CVE-2026-89683

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < d493cf57f4c4dae5396cd6ad41e5c209d0615a81affected
LinuxLinuxef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < c1ae0f973bcba5730871e35976a0ab6878fdac34affected
LinuxLinuxef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < 11db8df188b34bdb8c6a3a0bf438e5fc8cd75acaaffected
LinuxLinuxef7f6c4904d03ccd7478e1ac20ed75f79c4ac444 < 6247023fbbec1325029f2d5f2a7cdc0f9f9ea15aaffected
LinuxLinux6.12affected
LinuxLinux0 < 6.12unaffected
LinuxLinux6.12.109 <= 6.12.*unaffected
LinuxLinux6.18.50 <= 6.18.*unaffected
LinuxLinux7.2.4 <= 7.2.*unaffected
LinuxLinux7.3-rc1 <= *unaffected

Weaknesses

References