tty: n_gsm: require CAP_NET_ADMIN to attach N_GSM0710 ldisc

commit 67c3775689 upstream.

Any unprivileged user can attach N_GSM0710 ldisc, but it requires
CAP_NET_ADMIN to create a GSM network anyway.

Require initial namespace CAP_NET_ADMIN to do that.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Link: https://lore.kernel.org/r/20230731185942.279611-1-cascardo@canonical.com
Cc: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Thadeu Lima de Souza Cascardo 2023-07-31 15:59:42 -03:00 committed by Greg Kroah-Hartman
parent 6cbbe1ba76
commit 2d154a54c5
1 changed files with 3 additions and 0 deletions

View File

@ -2827,6 +2827,9 @@ static int gsmld_open(struct tty_struct *tty)
{
struct gsm_mux *gsm;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (tty->ops->write == NULL)
return -EINVAL;