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.

Fixes: efcae97fa425 ("NFSD: da_addr_body field missing in some GETDEVICEINFO replies")
Cc: stable@vger.kernel.org
Assisted-by: kres:claude-opus-4-6
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260527-pnfs-fixes-v1-1-784f39dc1eca@kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

0 files changed, 0 insertions, 0 deletions