CVE-2026-89694

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

nfsd: check client ownership when cancelling a copy-notify stateid

On the OFFLOAD CANCEL path (clp != NULL), manage cpntf state() freed the target cpntf state without checking ownership. The lookup key st->si opaque.so id is allocated cyclically (guessable) and the embedded clientid is the fixed per-net nn->s2s cp cl id, so any authenticated NFSv4.2 client could cancel and free another client's copy-notify stateid.

Compare the creating clientid recorded in state->cp p clid against the requesting client's cl clientid and return nfserr bad stateid on a mismatch instead of freeing the entry.