| Message ID | 20250113180034.17063-1-qasdev00@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] USB: serial: quatech2: Fix null-ptr-deref in qt2_process_read_urb() | expand |
diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c index a317bdbd00ad..72fe83a6c978 100644 --- a/drivers/usb/serial/quatech2.c +++ b/drivers/usb/serial/quatech2.c @@ -503,7 +503,7 @@ static void qt2_process_read_urb(struct urb *urb) newport = *(ch + 3); - if (newport > serial->num_ports) { + if (newport >= serial->num_ports) { dev_err(&port->dev, "%s - port change to invalid port: %i\n", __func__, newport);
This patch addresses a null-ptr-deref in qt2_process_read_urb() due to an incorrect bounds check in the following: if (newport > serial->num_ports) { dev_err(&port->dev, "%s - port change to invalid port: %i\n", __func__, newport); break; } The condition doesn't account for the valid range of the serial->port buffer, which is from 0 to serial->num_ports - 1. When newport is equal to serial->num_ports, the assignment of "port" in the following code is out-of-bounds and NULL: serial_priv->current_port = newport; port = serial->port[serial_priv->current_port]; The fix checks if newport is greater than or equal to serial->num_ports indicating it is out-of-bounds. Reported-by: syzbot <syzbot+506479ebf12fe435d01a@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=506479ebf12fe435d01a Fixes: f7a33e608d9a ("USB: serial: add quatech2 usb to serial driver") Cc: <stable@vger.kernel.org> # 3.5 Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> --- drivers/usb/serial/quatech2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)