From: Trond Myklebust <trond.myklebust@primarydata.com>
Date: Fri, 12 Jan 2018 22:42:30 +0000 (-0500)
Subject: nfsd: Detect unhashed stids in nfsd4_verify_open_stid()
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=4f1764172a0aa7395d12b96cae640ca1438c5085;p=openwrt%2Fstaging%2Fblogic.git

nfsd: Detect unhashed stids in nfsd4_verify_open_stid()

The state of the stid is guaranteed by 2 locks:
- The nfs4_client 'cl_lock' spinlock
- The nfs4_ol_stateid 'st_mutex' mutex

so it is quite possible for the stid to be unhashed after lookup,
but before calling nfsd4_lock_ol_stateid(). So we do need to check
for a zero value for 'sc_type' in nfsd4_verify_open_stid().

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Tested-by: Checuk Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 659aefb68eca "nfsd: Ensure we don't recognise lock stateids..."
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index b29b5a185a2c..5a75135f5f53 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3590,6 +3590,7 @@ nfsd4_verify_open_stid(struct nfs4_stid *s)
 	switch (s->sc_type) {
 	default:
 		break;
+	case 0:
 	case NFS4_CLOSED_STID:
 	case NFS4_CLOSED_DELEG_STID:
 		ret = nfserr_bad_stateid;