From: Alexey Dobriyan <adobriyan@gmail.com>
Date: Thu, 5 Oct 2023 16:34:21 +0000 (+0300)
Subject: serial: initialize retinfo in uart_get_info()
X-Git-Tag: v6.7-rc1~75^2~59
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=cfb5e0cece70b36bacbe8f888c096e6370a9c6ba;p=thirdparty%2Flinux.git

serial: initialize retinfo in uart_get_info()

If this check ever triggers

	static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
	{

		uport = uart_port_check(state);
	        if (!uport)
	                goto out;

then all those sysfs users will print stack contents to userspace.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Link: https://lore.kernel.org/r/967b9ef1-fb36-48bf-9e6a-1b99af24c052@p183
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 70bf2bec875c5..be74d30cfa9e7 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -775,6 +775,9 @@ static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
 	struct uart_port *uport;
 	int ret = -ENODEV;
 
+	/* Initialize structure in case we error out later to prevent any stack info leakage. */
+	*retinfo = (struct serial_struct){};
+
 	/*
 	 * Ensure the state we copy is consistent and no hardware changes
 	 * occur as we go