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Commit 996291d0 authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

mxser: fix xmit_buf leak in activate when LSR == 0xff 



[ Upstream commit cd3a4907ee334b40d7aa880c7ab310b154fd5cd4 ]

When LSR is 0xff in ->activate() (rather unlike), we return an error.
Provided ->shutdown() is not called when ->activate() fails, nothing
actually frees the buffer in this case.

Fix this by properly freeing the buffer in a designated label. We jump
there also from the "!info->type" if now too.

Fixes: 6769140d ("tty: mxser: use the tty_port_open method")
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220124071430.14907-6-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 58200ded

drivers/tty/mxser.c

+11 −4
Original line number Diff line number Diff line
@@ -861,6 +861,7 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty) 
	struct mxser_port *info = container_of(port, struct mxser_port, port);

	unsigned long page;

	unsigned long flags;

	int ret;



	page = __get_free_page(GFP_KERNEL);

	if (!page)
@@ -870,9 +871,9 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty) 


	if (!info->ioaddr || !info->type) {

		set_bit(TTY_IO_ERROR, &tty->flags);

		free_page(page);

		spin_unlock_irqrestore(&info->slock, flags);

		return 0;

		ret = 0;

		goto err_free_xmit;

	}

	info->port.xmit_buf = (unsigned char *) page;
@@ -898,8 +899,10 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty) 
		if (capable(CAP_SYS_ADMIN)) {

			set_bit(TTY_IO_ERROR, &tty->flags);

			return 0;

		} else

			return -ENODEV;

		}



		ret = -ENODEV;

		goto err_free_xmit;

	}



	/*
@@ -944,6 +947,10 @@ static int mxser_activate(struct tty_port *port, struct tty_struct *tty) 
	spin_unlock_irqrestore(&info->slock, flags);



	return 0;

err_free_xmit:

	free_page(page);

	info->port.xmit_buf = NULL;

	return ret;

}



/*