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path: root/contrib/pageinspect/gistfuncs.c
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2022-03-27pageinspect: Add more sanity checks to prevent out-of-bound readsMichael Paquier
A couple of code paths use the special area on the page passed by the function caller, expecting to find some data in it. However, feeding an incorrect page can lead to out-of-bound reads when trying to access the page special area (like a heap page that has no special area, leading PageGetSpecialPointer() to grab a pointer outside the allocated page). The functions used for hash and btree indexes have some protection already against that, while some other functions using a relation OID as argument would make sure that the access method involved is correct, but functions taking in input a raw page without knowing the relation the page is attached to would run into problems. This commit improves the set of checks used in the code paths of BRIN, btree (including one check if a leaf page is found with a non-zero level), GIN and GiST to verify that the page given in input has a special area size that fits with each access method, which is done though PageGetSpecialSize(), becore calling PageGetSpecialPointer(). The scope of the checks done is limited to work with pages that one would pass after getting a block with get_raw_page(), as it is possible to craft byteas that could bypass existing code paths. Having too many checks would also impact the usability of pageinspect, as the existing code is very useful to look at the content details in a corrupted page, so the focus is really to avoid out-of-bound reads as this is never a good thing even with functions whose execution is limited to superusers. The safest approach could be to rework the functions so as these fetch a block using a relation OID and a block number, but there are also cases where using a raw page is useful. Tests are added to cover all the code paths that needed such checks, and an error message for hash indexes is reworded to fit better with what this commit adds. Reported-By: Alexander Lakhin Author: Julien Rouhaud, Michael Paquier Discussion: https://postgr.es/m/16527-ef7606186f0610a1@postgresql.org Discussion: https://postgr.es/m/561e187b-3549-c8d5-03f5-525c14e65bd0@postgrespro.ru Backpatch-through: 10
2022-03-16pageinspect: Fix handling of page sizes and AM typesMichael Paquier
This commit fixes a set of issues related to the use of the SQL functions in this module when the caller is able to pass down raw page data as input argument: - The page size check was fuzzy in a couple of places, sometimes looking after only a sub-range, but what we are looking for is an exact match on BLCKSZ. After considering a few options here, I have settled down to do a generalization of get_page_from_raw(). Most of the SQL functions already used that, and this is not strictly required if not accessing an 8-byte-wide value from a raw page, but this feels safer in the long run for alignment-picky environment, particularly if a code path begins to access such values. This also reduces the number of strings that need to be translated. - The BRIN function brin_page_items() uses a Relation but it did not check the access method of the opened index, potentially leading to crashes. All the other functions in need of a Relation already did that. - Some code paths could fail on elog(), but we should to use ereport() for failures that can be triggered by the user. Tests are added to stress all the cases that are fixed as of this commit, with some junk raw pages (\set VERBOSITY ensures that this works across all page sizes) and unexpected index types when functions open relations. Author: Michael Paquier, Justin Prysby Discussion: https://postgr.es/m/20220218030020.GA1137@telsasoft.com Backpatch-through: 10
2022-03-08Simplify SRFs using materialize mode in contrib/ modulesMichael Paquier
9e98583 introduced a helper to centralize building their needed state (tuplestore, tuple descriptors, etc.), checking for any errors. This commit updates all places of contrib/ that can be switched to use SetSingleFuncCall() as a drop-in replacement, resulting in the removal of a lot of boilerplate code in all the modules updated by this commit. Per analysis, some places remain as they are: - pg_logdir_ls() in adminpack/ uses historically TYPEFUNC_RECORD as return type, and I suspect that changing it may cause issues at run-time with some of its past versions, down to 1.0. - dblink/ uses a wrapper function doing exactly the work of SetSingleFuncCall(). Here the switch should be possible, but rather invasive so it does not seem the extra backpatch maintenance cost. - tablefunc/, similarly, uses multiple helper functions with portions of SetSingleFuncCall() spread across the code paths of this module. Author: Melanie Plageman Discussion: https://postgr.es/m/CAAKRu_bvDPJoL9mH6eYwvBpPtTGQwbDzfJbCM-OjkSZDu5yTPg@mail.gmail.com
2022-01-07Update copyright for 2022Bruce Momjian
Backpatch-through: 10
2021-06-04Adjust locations which have an incorrect copyright yearDavid Rowley
A few patches committed after ca3b37487 mistakenly forgot to make the copyright year 2021. Fix these. Discussion: https://postgr.es/m/CAApHDvqyLmd9P2oBQYJ=DbrV8QwyPRdmXtCTFYPE08h+ip0UJw@mail.gmail.com
2021-02-14Add "LP_DEAD item?" column to GiST pageinspect functionsPeter Geoghegan
This brings gist_page_items() and gist_page_items_bytea() in line with nbtree's bt_page_items() function. Minor follow-up to commit 756ab291, which added the GiST functions. Author: Andrey Borodin <x4mmm@yandex-team.ru> Discussion: https://postgr.es/m/E0794687-7315-4C29-A9C7-EC54D448596D@yandex-team.ru
2021-02-14Avoid misinterpreting GiST pages in pageinspect.Peter Geoghegan
GistPageSetDeleted() sets pd_lower when deleting a page, and sets the page contents to a GISTDeletedPageContents. Avoid treating deleted GiST pages as regular slotted pages within pageinspect. Oversight in commit 756ab291. Author: Andrey Borodin <x4mmm@yandex-team.ru>
2021-01-18Check for BuildIndexValueDescription returning NULL in gist_page_itemsHeikki Linnakangas
Per Coverity. BuildIndexValueDescription() cannot actually return NULL in this instance, because it only returns NULL if the user doesn't have the required privileges, and this function can only be used by superuser. But better safe than sorry.
2021-01-18pageinspect: Fix relcache leak in gist_page_items().Heikki Linnakangas
The gist_page_items() function opened the index relation on first call and closed it on the last call. But there's no guarantee that the function is run to completion, leading to a relcache leak and warning at the end of the transaction. To fix, refactor the function to return all the rows in one call, as a tuplestore. Reported-by: Tom Lane Discussion: https://www.postgresql.org/message-id/234863.1610916631%40sss.pgh.pa.us
2021-01-13Add functions to 'pageinspect' to inspect GiST indexes.Heikki Linnakangas
Author: Andrey Borodin and me Discussion: https://www.postgresql.org/message-id/3E4F9093-A1B5-4DF8-A292-0B48692E3954%40yandex-team.ru