS can only be done if the process has CAP_SYS_ADMIN and this change extends it to CAP_SYS_ADMIN or CAP_CHECKPOINT_RESTORE. With this change it is possible to checkpoint and restore processes which have a tty connection as non-root if CAP_CHECKPOINT_RESTORE is set. Acked-by: Christian Brauner <brauner@xxxxxxxxxx> Signed-off-by: Adrian Reber <areber@xxxxxxxxxx> Acked-by: Andrei Vagin <avagin@xxxxxxxxx> Link: https://lore.kernel.org/r/20231208143656.1019-1-areber@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/tty/tty_ioctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c index 68b07250dcb6..134f07c2431e 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -763,7 +763,7 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, ret = -EFAULT; return ret; case TIOCSLCKTRMIOS: - if (!capable(CAP_SYS_ADMIN)) + if (!checkpoint_restore_ns_capable(&init_user_ns)) return -EPERM; copy_termios_locked(real_tty, &kterm); if (user_termios_to_kernel_termios(&kterm, @@ -780,7 +780,7 @@ int tty_mode_ioctl(struct tty_struct *tty, struct file *file, ret = -EFAULT; return ret; case TIOCSLCKTRMIOS: - if (!capable(CAP_SYS_ADMIN)) + if (!checkpoint_restore_ns_capable(&init_user_ns)) return -EPERM; copy_termios_locked(real_tty, &kterm); if (user_termios_to_kernel_termios_1(&kterm, -- 2.43.0
