diff --git a/src/backend/utils/adt/array_userfuncs.c b/src/backend/utils/adt/array_userfuncs.c
index 67222b19941..62ff6f49f33 100644
--- a/src/backend/utils/adt/array_userfuncs.c
+++ b/src/backend/utils/adt/array_userfuncs.c
@@ -376,7 +376,7 @@ array_cat(PG_FUNCTION_ARGS)
 		dataoffset = 0;			/* marker for no null bitmap */
 		nbytes = ndatabytes + ARR_OVERHEAD_NONULLS(ndims);
 	}
-	result = (ArrayType *) palloc(nbytes);
+	result = (ArrayType *) palloc0(nbytes);
 	SET_VARSIZE(result, nbytes);
 	result->ndim = ndims;
 	result->dataoffset = dataoffset;
diff --git a/src/backend/utils/adt/arrayfuncs.c b/src/backend/utils/adt/arrayfuncs.c
index b36af2c0f09..87e611573ab 100644
--- a/src/backend/utils/adt/arrayfuncs.c
+++ b/src/backend/utils/adt/arrayfuncs.c
@@ -1273,7 +1273,7 @@ array_recv(PG_FUNCTION_ARGS)
 		dataoffset = 0;			/* marker for no null bitmap */
 		nbytes += ARR_OVERHEAD_NONULLS(ndim);
 	}
-	retval = (ArrayType *) palloc(nbytes);
+	retval = (ArrayType *) palloc0(nbytes);
 	SET_VARSIZE(retval, nbytes);
 	retval->ndim = ndim;
 	retval->dataoffset = dataoffset;
@@ -1911,7 +1911,7 @@ array_get_slice(ArrayType *array,
 		bytes += ARR_OVERHEAD_NONULLS(ndim);
 	}
 
-	newarray = (ArrayType *) palloc(bytes);
+	newarray = (ArrayType *) palloc0(bytes);
 	SET_VARSIZE(newarray, bytes);
 	newarray->ndim = ndim;
 	newarray->dataoffset = dataoffset;
@@ -2164,7 +2164,7 @@ array_set(ArrayType *array,
 	/*
 	 * OK, create the new array and fill in header/dimensions
 	 */
-	newarray = (ArrayType *) palloc(newsize);
+	newarray = (ArrayType *) palloc0(newsize);
 	SET_VARSIZE(newarray, newsize);
 	newarray->ndim = ndim;
 	newarray->dataoffset = newhasnulls ? overheadlen : 0;
@@ -2494,7 +2494,7 @@ array_set_slice(ArrayType *array,
 
 	newsize = overheadlen + olddatasize - olditemsize + newitemsize;
 
-	newarray = (ArrayType *) palloc(newsize);
+	newarray = (ArrayType *) palloc0(newsize);
 	SET_VARSIZE(newarray, newsize);
 	newarray->ndim = ndim;
 	newarray->dataoffset = newhasnulls ? overheadlen : 0;
@@ -2753,7 +2753,7 @@ array_map(FunctionCallInfo fcinfo, Oid inpType, Oid retType,
 		dataoffset = 0;			/* marker for no null bitmap */
 		nbytes += ARR_OVERHEAD_NONULLS(ndim);
 	}
-	result = (ArrayType *) palloc(nbytes);
+	result = (ArrayType *) palloc0(nbytes);
 	SET_VARSIZE(result, nbytes);
 	result->ndim = ndim;
 	result->dataoffset = dataoffset;
@@ -2889,7 +2889,7 @@ construct_md_array(Datum *elems,
 		dataoffset = 0;			/* marker for no null bitmap */
 		nbytes += ARR_OVERHEAD_NONULLS(ndims);
 	}
-	result = (ArrayType *) palloc(nbytes);
+	result = (ArrayType *) palloc0(nbytes);
 	SET_VARSIZE(result, nbytes);
 	result->ndim = ndims;
 	result->dataoffset = dataoffset;
@@ -2913,7 +2913,7 @@ construct_empty_array(Oid elmtype)
 {
 	ArrayType  *result;
 
-	result = (ArrayType *) palloc(sizeof(ArrayType));
+	result = (ArrayType *) palloc0(sizeof(ArrayType));
 	SET_VARSIZE(result, sizeof(ArrayType));
 	result->ndim = 0;
 	result->dataoffset = 0;
diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index 10fc79f1162..c1276b78c12 100644
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -1476,6 +1476,8 @@ path_recv(PG_FUNCTION_ARGS)
 	SET_VARSIZE(path, size);
 	path->npts = npts;
 	path->closed = (closed ? 1 : 0);
+	/* prevent instability in unused pad bytes */
+	path->dummy = 0;
 
 	for (i = 0; i < npts; i++)
 	{
@@ -4090,6 +4092,8 @@ path_add(PG_FUNCTION_ARGS)
 	SET_VARSIZE(result, size);
 	result->npts = (p1->npts + p2->npts);
 	result->closed = p1->closed;
+	/* prevent instability in unused pad bytes */
+	result->dummy = 0;
 
 	for (i = 0; i < p1->npts; i++)
 	{
@@ -4323,6 +4327,8 @@ poly_path(PG_FUNCTION_ARGS)
 	SET_VARSIZE(path, size);
 	path->npts = poly->npts;
 	path->closed = TRUE;
+	/* prevent instability in unused pad bytes */
+	path->dummy = 0;
 
 	for (i = 0; i < poly->npts; i++)
 	{