Fix btree_gist's NotEqual strategy on internal index pages. gbt_var_consistent() handled the <> (BtreeGistNotEqual) strategy without distinguishing leaf from internal pages, unlike every other strategy. In particular, it tried to apply the datatype-specific f_eq method, which is completely wrong since internal keys might not have the same representation as leaf keys. This led to OOB reads and potentially crashes, and most likely to wrong query results as well.
On leaf pages we can apply the inverse of what the Equal strategy does. On internal pages, use a correct implementation of what the previous code intended: we can descend if the query value equals both bounds, *so long as the bounds aren't truncated*. With truncated bounds we don't quite know the range of what's below, so we must always descend. Adjust the code in gbt_num_consistent() to look similar, too. This fixes a performance buglet in that there's no need to do two comparisons on a leaf entry, but the main point is just to keep code consistency. Reported-by: 王跃林 <[email protected]> Author: Ayush Tiwari <[email protected]> Reviewed-by: Tom Lane <[email protected]> Discussion: https://postgr.es/m/AH*avqcykhqgvvpwi1giu4oy.8.1781609375063.hmail.3020001...@tju.edu.cn Backpatch-through: 14 Branch ------ REL_14_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/286f9a3cec4b9c4b1d1c49d0b35b6ef074ed2629 Modified Files -------------- contrib/btree_gist/btree_utils_num.c | 15 +++++++++++++-- contrib/btree_gist/btree_utils_var.c | 23 +++++++++++++++++++++-- 2 files changed, 34 insertions(+), 4 deletions(-)
