CVE-2026-89673

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

nfsd: fix XDR padding calculation in ff encode getdeviceinfo

nfsd4 ff encode getdeviceinfo() computes the da addr body reservation as 16 + netid len + addr len, but the subsequent xdr encode opaque() calls emit 8 + round up(netid len, 4) + round up(addr len, 4) bytes. The mismatch means the declared da addr body length exceeds the actual encoded data by 2-8 bytes on every flexfile GETDEVICEINFO reply, leaking stale reply-page content to the client and mis-aligning the subsequent version list decode.

Use xdr align size() for each string length to match what xdr encode opaque() actually writes.