On Tue, Jan 14, 2025 at 10:47:33AM +0100, Johan Hovold wrote: > On Mon, Jan 13, 2025 at 06:00:34PM +0000, Qasim Ijaz wrote: > > 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@xxxxxxxxxxxxxxxxxxxxxxxxx> > > Closes: https://syzkaller.appspot.com/bug?extid=506479ebf12fe435d01a > > Fixes: f7a33e608d9a ("USB: serial: add quatech2 usb to serial driver") > > Cc: <stable@xxxxxxxxxxxxxxx> # 3.5 > > Signed-off-by: Qasim Ijaz <qasdev00@xxxxxxxxx> > > --- > > Thanks for the update. I've applied the patch now after adding Greg's > Reviewed-by tag (for v2). > > For your future contributions, try to remember to include any > Reviewed-by or Tested-by tags when updating the patch unless the changes > are non-trivial. > > There should typically also be a short change log here under the --- > line to indicate what changes from previous versions. > > It is also encouraged to write the commit message in imperative mood > (add, change, fix) and to avoid the phrase "this patch". There are some > more details in > > Documentation/process/submitting-patches.rst > > Something to keep in mind for the future, but this patch already looks > really good. > > Johan Hi Johan, Thanks for reviewing and applying the patch. I appreciate the guidance on patch style and process, and I'll incorporate your suggestions in future submissions. Best regards, Qasim