CVE-2026-45983

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> nfsd: never defer requests during idmap lookup<br /> <br /> During v4 request compound arg decoding, some ops (e.g. SETATTR)<br /> can trigger idmap lookup upcalls. When those upcall responses get<br /> delayed beyond the allowed time limit, cache_check() will mark the<br /> request for deferral and cause it to be dropped.<br /> <br /> This prevents nfs4svc_encode_compoundres from being executed, and<br /> thus the session slot flag NFSD4_SLOT_INUSE never gets cleared.<br /> Subsequent client requests will fail with NFSERR_JUKEBOX, given<br /> that the slot will be marked as in-use, making the SEQUENCE op<br /> fail.<br /> <br /> Fix this by making sure that the RQ_USEDEFERRAL flag is always<br /> clear during nfs4svc_decode_compoundargs(), since no v4 request<br /> should ever be deferred.