| タイトル | tdunning t-digest 3.3 Unvalidated NaN Centroid Means Cause Quadratic Blowup |
|---|
| 説明 | While digging further into MergingDigest.fromBytes() past the array-bounds issue I already reported, I noticed it also skips the one check every other write path in this class enforces: rejecting NaN means. MergingDigest.add(double, int) throws on NaN, and even the sibling AVLTreeDigest.fromBytes() routes through add() so it inherits that check for free — but MergingDigest.fromBytes() writes straight into the backing arrays and never calls add(), so a digest can be deserialized with an arbitrary number of NaN means baked in. The very next merge of that digest — a single add(x, w) call, exactly what a real aggregator does with each new raw value — hands those NaNs to Sort.quickSort(), whose median-of-three pivot logic silently degrades from O(n log n) to O(n²) once comparisons stop forming a total order. |
|---|
| ソース | ⚠️ https://github.com/tdunning/t-digest/issues/229 |
|---|
| ユーザー | Yu_Bao from PayPal Cyber Security Team (UID 100783) |
|---|
| 送信 | 2026年08月24日 18:41 (2 月 ago) |
|---|
| モデレーション | 2026年09月19日 19:04 (26 days later) |
|---|
| ステータス | 重複 |
|---|
| VulDBエントリ | 401776 [tdunning t-digest 迄 3.3 MergingDigest.fromBytes 特権昇格] |
|---|
| ポイント | 0 |
|---|