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From: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
To: linux-bluetooth@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	Marcel Holtmann <marcel@holtmann.org>,
	Johan Hedberg <johan.hedberg@gmail.com>,
	Luiz Augusto von Dentz <luiz.dentz@gmail.com>,
	Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Subject: [PATCH] Bluetooth: hci_ldisc: require CAP_NET_ADMIN to attach N_HCI ldisc
Date: Wed, 22 Sep 2021 08:56:56 -0300	[thread overview]
Message-ID: <20210922115656.97723-1-cascardo@canonical.com> (raw)

Any unprivileged user can attach N_HCI ldisc and send packets coming from a
virtual controller by using PTYs.

Require initial namespace CAP_NET_ADMIN to do that.

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
---
 drivers/bluetooth/hci_ldisc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 5ed2cfa7da1d..5e32e4d5367a 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -479,6 +479,9 @@ static int hci_uart_tty_open(struct tty_struct *tty)
 
 	BT_DBG("tty %p", tty);
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	/* Error if the tty has no write op instead of leaving an exploitable
 	 * hole
 	 */
-- 
2.30.2


             reply	other threads:[~2021-09-22 11:58 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-22 11:56 Thadeu Lima de Souza Cascardo [this message]
2021-09-22 13:26 ` Bluetooth: hci_ldisc: require CAP_NET_ADMIN to attach N_HCI ldisc bluez.test.bot
2021-09-22 14:15 ` [PATCH] " Marcel Holtmann

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