[CASSANDRA-12568] Null Dereference

• Type: Sub-task
• Status: Resolved
• Priority: Normal
• Resolution: Not A Problem
• Assignee: Unassigned
• Reporter: Eduardo Aguinaga
• Created: 30/Aug/16 12:17
• Updated: 16/Apr/19 09:30
• Resolved: 31/Aug/16 00:55

Description

Overview:
In May through June of 2016 a static analysis was performed on version 3.0.5 of the Cassandra source code. The analysis included an automated analysis using HP Fortify v4.21 SCA and a manual analysis utilizing SciTools Understand v4. The results of that analysis includes the issue below.

Issue:
In the file ReplicationAwareTokenAllocator.java on line 189 the object curr may be null causing a null dereference.

The member first is initialized to null on line 175. If the for loop that begins on line 176 is never entered, curr will be assigned the value of first (which would be null in this example) on line 185. This will result in a null dereference on line 189.

ReplicationAwareTokenAllocator.java, lines 171-193:
171 private TokenInfo<Unit> createTokenInfos(Map<Unit, UnitInfo<Unit>> units, GroupInfo newUnitGroup)
172 {
173     // build the circular list
174     TokenInfo<Unit> prev = null;
175     TokenInfo<Unit> first = null;
176     for (Map.Entry<Token, Unit> en : sortedTokens.entrySet())
177     {
178         Token t = en.getKey();
179         UnitInfo<Unit> ni = units.get(en.getValue());
180         TokenInfo<Unit> ti = new TokenInfo<>(t, ni);
181         first = ti.insertAfter(first, prev);
182         prev = ti;
183     }
184 
185     TokenInfo<Unit> curr = first;
186     do
187     {
188         populateTokenInfoAndAdjustUnit(curr, newUnitGroup);
189         curr = curr.next;
190     } while (curr != first);
191 
192     return first;
193 }