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From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
To: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>
Subject: [PATCH] tty: n_gsm: require CAP_NET_ADMIN to attach N_GSM0710 ldisc
Date: Mon, 31 Jul 2023 15:59:42 -0300	[thread overview]
Message-ID: <20230731185942.279611-1-cascardo@canonical.com> (raw)

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>
---
 drivers/tty/n_gsm.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 1cdefac4dd1b..c7a787f10a9c 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -3576,6 +3576,9 @@ 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;
 
-- 
2.34.1


             reply	other threads:[~2023-07-31 19:00 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-31 18:59 Thadeu Lima de Souza Cascardo [this message]
2023-08-01  4:53 ` [PATCH] tty: n_gsm: require CAP_NET_ADMIN to attach N_GSM0710 ldisc Greg Kroah-Hartman
2023-08-01 13:02   ` Thadeu Lima de Souza Cascardo
2023-08-03  7:48     ` Greg Kroah-Hartman
2023-08-03 11:38       ` Thadeu Lima de Souza Cascardo

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