segfault with select ST_Node(ST_GeomFromText('LINESTRING EMPTY'))

[cactusbone]

Using PostGIS docker image 14-3.2-alpine, which ships with postgis 3.2.1 and geos 3.10,

I have a segfault with select ST_Node(ST_GeomFromText('LINESTRING EMPTY'))

here's the core dump backtrace

#0  0x00007f36bc780cc7 in geos::noding::SegmentNodeList::add(geos::geom::Coordinate const&, unsigned long) () from /usr/lib/libgeos.so.3.10.2
#1  0x00007f36bc780dea in geos::noding::SegmentNodeList::addEndpoints() () from /usr/lib/libgeos.so.3.10.2
#2  0x00007f36bc781539 in geos::noding::SegmentNodeList::addSplitEdges(std::vector<geos::noding::SegmentString*, std::allocator<geos::noding::SegmentString*> >&) () from /usr/lib/libgeos.so.3.10.2
#3  0x00007f36bc77c5c4 in geos::noding::NodedSegmentString::getNodedSubstrings(std::vector<geos::noding::SegmentString*, std::allocator<geos::noding::SegmentString*> > const&, std::vector<geos::noding::SegmentString*, std::allocator<geos::noding::SegmentString*> >*) () from /usr/lib/libgeos.so.3.10.2
#4  0x00007f36bc77c661 in geos::noding::NodedSegmentString::getNodedSubstrings(std::vector<geos::noding::SegmentString*, std::allocator<geos::noding::SegmentString*> > const&) () from /usr/lib/libgeos.so.3.10.2
#5  0x00007f36bc778f1c in geos::noding::IteratedNoder::node(std::vector<geos::noding::SegmentString*, std::allocator<geos::noding::SegmentString*> >*, int&, geos::geom::Coordinate&) () from /usr/lib/libgeos.so.3.10.2
#6  0x00007f36bc77900c in geos::noding::IteratedNoder::computeNodes(std::vector<geos::noding::SegmentString*, std::allocator<geos::noding::SegmentString*> >*) () from /usr/lib/libgeos.so.3.10.2
#7  0x00007f36bc777f27 in geos::noding::GeometryNoder::getNoded() () from /usr/lib/libgeos.so.3.10.2
#8  0x00007f36bc778030 in geos::noding::GeometryNoder::node(geos::geom::Geometry const&) () from /usr/lib/libgeos.so.3.10.2
#9  0x00007f36bcd811d7 in GEOSNode_r () from /usr/lib/libgeos_c.so.1
#10 0x00007f36bcc632d0 in lwgeom_node (lwgeom_in=lwgeom_in@entry=0x7f36bcdfbbd8) at lwgeom_geos_node.c:156
#11 0x00007f36bcb6e9bc in ST_Node (fcinfo=0x7f36bcdb8d38) at lwgeom_geos.c:3331
#12 0x000056163af61227 in ExecInterpExpr ()
#13 0x000056163b024c30 in evaluate_expr ()
#14 0x000056163b024e81 in simplify_function ()
#15 0x000056163b025d40 in eval_const_expressions_mutator ()
#16 0x000056163afcc229 in expression_tree_mutator ()
#17 0x000056163afcc4ae in expression_tree_mutator ()
#18 0x000056163b026d5f in eval_const_expressions ()
#19 0x000056163b00e0b8 in preprocess_expression ()
#20 0x000056163b0149a3 in subquery_planner ()
#21 0x000056163b015383 in standard_planner ()
#22 0x000056163b0cfceb in pg_plan_query ()
#23 0x000056163b0cfdd1 in pg_plan_queries ()
#24 0x000056163b0d00a5 in exec_simple_query ()
#25 0x000056163b0d2035 in PostgresMain ()
#26 0x000056163b053f73 in ServerLoop ()
#27 0x000056163b054de1 in PostmasterMain ()
#28 0x000056163addcbce in main ()

I'm not sure if the bug is in geos OR PostGIS, so I'm opening it in both places :) See ​https://github.com/libgeos/geos/issues/601

to reproduce easily:

• start docker container docker run --rm --name some-postgres -e POSTGRES_PASSWORD=mysecretpassword -d postgis/postgis:14-3.2-alpine (remove -d to not start in background)
• run query using another container docker run -it --rm --link some-postgres postgres psql postgresql://postgres:mysecretpassword@some-postgres -c "select ST_Node(ST_GeomFromText('LINESTRING EMPTY'))"

2022-05-04 12:16:36.761 UTC [1] LOG: server process (PID 63) was terminated by signal 11: Segmentation fault

2022-05-04 12:16:36.761 UTC [1] DETAIL: Failed process was running: select ST_Node(ST_GeomFromText('LINESTRING EMPTY'))

[cactusbone]

This is now fixed in geos :) not sure if there are more work to do here :)

[robe]

@cactusnode,

Thanks for the update. I still seem to be getting a crash though

In both

POSTGIS="3.2.1 3.2.1" [EXTENSION] PGSQL="140" GEOS="3.10.2-CAPI-1.16.0" PROJ="7.2.1" LIBXML="2.9.9" LIBJSON="0.12" LIBPROTOBUF="1.2.1" WAGYU="0.5.0 (Internal)" PostgreSQL 14.1, compiled by Visual C++ build 1914, 64-bit

and

POSTGIS="3.3.0dev 3.2.0-693-g9870fd492" [EXTENSION] PGSQL="140" GEOS="3.11.0dev-CAPI-1.16.0" PROJ="7.2.1" GDAL="GDAL 3.3.3, released 2021/10/25" LIBXML="2.9.9" LIBJSON="0.12" LIBPROTOBUF="1.2.1" WAGYU="0.5.0 (Internal)" RASTER PostgreSQL 14rc1 on x86_64-w64-mingw32, compiled by gcc.exe (x86_64-posix-seh-rev0, Built by MinGW-W64 project) 8.1.0, 64-bit

Though what puzzles me is this test should be one that is tested in gardentests so I got to check why that isn't picking this up.

[robe]

Okay I'm going to close this out. It works after I updated my geos to geos main. The 3.10.2 I have it's still broken, so I guess that's because this fix was released only 10 days ago so will be in 3.10.3.

[robe]

Okay I discovered how this got past the garden tests.

The garden test does this:

SELECT ST_Node(foo1.the_geom)  As result
 FROM ((SELECT ST_GeomFromText('POINT EMPTY',4326) As the_geom
			UNION ALL SELECT ST_GeomFromText('LINESTRING EMPTY',4326) As the_geom
			UNION ALL SELECT ST_GeomFromText('MULTILINESTRING EMPTY',4326) As the_geom ) ) As foo1 LIMIT 10;

Which errors out before it gets to the noding part, with this error:

ERROR:  Noding geometries of dimension != 1 is unsupported

So I guess I need to add some tests that have these as standalone as well.

[robe]

Note committed at [3389bf53/git] to catch these kind of crashers

[cactusbone]

thx for that ! :)