Check for overflow when parsing datetime

chronotope · May 26, 2022 · dfc4027 · dfc4027
1 parent bbc50f8
commit dfc4027
Show file tree

Hide file tree

Showing 2 changed files with 7 additions and 0 deletions.
diff --git a/src/datetime/tests.rs b/src/datetime/tests.rs
@@ -130,6 +130,7 @@ fn test_datetime_rfc2822_and_rfc3339() {
         DateTime::parse_from_rfc3339("2015-02-18T23:59:60.234567+05:00"),
         Ok(edt.ymd(2015, 2, 18).and_hms_micro(23, 59, 59, 1_234_567))
     );
+    assert!(DateTime::parse_from_rfc2822("31 DEC 262143 23:59 -2359").is_err());
 }
 
 #[test]

diff --git a/src/format/parsed.rs b/src/format/parsed.rs
@@ -626,6 +626,12 @@ impl Parsed {
         let offset = self.offset.ok_or(NOT_ENOUGH)?;
         let datetime = self.to_naive_datetime_with_offset(offset)?;
         let offset = FixedOffset::east_opt(offset).ok_or(OUT_OF_RANGE)?;
+
+        // this is used to prevent an overflow when calling FixedOffset::from_local_datetime
+        datetime
+            .checked_sub_signed(OldDuration::seconds(i64::from(offset.local_minus_utc())))
+            .ok_or(OUT_OF_RANGE)?;
+
         match offset.from_local_datetime(&datetime) {
             LocalResult::None => Err(IMPOSSIBLE),
             LocalResult::Single(t) => Ok(t),