linux-kernel - [PATCH 3/3] serial: qcom-geni: fix garbage output after buffer flush

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]

Date: Mon, 24 Jun 2024 15:31:35 +0200
From: Johan Hovold <johan+linaro@...nel.org>
To: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jirislaby@...nel.org>
Cc: Konrad Dybcio <konrad.dybcio@...aro.org>,
	Douglas Anderson <dianders@...omium.org>,
	Bjorn Andersson <andersson@...nel.org>,
	linux-arm-msm@...r.kernel.org,
	linux-serial@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Johan Hovold <johan+linaro@...nel.org>,
	stable@...r.kernel.org
Subject: [PATCH 3/3] serial: qcom-geni: fix garbage output after buffer flush

The Qualcomm GENI serial driver does not handle buffer flushing and
outputs garbage (or NUL) characters for the remainder of any active TX
command after the write buffer has been cleared.

Implement the flush_buffer() callback and use it to cancel any active TX
command when the write buffer has been emptied.

Fixes: a1fee899e5be ("tty: serial: qcom_geni_serial: Fix softlock")
Cc: stable@...r.kernel.org	# 5.0
Reported-by: Douglas Anderson <dianders@...omium.org>
Signed-off-by: Johan Hovold <johan+linaro@...nel.org>
---
 drivers/tty/serial/qcom_geni_serial.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index 72addeb9f461..5fbb72f1c0c7 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -1084,6 +1084,11 @@ static void qcom_geni_serial_shutdown(struct uart_port *uport)
 	qcom_geni_serial_clear_tx_fifo(uport);
 }
 
+static void qcom_geni_serial_flush_buffer(struct uart_port *uport)
+{
+	qcom_geni_serial_clear_tx_fifo(uport);
+}
+
 static int qcom_geni_serial_port_setup(struct uart_port *uport)
 {
 	struct qcom_geni_serial_port *port = to_dev_port(uport);
@@ -1540,6 +1545,7 @@ static const struct uart_ops qcom_geni_console_pops = {
 	.request_port = qcom_geni_serial_request_port,
 	.config_port = qcom_geni_serial_config_port,
 	.shutdown = qcom_geni_serial_shutdown,
+	.flush_buffer = qcom_geni_serial_flush_buffer,
 	.type = qcom_geni_serial_get_type,
 	.set_mctrl = qcom_geni_serial_set_mctrl,
 	.get_mctrl = qcom_geni_serial_get_mctrl,
-- 
2.44.1