CVE-2026-63804 gfs2: fix use-after-free in gfs2_qd_dealloc

In the Linux kernel, the following vulnerability has been resolved: gfs2: fix use-after-free in gfs2qddealloc gfs2qddealloc, called as an RCU callback from gfs2qddispose, accesses the superblock object sdp through qd-qdsbd after freeing qd. It does so to decrement sdquotacount and wake up...