From: Adrian Reber areber@redhat.com
[ 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@kernel.org Signed-off-by: Adrian Reber areber@redhat.com Acked-by: Andrei Vagin avagin@gmail.com Link: https://lore.kernel.org/r/20231208143656.1019-1-areber@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1736130f9c39..1c7c3a37099d 100644 --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -786,7 +786,7 @@ 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, @@ -803,7 +803,7 @@ 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,