CVE-2026-89683

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

nfsd: fix dentry ref leak on V4ROOT export filehandle lookup

nfsd set fh dentry() leaks the dentry reference from exportfs decode fh raw() when the NFS3 FHSIZE or NFS FHSIZE switch cases detect NFSEXP V4ROOT and goto out. The out: label calls exp put() but never dput(dentry), and fhp->fh dentry was never assigned so fh put() cannot compensate.

A crafted NFSv3 filehandle targeting a V4ROOT export's fsid triggers the leak on every request.