ksmbd: Fix an error handling path in 'smb2_sess_setup()'

All the error handling paths of 'smb2_sess_setup()' end to 'out_err'.

All but the new error handling path added by the commit given in the Fixes
tag below.

Fix this error handling path and branch to 'out_err' as well.

Fixes: 0d994cd ("ksmbd: add buffer validation in session setup")
Cc: stable@vger.kernel.org # v5.15
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: tititiou36

fs/ksmbd/smb2pdu.c

@@ -1697,8 +1697,10 @@ int smb2_sess_setup(struct ksmbd_work *work)
 	negblob_off = le16_to_cpu(req->SecurityBufferOffset);
 	negblob_len = le16_to_cpu(req->SecurityBufferLength);
 	if (negblob_off < offsetof(struct smb2_sess_setup_req, Buffer) ||
-	    negblob_len < offsetof(struct negotiate_message, NegotiateFlags))
-		return -EINVAL;
+	    negblob_len < offsetof(struct negotiate_message, NegotiateFlags)) {
+		rc = -EINVAL;
+		goto out_err;
+	}
 
 	negblob = (struct negotiate_message *)((char *)&req->hdr.ProtocolId +
 			negblob_off);