[postgis-tickets] [PostGIS] #4190: Undefined behaviour in nd_box_overlap (ANALYZE)

[PostGIS]

#4190: Undefined behaviour in nd_box_overlap (ANALYZE)
------------------------+---------------------------
 Reporter:  Algunenano  |      Owner:  Algunenano
     Type:  defect      |     Status:  assigned
 Priority:  medium      |  Milestone:  PostGIS 2.5.1
Component:  postgis     |    Version:  2.5.x
 Keywords:              |
------------------------+---------------------------
 There is a division by zero in the code. Detected running
 regress_selectivity under gcc `-fsanitize=undefined -fsanitize-undefined-
 trap-on-error`.

 {{{
 Core was generated by `postgres: raul postgis_reg [local] ANALYZE '.
 Program terminated with signal SIGILL, Illegal instruction.
 #0  0x00007f1aebd4c355 in nd_box_overlap (nd_stats=0x55c488d68590,
 nd_box=0x55c488d60078, nd_ibox=0x7fffc06a86c0) at
 gserialized_estimate.c:689
 689                     nd_ibox->min[d] = floor(size * (nd_box->min[d] -
 smin) / width);
 (gdb) p width
 $1 = 0
 (gdb) bt
 #0  0x00007f1aebd4c355 in nd_box_overlap (nd_stats=0x55c488d68590,
 nd_box=0x55c488d60078, nd_ibox=0x7fffc06a86c0) at
 gserialized_estimate.c:689
 #1  0x00007f1aebd50e72 in compute_gserialized_stats_mode
 (stats=0x55c488d67ff0, fetchfunc=0x55c4875e5200 <std_fetch_func>,
 sample_rows=1, total_rows=1, mode=2)
     at gserialized_estimate.c:1726
 #2  0x00007f1aebd44772 in compute_gserialized_stats (stats=0x55c488d67ff0,
 fetchfunc=0x55c4875e5200 <std_fetch_func>, sample_rows=1, total_rows=1)
     at gserialized_estimate.c:1858
 #3  0x000055c4875e2578 in do_analyze_rel (onerel=<optimized out>,
 options=2, params=<optimized out>, va_cols=0x0, acquirefunc=0x55c4875e11f0
 <acquire_sample_rows>,
     relpages=1, inh=<optimized out>, in_outer_xact=240, elevel=13) at
 analyze.c:579
 #4  0x000055c4875e0ffe in analyze_rel (relid=<optimized out>,
 relation=<optimized out>, options=2, params=<optimized out>, va_cols=0x0,
 in_outer_xact=<optimized out>,
     bstrategy=0x55c488d63f70) at analyze.c:310
 #5  0x000055c4876597c2 in vacuum (options=2, relations=<optimized out>,
 params=0x7fffc06a8d40, bstrategy=<optimized out>, isTopLevel=<optimized
 out>) at vacuum.c:357
 (gdb) p *nd_stats
 $5 = {ndims = 2, size = {1, 1, 0, 0}, extent = {min = {0, 0, 0, 0}, max =
 {0, 0, 0, 0}}, table_features = 1, sample_features = 1, not_null_features
 = 1,
   histogram_features = 0, histogram_cells = 0, cells_covered = 0, value =
 {0}}
 (gdb) p *nd_box
 $6 = {min = {0, 0, 0, 0}, max = {0, 0, 0, 0}}
 (gdb) p *nd_ibox
 $7 = {min = {0, 0, 0, 0}, max = {0, 0, 0, 0}}
 }}}

 Previous releases might also be affected.

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/4190>
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