nfsd41: add flag checking for create_session

Teach the NFS server to reject invalid create_session flags.

Also do some minor formatting adjustments.

Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

2 files changed, 8 insertions, 3 deletions

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index fbde6f79922e..6dbaa379c863 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -1515,6 +1515,9 @@ nfsd4_create_session(struct svc_rqst *rqstp,
         bool confirm_me = false;
         int status = 0;
 
+        if (cr_ses->flags & ~SESSION4_FLAG_MASK_A)
+                return nfserr_inval;
+
         nfs4_lock_state();
         unconf = find_unconfirmed_client(&cr_ses->clientid);
         conf = find_confirmed_client(&cr_ses->clientid);
diff --git a/include/linux/nfs4.h b/include/linux/nfs4.h
index b528f6d4b860..8937727e7039 100644
--- a/include/linux/nfs4.h
+++ b/include/linux/nfs4.h
@@ -570,9 +570,11 @@ struct nfs4_sessionid {
 };
 
 /* Create Session Flags */
-#define SESSION4_PERSIST         0x001
-#define SESSION4_BACK_CHAN       0x002
-#define SESSION4_RDMA            0x004
+#define SESSION4_PERSIST        0x001
+#define SESSION4_BACK_CHAN      0x002
+#define SESSION4_RDMA           0x004
+
+#define SESSION4_FLAG_MASK_A    0x007
 
 enum state_protect_how4 {
         SP4_NONE        = 0,