On Wed, Mar 23, 2022 at 1:16 AM Michael Paquier <mich...@paquier.xyz> wrote: > As far as I can see, this is > also possible in bt_page_items_bytea(), gist_page_opaque_info(), > gin_metapage_info() and gin_page_opaque_info(). All those code paths > should be protected with some checks on PageGetSpecialSize(), I > guess, before attempting to read the special area of the page. Hash > indexes are protected by checking the expected size of the special > area, and one code path of btree relies on the opened relation to be a > btree index.
amcheck's palloc_btree_page() function validates that an 8KiB page is in fact an nbtree page, in a maximally paranoid way. Might be an example worth following here. -- Peter Geoghegan
