CVE-2023-52448

In the Linux kernel, the following vulnerability has been resolved:

gfs2: Fix kernel NULL pointer dereference in gfs2_rgrp_dump

Syzkaller has reported a NULL pointer dereference when accessing
rgd->rd_rgl in gfs2_rgrp_dump().  This can happen when creating
rgd->rd_gl fails in read_rindex_entry().  Add a NULL pointer check in
gfs2_rgrp_dump() to prevent that.