CVE-2025-40214 af_unix: Initialise scc_index in unix_add_edge().

In the Linux kernel, the following vulnerability has been resolved: afunix: Initialise sccindex in unixaddedge. Quang Le reported that the AFUNIX GC could garbage-collect a receive queue of an alive in-flight socket, with a nice repro. The repro consists of three stages. 1 1-a. Create a single...