In the Linux kernel, the following vulnerability has been resolved: usb: gadget: userial: Add null pointer check in gserialresume Consider a case where gserialdisconnect has already cleared gser->ioport. And if a wakeup interrupt triggers afterwards, gserialresume gets called, which will lead to accessing of gser->ioport and thus causing null pointer dereference.Add a null pointer check to prevent this. Added a static spinlock to prevent gser->ioport from becoming null after the newly added check.