Reproduction steps:
1. Open the attached project “IN-29656“
2. In the Hierarchy select any child Terrain of the “Map“ GameObject
3. In the Inspector for the Terrain component select the “Paint Details” tab
4. Paint grass on the Terrain GameObject in Scene window

Expected result: The Editor does not crash
Actual result: The Editor crashes

Reproducible with: 2022.2.0a13, 2022.2.6f1, 2023.1.0b4, 2023.2.0a2
Not reproducible with: 2020.3.45f1, 2021.3.18f1, 2022.2.0a12

Reproduced on: Windows 10 Pro

Note: If the Editor does not crash immediately, repeat step 4 until it does

First few lines of the stack trace:
{{0x00007ff701ff5712 (Unity) TerrainData_CUSTOM_Internal_SetDetailLayer }}
{{0x0000023209962fe4 (Mono JIT Code) (wrapper managed-to-native) UnityEngine.TerrainData:Internal_SetDetailLayer (UnityEngine.TerrainData,int,int,int,int,int,int[,]) }}
{{0x0000023209962edb (Mono JIT Code) UnityEngine.TerrainData:SetDetailLayer (int,int,int,int[,]) }}
{{0x0000023209962e1b (Mono JIT Code) UnityEngine.TerrainData:SetDetailLayer (UnityEngine.Vector2Int,int,int[,]) }}
{{0x000002320838aa5b (Mono JIT Code) UnityEditor.TerrainTools.PaintDetailsTool:OnPaint (UnityEngine.Terrain,UnityEditor.TerrainTools.IOnPaint) 52}}