In the Linux kernel, the following vulnerability has been resolved:
usb: mtu3: fix kernel panic at qmu transfer done irq handler
When handle qmu transfer irq, it will unlock @mtu->lock before give back request, if another thread handle disconnect event at the same time, and try to disable ep, it may lock @mtu->lock and free qmu ring, then qmu irq hanlder may get a NULL gpd, avoid the KE by checking gpds value before handling it.
e.g. qmu done irq on cpu0 thread running on cpu1
qmu_done_tx() handle gpd [0] mtu3_requ_complete() mtu3_gadget_ep_disable() unlock @mtu->lock give back request lock @mtu->lock mtu3_ep_disable() mtu3_gpd_ring_free() unlock @mtu->lock lock @mtu->lock get next gpd [1]
[1]: goto [0] to handle next gpd, and next gpd may be NULL.