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From: Alexey Dobriyan <adobriyan@gmail.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>
Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: stack leak via uart_get_info() ?
Date: Thu, 5 Oct 2023 19:34:21 +0300	[thread overview]
Message-ID: <967b9ef1-fb36-48bf-9e6a-1b99af24c052@p183> (raw)

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.

Can it trigger while sysfs read is executing?


Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---

--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -775,6 +775,8 @@ static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo)
 	struct uart_port *uport;
 	int ret = -ENODEV;
 
+	*retinfo = (struct serial_struct){};
+
 	/*
 	 * Ensure the state we copy is consistent and no hardware changes
 	 * occur as we go

             reply	other threads:[~2023-10-05 16:42 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-05 16:34 Alexey Dobriyan [this message]
2023-10-05 17:55 ` Greg Kroah-Hartman
2023-10-05 18:44   ` Alexey Dobriyan

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