[CIFS] use krb5 session key from first SMB session after a NegProt

Currently, any new kerberos SMB session overwrites the server's session
key. The session key should only be set by the first SMB session set up
on the socket.

Signed-off-by: Jeff Layton <jlayton@tupile.poochiereds.net>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index d0cb469daab7..ce698d5f6107 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -528,9 +528,11 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
                         rc = -EOVERFLOW;
                         goto ssetup_exit;
                 }
-                ses->server->mac_signing_key.len = msg->sesskey_len;
-                memcpy(ses->server->mac_signing_key.data.krb5, msg->data,
-                        msg->sesskey_len);
+                if (first_time) {
+                        ses->server->mac_signing_key.len = msg->sesskey_len;
+                        memcpy(ses->server->mac_signing_key.data.krb5,
+                                msg->data, msg->sesskey_len);
+                }
                 pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
                 capabilities |= CAP_EXTENDED_SECURITY;
                 pSMB->req.Capabilities = cpu_to_le32(capabilities);