USB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb()

Summary

In the Linux kernel, the following vulnerability has been resolved: USB: serial: quatech2: fix null-ptr-deref in qt2_process_read_urb() 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.

Timeline

1. Feb 10, 2025, 3:58 PM UTCCVE published
2. Oct 1, 2025, 7:51 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. May 11, 2026, 9:04 PM UTCRecord last updated

Affected versions

• Linux Linux

  Version range not reported

• Linux Linux

  3.5

References 8