1 files changed, 36 insertions, 1 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3e96e02496bd..251dac7579ec 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1439,8 +1439,10 @@ free_session_slots(struct nfsd4_session *ses)
 {
 	int i;
 
-	for (i = 0; i < ses->se_fchannel.maxreqs; i++)
+	for (i = 0; i < ses->se_fchannel.maxreqs; i++) {
+		free_svc_cred(&ses->se_slots[i]->sl_cred);
 		kfree(ses->se_slots[i]);
+	}
 }
 
 /*
@@ -2295,6 +2297,8 @@ nfsd4_store_cache_entry(struct nfsd4_compoundres *resp)
 	slot->sl_flags |= NFSD4_SLOT_INITIALIZED;
 	slot->sl_opcnt = resp->opcnt;
 	slot->sl_status = resp->cstate.status;
+	free_svc_cred(&slot->sl_cred);
+	copy_cred(&slot->sl_cred, &resp->rqstp->rq_cred);
 
 	if (!nfsd4_cache_this(resp)) {
 		slot->sl_flags &= ~NFSD4_SLOT_CACHED;
@@ -3001,6 +3005,34 @@ static bool nfsd4_request_too_big(struct svc_rqst *rqstp,
 	return xb->len > session->se_fchannel.maxreq_sz;
 }
 
+static bool replay_matches_cache(struct svc_rqst *rqstp,
+		 struct nfsd4_sequence *seq, struct nfsd4_slot *slot)
+{
+	struct nfsd4_compoundargs *argp = rqstp->rq_argp;
+
+	if ((bool)(slot->sl_flags & NFSD4_SLOT_CACHETHIS) !=
+	    (bool)seq->cachethis)
+		return false;
+	/*
+	 * If there's an error than the reply can have fewer ops than
+	 * the call.  But if we cached a reply with *more* ops than the
+	 * call you're sending us now, then this new call is clearly not
+	 * really a replay of the old one:
+	 */
+	if (slot->sl_opcnt < argp->opcnt)
+		return false;
+	/* This is the only check explicitly called by spec: */
+	if (!same_creds(&rqstp->rq_cred, &slot->sl_cred))
+		return false;
+	/*
+	 * There may be more comparisons we could actually do, but the
+	 * spec doesn't require us to catch every case where the calls
+	 * don't match (that would require caching the call as well as
+	 * the reply), so we don't bother.
+	 */
+	return true;
+}
+
 __be32
 nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		union nfsd4_op_u *u)
@@ -3060,6 +3092,9 @@ nfsd4_sequence(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 		status = nfserr_seq_misordered;
 		if (!(slot->sl_flags & NFSD4_SLOT_INITIALIZED))
 			goto out_put_session;
+		status = nfserr_seq_false_retry;
+		if (!replay_matches_cache(rqstp, seq, slot))
+			goto out_put_session;
 		cstate->slot = slot;
 		cstate->session = session;
 		cstate->clp = clp;