CVE-2026-31532 can: raw: fix ro->uniq use-after-free in raw_rcv()

In the Linux kernel, the following vulnerability has been resolved: can: raw: fix ro-uniq use-after-free in rawrcv rawrelease unregisters raw CAN receive filters via canrxunregister, but receiver deletion is deferred with callrcu. This leaves a window where rawrcv may still be running in an RCU...