nfsd4: session needs room for following op to error out

Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 82189b208af3..b9048e5e349e 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1359,6 +1359,12 @@ nfsd4_proc_compound(struct svc_rqst *rqstp,
                 /* If op is non-idempotent */
                 if (opdesc->op_flags & OP_MODIFIES_SOMETHING) {
                         plen = opdesc->op_rsize_bop(rqstp, op);
+                        /*
+                         * If there's still another operation, make sure
+                         * we'll have space to at least encode an error:
+                         */
+                        if (resp->opcnt < args->opcnt)
+                                plen += COMPOUND_ERR_SLACK_SPACE;
                         op->status = nfsd4_check_resp_size(resp, plen);
                 }