linux-kernel - [PATCH 2/3] USB: serial: cp210x: disable break signalling on CP2105 SCI

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230602124642.19076-3-johan@kernel.org>
Date:   Fri,  2 Jun 2023 14:46:41 +0200
From:   Johan Hovold <johan@...nel.org>
To:     Johan Hovold <johan@...nel.org>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
        Corey Minyard <minyard@....org>
Subject: [PATCH 2/3] USB: serial: cp210x: disable break signalling on CP2105 SCI

Only the first UART interface (ECI) on CP2105 supports break signalling.

Return an error on requests for break state changes for the second
interface (SCI) to avoid transmitting a garbage character and waiting
when break is not supported.

Signed-off-by: Johan Hovold <johan@...nel.org>
---
 drivers/usb/serial/cp210x.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 81e49ed9d147..1e61fe043171 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -1437,8 +1437,14 @@ static int cp210x_tiocmget(struct tty_struct *tty)
 static int cp210x_break_ctl(struct tty_struct *tty, int break_state)
 {
 	struct usb_serial_port *port = tty->driver_data;
+	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
 	u16 state;
 
+	if (priv->partnum == CP210X_PARTNUM_CP2105) {
+		if (cp210x_interface_num(port->serial) == 1)
+			return -ENOTTY;
+	}
+
 	if (break_state == 0)
 		state = BREAK_OFF;
 	else
-- 
2.39.3