CVE-2026-72379 fs: refuse O_TMPFILE creation with an unmapped fsuid or fsgid

In the Linux kernel, the following vulnerability has been resolved: fs: refuse OTMPFILE creation with an unmapped fsuid or fsgid vfstmpfile never checked that the caller's fsuid and fsgid map into the filesystem. On an idmapped mount whose idmapping does not cover the caller's fsu,gid, the -tmpfi...