Sir Mordred The Traitor <mordred@s-mail.com> writes:

> Upon invoking a polygon(integer, circle) function a
> src/backend/utils/adt/geo_ops.c:circle_poly() function will gets
> called, which suffers from a buffer overflow.
>
> 2) A src/backend/adt/utils/geo_ops.c:path_encode() fails to detect a
> buffer overrun condition. It is called in multiple places, the most
> interesting are path_out() and poly_out() functions.

> 5) A src/backend/utils/adt/geo_ops.c:path_add() also fails to detect
> a simple buffer overrun.

I've attached a patch which should fix these problems.

Neil Conway

diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index 9fac9a8e23576cfe645dcb7d17bbe7e64ab74181..ec970bbcbafd8ea6580b497bf4f923bfd2a82bb7 100644 (file)
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.63 2002/07/16 03:30:27 momjian Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_ops.c,v 1.64 2002/08/29 23:05:44 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -269,11 +269,17 @@ path_decode(int opentype, int npts, char *str, int *isopen, char **ss, Point *p)
 static char *
 path_encode(bool closed, int npts, Point *pt)
 {
-       char       *result = palloc(npts * (P_MAXLEN + 3) + 2);
-
+       int                     size = npts * (P_MAXLEN + 3) + 2;
+       char       *result;
        char       *cp;
        int                     i;
 
+       /* Check for integer overflow */
+       if ((size - 2) / npts != (P_MAXLEN + 3))
+               elog(ERROR, "Too many points requested");
+
+       result = palloc(size);
+
        cp = result;
        switch (closed)
        {
@@ -1230,7 +1236,7 @@ path_in(PG_FUNCTION_ARGS)
                depth++;
        }
 
-       size = offsetof(PATH, p[0]) +sizeof(path->p[0]) * npts;
+       size = offsetof(PATH, p[0]) + sizeof(path->p[0]) * npts;
        path = (PATH *) palloc(size);
 
        path->size = size;
@@ -3596,13 +3602,21 @@ path_add(PG_FUNCTION_ARGS)
        PATH       *p1 = PG_GETARG_PATH_P(0);
        PATH       *p2 = PG_GETARG_PATH_P(1);
        PATH       *result;
-       int                     size;
+       int                     size,
+                               base_size;
        int                     i;
 
        if (p1->closed || p2->closed)
                PG_RETURN_NULL();
 
-       size = offsetof(PATH, p[0]) +sizeof(p1->p[0]) * (p1->npts + p2->npts);
+       base_size = sizeof(p1->p[0]) * (p1->npts + p2->npts);
+       size = offsetof(PATH, p[0]) + base_size;
+
+       /* Check for integer overflow */
+       if (base_size / sizeof(p1->p[0]) != (p1->npts + p2->npts) ||
+               size <= base_size)
+               elog(ERROR, "too many points requested.");
+
        result = (PATH *) palloc(size);
 
        result->size = size;
@@ -4413,17 +4427,24 @@ circle_poly(PG_FUNCTION_ARGS)
        int32           npts = PG_GETARG_INT32(0);
        CIRCLE     *circle = PG_GETARG_CIRCLE_P(1);
        POLYGON    *poly;
-       int                     size;
+       int                     base_size,
+                               size;
        int                     i;
        double          angle;
 
        if (FPzero(circle->radius) || (npts < 2))
                elog(ERROR, "Unable to convert circle to polygon");
 
-       size = offsetof(POLYGON, p[0]) +(sizeof(poly->p[0]) * npts);
+       base_size = sizeof(poly->p[0]) * npts;
+       size = offsetof(POLYGON, p[0]) + base_size;
+
+       /* Check for integer overflow */
+       if (base_size / npts != sizeof(poly->p[0]) || size <= base_size)
+               elog(ERROR, "too many points requested");
+
        poly = (POLYGON *) palloc(size);
 
-       MemSet((char *) poly, 0, size);         /* zero any holes */
+       MemSet(poly, 0, size);          /* zero any holes */
        poly->size = size;
        poly->npts = npts;