This is a note to let you know that I've just added the patch titled
tty: allow TIOCSLCKTRMIOS with CAP_CHECKPOINT_RESTORE
to the 6.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tty-allow-tiocslcktrmios-with-cap_checkpoint_restore.patch
and it can be found in the queue-6.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 85655386eaef056ee0c06ea7a0117c3ece7e50f0
Author: Adrian Reber <areber@xxxxxxxxxx>
Date: Fri Dec 8 15:36:56 2023 +0100
tty: allow TIOCSLCKTRMIOS with CAP_CHECKPOINT_RESTORE
[ 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>
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index 4b499301a3db..85de90eebc7b 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -844,7 +844,7 @@ int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
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,
@@ -861,7 +861,7 @@ int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
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,
