CVE-2024-26689 ceph: prevent use-after-free in encode_cap_msg()

In the Linux kernel, the following vulnerability has been resolved: ceph: prevent use-after-free in encodecapmsg In fs/ceph/caps.c, in encodecapmsg, "use after free" error was caught by KASAN at this line - 'cephbuffergetarg-xattrbuf;'. This implies before the refcount could be increment here, it...