Hi all,
I find a potential memory leak in PostgresSQL 14.1, which is in the function setup_config (./src/bin/initdb/initdb.c).
Specifically, at line 1095, function pretty_wal_size() is called, which allocates a chunk of memory by using pg_malloc and returns it. However, the return chunk is directly passed to snprintf as its 3rd parameter. As a result, there is a memory leak.
1053 static void
1054 setup_config(void)
1055 {
...
1094 snprintf(repltok, sizeof(repltok), "min_wal_size = %s",
1095 pretty_wal_size(DEFAULT_MIN_WAL_SEGS));
...
1347 }
1036 static char *
1037 pretty_wal_size(int segment_count)
1038 {
1039 int sz = wal_segment_size_mb * segment_count;
1040 char *result = pg_malloc(14);
1041
1042 if ((sz % 1024) == 0)
1043 snprintf(result, 14, "%dGB", sz / 1024);
1044 else
1045 snprintf(result, 14, "%dMB", sz);
1046
1047 return result;
1048 }
We believe we can fix this problem by adding a variable to receive the return of pretty_wal_size() and employing pg_free() to free the leaked memory.
I'm looking forward to your confirmation.
Best,
Wentao
