Fix memory leaks in GIN index vacuum.

Per bug #12850 by Walter Nordmann. Backpatch to 9.4 where the leak was
introduced.

diff --git a/src/backend/access/gin/ginvacuum.c b/src/backend/access/gin/ginvacuum.c
index 9e76df36129f0497637bf295ce8e2428532e1a22..eba572b0d8afaff71815b3d9bebdc8ce07f69086 100644 (file)
--- a/src/backend/access/gin/ginvacuum.c
+++ b/src/backend/access/gin/ginvacuum.c
@@ -432,27 +432,32 @@ ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint3
        else if (GinGetNPosting(itup) > 0)
        {
            int         nitems;
-           ItemPointer uncompressed;
+           ItemPointer items_orig;
+           bool        free_items_orig;
+           ItemPointer items;
 
-           /*
-            * Vacuum posting list with proper function for compressed and
-            * uncompressed format.
-            */
+           /* Get list of item pointers from the tuple. */
            if (GinItupIsCompressed(itup))
-               uncompressed = ginPostingListDecode((GinPostingList *) GinGetPosting(itup), &nitems);
+           {
+               items_orig = ginPostingListDecode((GinPostingList *) GinGetPosting(itup), &nitems);
+               free_items_orig = true;
+           }
            else
            {
-               uncompressed = (ItemPointer) GinGetPosting(itup);
+               items_orig = (ItemPointer) GinGetPosting(itup);
                nitems = GinGetNPosting(itup);
+               free_items_orig = false;
            }
 
-           uncompressed = ginVacuumItemPointers(gvs, uncompressed, nitems,
-                                                &nitems);
-           if (uncompressed)
+           /* Remove any items from the list that need to be vacuumed. */
+           items = ginVacuumItemPointers(gvs, items_orig, nitems, &nitems);
+
+           if (free_items_orig)
+               pfree(items_orig);
+
+           /* If any item pointers were removed, recreate the tuple. */
+           if (items)
            {
-               /*
-                * Some ItemPointers were deleted, recreate tuple.
-                */
                OffsetNumber attnum;
                Datum       key;
                GinNullCategory category;
@@ -461,7 +466,7 @@ ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint3
 
                if (nitems > 0)
                {
-                   plist = ginCompressPostingList(uncompressed, nitems, GinMaxItemSize, NULL);
+                   plist = ginCompressPostingList(items, nitems, GinMaxItemSize, NULL);
                    plistsize = SizeOfGinPostingList(plist);
                }
                else
@@ -500,6 +505,7 @@ ginVacuumEntryPage(GinVacuumState *gvs, Buffer buffer, BlockNumber *roots, uint3
                         RelationGetRelationName(gvs->index));
 
                pfree(itup);
+               pfree(items);
            }
        }
    }