nfsd4: ignore WANT bits in open downgrade

commit c30e92df30d7d5fe65262fbce5d1b7de675fe34e upstream.

We don't use WANT bits yet--and sending them can probably trigger a
BUG() further down.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 3d893645cc6..ecd8152965e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3421,6 +3421,8 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp,
         if (!access_valid(od->od_share_access, cstate->minorversion)
                         || !deny_valid(od->od_share_deny))
                 return nfserr_inval;
+        /* We don't yet support WANT bits: */
+        od->od_share_access &= NFS4_SHARE_ACCESS_MASK;
 
         nfs4_lock_state();
         if ((status = nfs4_preprocess_seqid_op(cstate,