cifs: enable signing flag in SMB header when server has it on

cifs_sign_smb only generates a signature if the correct Flags2 bit is
set. Make sure that it gets set correctly if we're sending an async
call.

This patch fixes:

    https://bugzilla.kernel.org/show_bug.cgi?id=28142

Reported-and-Tested-by: JG <jg@cms.ac>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index b8c5e2eb43d0..fbc5aace54b1 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -359,6 +359,10 @@ cifs_call_async(struct TCP_Server_Info *server, struct smb_hdr *in_buf,
         if (rc)
                 return rc;
 
+        /* enable signing if server requires it */
+        if (server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
+                in_buf->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
+
         mutex_lock(&server->srv_mutex);
         mid = AllocMidQEntry(in_buf, server);
         if (mid == NULL) {