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.
https://git.kernel.org/stable/c/d493cf57f4c4dae5396cd6ad41e5c209d0615a81
https://git.kernel.org/stable/c/c1ae0f973bcba5730871e35976a0ab6878fdac34
https://git.kernel.org/stable/c/6247023fbbec1325029f2d5f2a7cdc0f9f9ea15a
https://git.kernel.org/stable/c/11db8df188b34bdb8c6a3a0bf438e5fc8cd75aca