usb: gadget: u_serial: Add null pointer check in gserial_suspend

Consider a case where gserial_disconnect has already cleared
gser->ioport. And if gserial_suspend gets called afterwards,
it will lead to accessing of gser->ioport and thus causing
null pointer dereference.

Avoid this by adding a null pointer check. Added a static
spinlock to prevent gser->ioport from becoming null after
the newly added null pointer check.

Fixes: aba3a8d01d ("usb: gadget: u_serial: add suspend resume callbacks")
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Link: https://lore.kernel.org/r/1683278317-11774-1-git-send-email-quic_prashk@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Prashanth K 2023-05-05 14:48:37 +05:30 committed by Greg Kroah-Hartman
parent 24520e51ff
commit 2f6ecb89fe
1 changed files with 11 additions and 2 deletions

View File

@ -1420,10 +1420,19 @@ EXPORT_SYMBOL_GPL(gserial_disconnect);
void gserial_suspend(struct gserial *gser) void gserial_suspend(struct gserial *gser)
{ {
struct gs_port *port = gser->ioport; struct gs_port *port;
unsigned long flags; unsigned long flags;
spin_lock_irqsave(&port->port_lock, flags); spin_lock_irqsave(&serial_port_lock, flags);
port = gser->ioport;
if (!port) {
spin_unlock_irqrestore(&serial_port_lock, flags);
return;
}
spin_lock(&port->port_lock);
spin_unlock(&serial_port_lock);
port->suspended = true; port->suspended = true;
spin_unlock_irqrestore(&port->port_lock, flags); spin_unlock_irqrestore(&port->port_lock, flags);
} }