Fix a crash in BSON that could happen when converting a Double into an Int of your choosing with the Double being too large

Author: Joannis

Sources/BSON/Codable/Decoding/BSONDecoder.swift

@@ -138,6 +138,13 @@ extension BSONDecoderSettings.IntegerDecodingStrategy {
             case (let int as Int, _):
                 return try int.convert(to: I.self)
             case (let double as Double, .roundingAnyNumber), (let double as Double, .adaptive):
+                guard
+                    double >= Double(I.min),
+                    double <= Double(I.max)
+                else {
+                    throw DecodingError.typeMismatch(Double.self, .init(codingPath: [], debugDescription: "The IntegerDecodingStrategy is adaptive, but the Double could not be converted to \(I.self)"))
+                }
+                
                 return I(double)
             case (let string as String, .adaptive):
                 guard let int = I(string) else {
@@ -177,6 +184,13 @@ extension BSONDecoderSettings.IntegerDecodingStrategy {
         case (.int64, let int as Int), (.adaptive, let int as Int), (.anyInteger, let int as Int), (.roundingAnyNumber, let int as Int):
             return try int.convert(to: I.self)
         case (.roundingAnyNumber, let double as Double), (.adaptive, let double as Double):
+            guard
+                double >= Double(I.min),
+                double <= Double(I.max)
+            else {
+                throw DecodingError.typeMismatch(Double.self, .init(codingPath: [], debugDescription: "The IntegerDecodingStrategy is adaptive, but the Double could not be converted to \(I.self)"))
+            }
+            
             return I(double)
         case (.custom(let strategy), _):
             guard let value: I = try strategy(key, value) else {

Sources/BSON/Codable/Decoding/Fast/FastBSONDecoder.swift

@@ -116,8 +116,18 @@ struct _FastKeyedContainer<Key: CodingKey>: KeyedDecodingContainerProtocol {
             }
 
             return F(int)
+        case .double:
+            guard
+                let double = document.storage.getDouble(at: offset),
+                double >= Double(F.min),
+                double <= Double(F.max)
+            else {
+                throw BSONValueNotFound(type: F.self, path: codingPath.map(\.stringValue) + [key.stringValue])
+            }
+            
+            return F(double)
         default:
-            throw BSONValueNotFound(type: F.self, path: codingPath.map(\.stringValue))
+            throw BSONValueNotFound(type: F.self, path: codingPath.map(\.stringValue) + [key.stringValue])
         }
     }
 
@@ -127,7 +137,7 @@ struct _FastKeyedContainer<Key: CodingKey>: KeyedDecodingContainerProtocol {
             type == .boolean,
             let int: UInt8 = document.storage.getInteger(at: offset, endianness: .little)
         else {
-            throw BSONValueNotFound(type: Bool.self, path: codingPath.map(\.stringValue))
+            throw BSONValueNotFound(type: Bool.self, path: codingPath.map(\.stringValue) + [key.stringValue])
         }
 
         return int == 0x01
@@ -139,7 +149,7 @@ struct _FastKeyedContainer<Key: CodingKey>: KeyedDecodingContainerProtocol {
             type == .string,
             let string = document.storage.getBSONString(at: offset)
         else {
-            throw BSONValueNotFound(type: String.self, path: codingPath.map(\.stringValue))
+            throw BSONValueNotFound(type: String.self, path: codingPath.map(\.stringValue) + [key.stringValue])
         }
 
         return string
@@ -151,7 +161,7 @@ struct _FastKeyedContainer<Key: CodingKey>: KeyedDecodingContainerProtocol {
             type == .double,
             let double = document.storage.getDouble(at: offset)
         else {
-            throw BSONValueNotFound(type: Double.self, path: codingPath.map(\.stringValue))
+            throw BSONValueNotFound(type: String.self, path: codingPath.map(\.stringValue) + [key.stringValue])
         }
 
         return double
@@ -690,6 +700,16 @@ struct _FastUnkeyedContainer: UnkeyedDecodingContainer {
 
             currentIndex += 1
             return F(int)
+        case .double:
+            guard
+                let double = document.storage.getDouble(at: offset),
+                double >= Double(F.min),
+                double <= Double(F.max)
+            else {
+                throw BSONValueNotFound(type: F.self, path: codingPath.map(\.stringValue))
+            }
+            
+            return F(double)
         default:
             throw BSONValueNotFound(type: F.self, path: codingPath.map(\.stringValue))
         }