ksmbd: add bounds check for durable handle context

Add missing bounds check for durable handle context.

Cc: stable@vger.kernel.org
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: namjaejeon

fs/smb/server/smb2pdu.c

@@ -2708,6 +2708,13 @@ static int parse_durable_handle_context(struct ksmbd_work *work,
 				goto out;
 			}
 
+			if (le16_to_cpu(context->DataOffset) +
+				le32_to_cpu(context->DataLength) <
+			    sizeof(struct create_durable_reconn_v2_req)) {
+				err = -EINVAL;
+				goto out;
+			}
+
 			recon_v2 = (struct create_durable_reconn_v2_req *)context;
 			persistent_id = recon_v2->Fid.PersistentFileId;
 			dh_info->fp = ksmbd_lookup_durable_fd(persistent_id);
@@ -2741,6 +2748,13 @@ static int parse_durable_handle_context(struct ksmbd_work *work,
 				goto out;
 			}
 
+			if (le16_to_cpu(context->DataOffset) +
+				le32_to_cpu(context->DataLength) <
+			    sizeof(struct create_durable_reconn_req)) {
+				err = -EINVAL;
+				goto out;
+			}
+
 			recon = (struct create_durable_reconn_req *)context;
 			persistent_id = recon->Data.Fid.PersistentFileId;
 			dh_info->fp = ksmbd_lookup_durable_fd(persistent_id);
@@ -2766,6 +2780,13 @@ static int parse_durable_handle_context(struct ksmbd_work *work,
 				goto out;
 			}
 
+			if (le16_to_cpu(context->DataOffset) +
+				le32_to_cpu(context->DataLength) <
+			    sizeof(struct create_durable_req_v2)) {
+				err = -EINVAL;
+				goto out;
+			}
+
 			durable_v2_blob =
 				(struct create_durable_req_v2 *)context;
 			ksmbd_debug(SMB, "Request for durable v2 open\n");