In the Linux kernel, the following vulnerability has been resolved:pinmux: Use sequential access to access desc->pinmux dataWhen two client of the same gpio call pinctrl_select_state() for the
same functionality, we are seeing NULL pointer issue while accessing
desc->mux_owner.Let's say two processes A, B executing in pin_request() for the same pin
and process A updates the desc->mux_usecount but not yet updated the
desc->mux_owner while process B see the desc->mux_usecount which got
updated by A path and further executes strcmp and while accessing
desc->mux_owner it crashes with NULL pointer.Serialize the access to mux related setting with a mutex lock.pinctrl_select_state() {		  pinctrl_select_state() {
  pin_request() {				pin_request() {
  ...
						 ....
    } else {
         desc->mux_usecount++;
    						desc->mux_usecount && strcmp(desc->mux_owner, owner)) {}						}