[postgis-tickets] [PostGIS] #4621: oss-fuzz: stack overflow in lwcollection_from_wkb_state

[PostGIS]

#4621: oss-fuzz: stack overflow in lwcollection_from_wkb_state
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  Reporter:  komzpa   |      Owner:  pramsey
      Type:  defect   |     Status:  new
  Priority:  medium   |  Milestone:  PostGIS 3.1.0
 Component:  postgis  |    Version:  master
Resolution:           |   Keywords:
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Comment (by Algunenano):

 A simpler repro:
 {{{
         /* OSS-FUZZ: https://trac.osgeo.org/postgis/ticket/4621 */
         uint32_t big_size = 20000000;
         uint8_t *wkb5 = lwalloc(big_size);
         memset(wkb5, 0x01, big_size);
         g = lwgeom_from_wkb(wkb5, big_size, LW_PARSER_CHECK_NONE);
         lwgeom_free(g);
         lwfree(wkb5);
 }}}

 I think we should put a limit to the recursive calls that depend on user
 input, but I'm not sure what that would be. I'd say that if you have 1024
 chained collection you are just trying to break things so we could discard
 it.

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Ticket URL: <https://trac.osgeo.org/postgis/ticket/4621#comment:2>
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