!1755 [sync] PR-1737: ksmbd: fix out of bounds read in smb2_sess_setup

Merge Pull Request from: @openeuler-sync-bot 
 

Origin pull request: 
https://gitee.com/openeuler/kernel/pulls/1737 
 
PR sync from: Li Nan <linan122@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/BK3WNMWIWF7LUE5WR6V4SB366MLOBVAY/ 
 
https://gitee.com/openeuler/kernel/issues/I7SVRC 
 
Link:https://gitee.com/openeuler/kernel/pulls/1755 

Reviewed-by: Jialin Zhang <zhangjialin11@huawei.com> 
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> 

fs/ksmbd/smb2pdu.c

@@ -1304,9 +1304,8 @@ static int decode_negotiation_token(struct ksmbd_conn *conn,
 
 static int ntlm_negotiate(struct ksmbd_work *work,
 			  struct negotiate_message *negblob,
-			  size_t negblob_len)
+			  size_t negblob_len, struct smb2_sess_setup_rsp *rsp)
 {
-	struct smb2_sess_setup_rsp *rsp = smb2_get_msg(work->response_buf);
 	struct challenge_message *chgblob;
 	unsigned char *spnego_blob = NULL;
 	u16 spnego_blob_len;
@@ -1411,10 +1410,10 @@ static struct ksmbd_user *session_user(struct ksmbd_conn *conn,
 	return user;
 }
 
-static int ntlm_authenticate(struct ksmbd_work *work)
+static int ntlm_authenticate(struct ksmbd_work *work,
+			     struct smb2_sess_setup_req *req,
+			     struct smb2_sess_setup_rsp *rsp)
 {
-	struct smb2_sess_setup_req *req = smb2_get_msg(work->request_buf);
-	struct smb2_sess_setup_rsp *rsp = smb2_get_msg(work->response_buf);
 	struct ksmbd_conn *conn = work->conn;
 	struct ksmbd_session *sess = work->sess;
 	struct channel *chann = NULL;
@@ -1552,10 +1551,10 @@ static int ntlm_authenticate(struct ksmbd_work *work)
 }
 
 #ifdef CONFIG_SMB_SERVER_KERBEROS5
-static int krb5_authenticate(struct ksmbd_work *work)
+static int krb5_authenticate(struct ksmbd_work *work,
+			     struct smb2_sess_setup_req *req,
+			     struct smb2_sess_setup_rsp *rsp)
 {
-	struct smb2_sess_setup_req *req = smb2_get_msg(work->request_buf);
-	struct smb2_sess_setup_rsp *rsp = smb2_get_msg(work->response_buf);
 	struct ksmbd_conn *conn = work->conn;
 	struct ksmbd_session *sess = work->sess;
 	char *in_blob, *out_blob;
@@ -1637,7 +1636,9 @@ static int krb5_authenticate(struct ksmbd_work *work)
 	return 0;
 }
 #else
-static int krb5_authenticate(struct ksmbd_work *work)
+static int krb5_authenticate(struct ksmbd_work *work,
+			     struct smb2_sess_setup_req *req,
+			     struct smb2_sess_setup_rsp *rsp)
 {
 	return -EOPNOTSUPP;
 }
@@ -1646,8 +1647,8 @@ static int krb5_authenticate(struct ksmbd_work *work)
 int smb2_sess_setup(struct ksmbd_work *work)
 {
 	struct ksmbd_conn *conn = work->conn;
-	struct smb2_sess_setup_req *req = smb2_get_msg(work->request_buf);
-	struct smb2_sess_setup_rsp *rsp = smb2_get_msg(work->response_buf);
+	struct smb2_sess_setup_req *req;
+	struct smb2_sess_setup_rsp *rsp;
 	struct ksmbd_session *sess;
 	struct negotiate_message *negblob;
 	unsigned int negblob_len, negblob_off;
@@ -1655,6 +1656,8 @@ int smb2_sess_setup(struct ksmbd_work *work)
 
 	ksmbd_debug(SMB, "Received request for session setup\n");
 
+	WORK_BUFFERS(work, req, rsp);
+
 	rsp->StructureSize = cpu_to_le16(9);
 	rsp->SessionFlags = 0;
 	rsp->SecurityBufferOffset = cpu_to_le16(72);
@@ -1756,7 +1759,7 @@ int smb2_sess_setup(struct ksmbd_work *work)
 
 		if (conn->preferred_auth_mech &
 				(KSMBD_AUTH_KRB5 | KSMBD_AUTH_MSKRB5)) {
-			rc = krb5_authenticate(work);
+			rc = krb5_authenticate(work, req, rsp);
 			if (rc) {
 				rc = -EINVAL;
 				goto out_err;
@@ -1768,7 +1771,7 @@ int smb2_sess_setup(struct ksmbd_work *work)
 			sess->Preauth_HashValue = NULL;
 		} else if (conn->preferred_auth_mech == KSMBD_AUTH_NTLMSSP) {
 			if (negblob->MessageType == NtLmNegotiate) {
-				rc = ntlm_negotiate(work, negblob, negblob_len);
+				rc = ntlm_negotiate(work, negblob, negblob_len, rsp);
 				if (rc)
 					goto out_err;
 				rsp->hdr.Status =
@@ -1781,7 +1784,7 @@ int smb2_sess_setup(struct ksmbd_work *work)
 						le16_to_cpu(rsp->SecurityBufferLength) - 1);
 
 			} else if (negblob->MessageType == NtLmAuthenticate) {
-				rc = ntlm_authenticate(work);
+				rc = ntlm_authenticate(work, req, rsp);
 				if (rc)
 					goto out_err;