Don't reference out-of-bounds array elements in brin_minmax_multi.c The primary fix here is to fix has_matching_range() so it does not reference ranges->values[-1] when nranges == 0. Similar problems existed in AssertCheckRanges() too. It does not look like any of these problems could lead to a crash as the array in question is at the end of the Ranges struct, and values[-1] is memory that belongs to other fields in the struct. However, let's get rid of these rather unsafe coding practices.
In passing, I (David) adjusted some comments to try to make it more clear what some of the fields are for in the Ranges struct. I had to study the code to find out what nsorted was for as I couldn't tell from the comments. Author: Ranier Vilela Discussion: https://postgr.es/m/CAEudQAqJQzPitufX-jR=yubjafpcdakunwgdbx_mzsc93wu...@mail.gmail.com Backpatch-through: 14, where multi-range brin was added. Branch ------ master Details ------- https://git.postgresql.org/pg/commitdiff/6b89ce1a21f909f616db165dcc6d8d2918fbc185 Modified Files -------------- src/backend/access/brin/brin_minmax_multi.c | 172 ++++++++++++++-------------- 1 file changed, 88 insertions(+), 84 deletions(-)
