(arrow-rs) branch 56_maintenance updated: [56_maintenance] Prevent Rows row index overflow (#9817) (#9913)

[alamb]

This is an automated email from the ASF dual-hosted git repository.

alamb pushed a commit to branch 56_maintenance
in repository https://gitbox.apache.org/repos/asf/arrow-rs.git


The following commit(s) were added to refs/heads/56_maintenance by this push:
     new 3855ee5923 [56_maintenance] Prevent Rows row index overflow (#9817) 
(#9913)
3855ee5923 is described below

commit 3855ee5923325b9f7f26d856860ab32e0023a2ff
Author: Andrew Lamb <and...@nerdnetworks.org>
AuthorDate: Wed May 6 09:56:59 2026 -0400

    [56_maintenance] Prevent Rows row index overflow (#9817) (#9913)
    
    - Part of https://github.com/apache/arrow-rs/issues/9857
    - Fixes https://github.com/apache/arrow-rs/issues/9901 in 56.x releases
    
    This PR:
    - Backports https://github.com/apache/arrow-rs/pull/9817 from @alamb to
    the `56_maintenance` line
---
 arrow-row/src/lib.rs | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/arrow-row/src/lib.rs b/arrow-row/src/lib.rs
index cdb52a8ee7..7e6cbc3bcc 100644
--- a/arrow-row/src/lib.rs
+++ b/arrow-row/src/lib.rs
@@ -1020,14 +1020,20 @@ impl Rows {
 
     /// Returns the row at index `row`
     pub fn row(&self, row: usize) -> Row<'_> {
-        assert!(row + 1 < self.offsets.len());
+        self.checked_row_end(row);
         unsafe { self.row_unchecked(row) }
     }
 
+    fn checked_row_end(&self, row: usize) -> usize {
+        row.checked_add(1)
+            .filter(|end| *end < self.offsets.len())
+            .expect("row index out of bounds")
+    }
+
     /// Returns the row at `index` without bounds checking
     ///
     /// # Safety
-    /// Caller must ensure that `index` is less than the number of offsets 
(#rows + 1)
+    /// Caller must ensure that `index + 1` is less than the number of offsets 
(#rows + 1)
     pub unsafe fn row_unchecked(&self, index: usize) -> Row<'_> {
         let end = unsafe { self.offsets.get_unchecked(index + 1) };
         let start = unsafe { self.offsets.get_unchecked(index) };
@@ -3588,4 +3594,13 @@ mod tests {
         assert_eq!(unchecked_values_len, 13);
         assert!(checked_values_len > unchecked_values_len);
     }
+
+    #[test]
+    #[should_panic(expected = "row index out of bounds")]
+    fn row_should_panic_on_overflowing_index() {
+        let rows = RowConverter::new(vec![SortField::new(DataType::Int32)])
+            .unwrap()
+            .empty_rows(0, 0);
+        rows.row(usize::MAX);
+    }
 }