diff options
| -rw-r--r-- | src/backend/utils/sort/tuplesort.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/src/backend/utils/sort/tuplesort.c b/src/backend/utils/sort/tuplesort.c index 18cb046f198..9b61a893ca1 100644 --- a/src/backend/utils/sort/tuplesort.c +++ b/src/backend/utils/sort/tuplesort.c @@ -2729,7 +2729,7 @@ tuplesort_heap_siftup(Tuplesortstate *state, bool checkIndex) { SortTuple *memtuples = state->memtuples; SortTuple *tuple; - int i, + unsigned int i, n; if (--state->memtupcount <= 0) @@ -2737,12 +2737,17 @@ tuplesort_heap_siftup(Tuplesortstate *state, bool checkIndex) CHECK_FOR_INTERRUPTS(); + /* + * state->memtupcount is "int", but we use "unsigned int" for i, j, n. + * This prevents overflow in the "2 * i + 1" calculation, since at the top + * of the loop we must have i < n <= INT_MAX <= UINT_MAX/2. + */ n = state->memtupcount; tuple = &memtuples[n]; /* tuple that must be reinserted */ i = 0; /* i is where the "hole" is */ for (;;) { - int j = 2 * i + 1; + unsigned int j = 2 * i + 1; if (j >= n) break; |