From: J. Bruce Fields <bfields@redhat.com>
Date: Mon, 13 Feb 2012 21:56:19 +0000 (-0500)
Subject: nfsd4: check for uninitialized slot
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=bf5c43c8f155e755b0fc3dfa76f9f8c6e2c0161f;p=linux.git

nfsd4: check for uninitialized slot

This fixes an oops when a buggy client tries to use an initial seqid of
0 on a new slot, which we may misinterpret as a replay.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index e0e706f8918d2..2387791ea0503 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1347,6 +1347,7 @@ nfsd4_store_cache_entry(struct nfsd4_compoundres *resp)
 	slot->sl_opcnt = resp->opcnt;
 	slot->sl_status = resp->cstate.status;
 
+	slot->sl_flags |= NFSD4_SLOT_INITIALIZED;
 	if (nfsd4_not_cached(resp)) {
 		slot->sl_datalen = 0;
 		return;
@@ -1916,6 +1917,9 @@ nfsd4_sequence(struct svc_rqst *rqstp,
 	status = check_slot_seqid(seq->seqid, slot->sl_seqid,
 					slot->sl_flags & NFSD4_SLOT_INUSE);
 	if (status == nfserr_replay_cache) {
+		status = nfserr_seq_misordered;
+		if (!(slot->sl_flags & NFSD4_SLOT_INITIALIZED))
+			goto out;
 		cstate->slot = slot;
 		cstate->session = session;
 		/* Return the cached reply status and set cstate->status
@@ -1932,9 +1936,11 @@ nfsd4_sequence(struct svc_rqst *rqstp,
 
 	/* Success! bump slot seqid */
 	slot->sl_seqid = seq->seqid;
-	slot->sl_flags = NFSD4_SLOT_INUSE;
+	slot->sl_flags |= NFSD4_SLOT_INUSE;
 	if (seq->cachethis)
 		slot->sl_flags |= NFSD4_SLOT_CACHETHIS;
+	else
+		slot->sl_flags &= ~NFSD4_SLOT_CACHETHIS;
 
 	cstate->slot = slot;
 	cstate->session = session;
diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h
index 122217fe9155b..d8f52a0f49880 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -134,6 +134,7 @@ struct nfsd4_slot {
 	u16	sl_opcnt;
 #define NFSD4_SLOT_INUSE	(1 << 0)
 #define NFSD4_SLOT_CACHETHIS	(1 << 1)
+#define NFSD4_SLOT_INITIALIZED	(1 << 2)
 	u8	sl_flags;
 	char	sl_data[];
 };