From 1568c58d11a7c851bd09341aeefd6a1c308ac40d Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 17 Jan 2020 10:50:24 +0100 Subject: USB: serial: io_edgeport: add missing active-port sanity check The driver receives the active port number from the device, but never made sure that the port number was valid. This could lead to a NULL-pointer dereference or memory corruption in case a device sends data for an invalid port. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold --- drivers/usb/serial/io_edgeport.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c index 0582d78bdb1d..5737add6a2a4 100644 --- a/drivers/usb/serial/io_edgeport.c +++ b/drivers/usb/serial/io_edgeport.c @@ -1725,7 +1725,8 @@ static void edge_break(struct tty_struct *tty, int break_state) static void process_rcvd_data(struct edgeport_serial *edge_serial, unsigned char *buffer, __u16 bufferLength) { - struct device *dev = &edge_serial->serial->dev->dev; + struct usb_serial *serial = edge_serial->serial; + struct device *dev = &serial->dev->dev; struct usb_serial_port *port; struct edgeport_port *edge_port; __u16 lastBufferLength; @@ -1821,9 +1822,8 @@ static void process_rcvd_data(struct edgeport_serial *edge_serial, /* spit this data back into the tty driver if this port is open */ - if (rxLen) { - port = edge_serial->serial->port[ - edge_serial->rxPort]; + if (rxLen && edge_serial->rxPort < serial->num_ports) { + port = serial->port[edge_serial->rxPort]; edge_port = usb_get_serial_port_data(port); if (edge_port && edge_port->open) { dev_dbg(dev, "%s - Sending %d bytes to TTY for port %d\n", @@ -1833,8 +1833,8 @@ static void process_rcvd_data(struct edgeport_serial *edge_serial, rxLen); edge_port->port->icount.rx += rxLen; } - buffer += rxLen; } + buffer += rxLen; break; case EXPECT_HDR3: /* Expect 3rd byte of status header */ @@ -1869,6 +1869,8 @@ static void process_rcvd_status(struct edgeport_serial *edge_serial, __u8 code = edge_serial->rxStatusCode; /* switch the port pointer to the one being currently talked about */ + if (edge_serial->rxPort >= edge_serial->serial->num_ports) + return; port = edge_serial->serial->port[edge_serial->rxPort]; edge_port = usb_get_serial_port_data(port); if (edge_port == NULL) { -- cgit v1.2.3