[postgis-tickets] [PostGIS] #5173: st_asflatgeobuf detoast crash

[PostGIS]

#5173: st_asflatgeobuf detoast crash
---------------------+---------------------------
 Reporter:  robe     |      Owner:  pramsey
     Type:  defect   |     Status:  new
 Priority:  blocker  |  Milestone:  PostGIS 3.2.2
Component:  postgis  |    Version:  3.2.x
 Keywords:           |
---------------------+---------------------------
 Noted on postgis dev mailing list:
 https://lists.osgeo.org/pipermail/postgis-devel/2022-June/029687.html

 and patch at

 https://lists.osgeo.org/pipermail/postgis-devel/2022-June/029689.html


 {{{
 Hi,

 On Sat, Jun 18, 2022 at 06:52:10AM -0500, Justin Pryzby wrote:
 > An instance running pg15beta1 crashed while running one of sqlsmith's
 appalling
 > queries.  I reproduced with this, simplified query:
 >
 >       select st_asflatgeobuf(row(1), false, '')
 >       over () from information_schema.table_privileges
 >
 > Program terminated with signal 11, Segmentation fault.
 > #0  pg_detoast_datum_copy (datum=0x514) at fmgr.c:1719

 All versions of st_asflatgeobuf have the same problem, so you can reduce
 the
 reproducer to:

 select st_asflatgeobuf(row(1)) from pg_class;

 AFAICT, inspect_table() doesn't check that a geometry column was indeed
 found,
 leading to the problem.

 Some like that fixes the crash for me:

 diff --git a/postgis/flatgeobuf.c b/postgis/flatgeobuf.c
 index 1b502e546..545442f31 100644
 --- a/postgis/flatgeobuf.c
 +++ b/postgis/flatgeobuf.c
 @@ -110,6 +110,9 @@ static void inspect_table(struct flatgeobuf_agg_ctx
 *ctx)
         columns_size++;
     }

 +   if (!geom_found)
 +       elog(ERROR, "no geom column found");
 +
     if (columns_size > 0) {
         ctx->ctx->columns = columns;
         ctx->ctx->columns_size = columns_size;
 }}}
-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/5173>
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