| Message ID | Z4LP0VsyOkaRBQL9@qasdev.system (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb: Fix null-ptr-deref in qt2_process_read_urb() | expand |
On Sat, Jan 11, 2025 at 08:08:49PM +0000, qasdev 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@syzkaller.appspotmail.com> > Closes: https://syzkaller.appspot.com/bug?extid=506479ebf12fe435d01a > Tested-by: syzbot <syzbot+506479ebf12fe435d01a@syzkaller.appspotmail.com> > Tested-by: Qasim Ijaz <qasdev00@gmail.com> > Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> Your signed-off-by does not match your "From:" line :( Also, no need to add a tested-by when you sign off on your own patch, that is usually implied. thanks, greg k-h
On Sun, Jan 12, 2025 at 09:42:45AM +0100, Greg Kroah-Hartman wrote: > On Sat, Jan 11, 2025 at 08:08:49PM +0000, qasdev 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@syzkaller.appspotmail.com> > > Closes: https://syzkaller.appspot.com/bug?extid=506479ebf12fe435d01a > > Tested-by: syzbot <syzbot+506479ebf12fe435d01a@syzkaller.appspotmail.com> > > Tested-by: Qasim Ijaz <qasdev00@gmail.com> > > Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> > > Your signed-off-by does not match your "From:" line :( > > Also, no need to add a tested-by when you sign off on your own patch, > that is usually implied. > > thanks, > > greg k-h Hi Greg, Thank you for your feedback on my patch. I’ve sent a v2 patch in a new thread, addressing the issues with the From: line and removing the redundant Tested-by tag. Best regards, Qasim
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 Tested-by: syzbot <syzbot+506479ebf12fe435d01a@syzkaller.appspotmail.com> Tested-by: Qasim Ijaz <qasdev00@gmail.com> Signed-off-by: Qasim Ijaz <qasdev00@gmail.com> --- drivers/usb/serial/quatech2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)