CVE-2026-52957 libceph: Fix potential null-ptr-deref in decode_choose_args()

In the Linux kernel, the following vulnerability has been resolved: libceph: Fix potential null-ptr-deref in decodechooseargs A message of type CEPHMSGOSDMAP contains an OSD map that itself contains a CRUSH map. When decoding this CRUSH map in crushdecode, an array of maxbuckets CRUSH buckets is...