Fix panic with invalid system time (#469)

src/error.rs

@@ -132,6 +132,13 @@ pub enum DecodeError {
         nanos: u32,
     },
 
+    /// The decoder tried to decode a SystemTime and overflowed
+    InvalidSystemTime {
+        /// The duration which could not have been added to
+        /// [`UNIX_EPOCH`](std::time::SystemTime::UNIX_EPOCH)
+        duration: core::time::Duration,
+    },
+
     /// The decoder tried to decode a `CStr` or `CString`, but the incoming data contained a 0 byte
     #[cfg(feature = "std")]
     CStrNulError {

src/features/impl_std.rs

@@ -199,7 +199,10 @@ impl Encode for SystemTime {
 impl Decode for SystemTime {
     fn decode<D: Decoder>(decoder: D) -> Result<Self, DecodeError> {
         let duration = Duration::decode(decoder)?;
-        Ok(SystemTime::UNIX_EPOCH + duration)
+        match SystemTime::UNIX_EPOCH.checked_add(duration) {
+            Some(t) => Ok(t),
+            None => Err(DecodeError::InvalidSystemTime { duration }),
+        }
     }
 }
 

tests/std.rs

@@ -119,3 +119,18 @@ fn test_std_commons() {
     assert_eq!(path, decoded);
     assert_eq!(len, 21);
 }
+
+#[test]
+fn test_system_time_out_of_range() {
+    let mut input = [0xfd, 0x90, 0x0c, 0xfd, 0xfd, 0x90, 0x0c, 0xfd, 0x90, 0x90];
+
+    let result: Result<(std::time::SystemTime, usize), _> =
+        bincode::decode_from_slice(&mut input, Configuration::standard());
+
+    assert_eq!(
+        result.unwrap_err(),
+        bincode::error::DecodeError::InvalidSystemTime {
+            duration: std::time::Duration::new(10447520527445462160, 144),
+        }
+    );
+}