From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
If nfsd4_check_resp_size() returns an error then we should really be
truncating the reply here, otherwise we may leave extra garbage at the
end of the rpc reply.
Also add a warning to catch any cases where our reply-size estimates may
be wrong in the case of a non-idempotent operation.
Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
---
fs/nfsd/nfs4xdr.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 6cdd660..fb40dd1 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3633,6 +3633,7 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
{
struct nfs4_stateowner *so = resp->cstate.replay_owner;
__be32 *statp;
+ nfsd4_enc encoder;
__be32 *p;
RESERVE_SPACE(8);
@@ -3644,10 +3645,29 @@ nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
goto status;
BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
!nfsd4_enc_ops[op->opnum]);
- op->status = nfsd4_enc_ops[op->opnum](resp, op->status, &op->u);
+ encoder = nfsd4_enc_ops[op->opnum];
+ op->status = encoder(resp, op->status, &op->u);
/* nfsd4_check_resp_size guarantees enough room for error status */
if (!op->status)
op->status = nfsd4_check_resp_size(resp, 0);
+ if (op->status == nfserr_resource ||
+ op->status == nfserr_rep_too_big ||
+ op->status == nfserr_rep_too_big_to_cache) {
+ /*
+ * The operation may have already been encoded or
+ * partially encoded. No op returns anything additional
+ * in the case of one of these three errors, so we can
+ * just truncate back to after the status. But it's a
+ * bug if we had to do this on a non-idempotent op:
+ */
+ if (OPDESC(op)->op_flags & OP_MODIFIES_SOMETHING) {
+ printk("unable to encode reply to nonidempotent op"
+ " %d (%s)\n", op->opnum,
+ nfsd4_op_name(op->opnum));
+ WARN_ON_ONCE(1);
+ }
+ resp->xdr.p = statp + 1;
+ }
if (so) {
so->so_replay.rp_status = op->status;
so->so_replay.rp_buflen = (char *)resp->xdr.p - (char *)(statp+1);
--
1.7.9.5
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