You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

Tom Lane 049e1e2edb Fix mishandling of resjunk columns in ON CONFLICT ... UPDATE tlists. ... It's unusual to have any resjunk columns in an ON CONFLICT ... UPDATE list, but it can happen when MULTIEXPR_SUBLINK SubPlans are present. If it happens, the ON CONFLICT UPDATE code path would end up storing tuples that include the values of the extra resjunk columns. That's fairly harmless in the short run, but if new columns are added to the table then the values would become accessible, possibly leading to malfunctions if they don't match the datatypes of the new columns. This had escaped notice through a confluence of missing sanity checks, including * There's no cross-check that a tuple presented to heap_insert or heap_update matches the table rowtype. While it's difficult to check that fully at reasonable cost, we can easily add assertions that there aren't too many columns. * The output-column-assignment cases in execExprInterp.c lacked any sanity checks on the output column numbers, which seems like an oversight considering there are plenty of assertion checks on input column numbers. Add assertions there too. * We failed to apply nodeModifyTable's ExecCheckPlanOutput() to the ON CONFLICT UPDATE tlist. That wouldn't have caught this specific error, since that function is chartered to ignore resjunk columns; but it sure seems like a bad omission now that we've seen this bug. In HEAD, the right way to fix this is to make the processing of ON CONFLICT UPDATE tlists work the same as regular UPDATE tlists now do, that is don't add "SET x = x" entries, and use ExecBuildUpdateProjection to evaluate the tlist and combine it with old values of the not-set columns. This adds a little complication to ExecBuildUpdateProjection, but allows removal of a comparable amount of now-dead code from the planner. In the back branches, the most expedient solution seems to be to (a) use an output slot for the ON CONFLICT UPDATE projection that actually matches the target table, and then (b) invent a variant of ExecBuildProjectionInfo that can be told to not store values resulting from resjunk columns, so it doesn't try to store into nonexistent columns of the output slot. (We can't simply ignore the resjunk columns altogether; they have to be evaluated for MULTIEXPR_SUBLINK to work.) This works back to v10. In 9.6, projections work much differently and we can't cheaply give them such an option. The 9.6 version of this patch works by inserting a JunkFilter when it's necessary to get rid of resjunk columns. In addition, v11 and up have the reverse problem when trying to perform ON CONFLICT UPDATE on a partitioned table. Through a further oversight, adjust_partition_tlist() discarded resjunk columns when re-ordering the ON CONFLICT UPDATE tlist to match a partition. This accidentally prevented the storing-bogus-tuples problem, but at the cost that MULTIEXPR_SUBLINK cases didn't work, typically crashing if more than one row has to be updated. Fix by preserving resjunk columns in that routine. (I failed to resist the temptation to add more assertions there too, and to do some minor code beautification.) Per report from Andres Freund. Back-patch to all supported branches. Security: CVE-2021-32028		4 years ago
..
backend	Fix mishandling of resjunk columns in ON CONFLICT ... UPDATE tlists.	4 years ago
bin	Translation updates	4 years ago
common	Factor out system call names from error messages	4 years ago
fe_utils	psql: Fix line continuation prompts for unbalanced parentheses	4 years ago
include	Fix mishandling of resjunk columns in ON CONFLICT ... UPDATE tlists.	4 years ago
interfaces	Translation updates	4 years ago
makefiles	Remove libpq.rc, use win32ver.rc for libpq	6 years ago
pl	Translation updates	4 years ago
port	Fix typos and grammar in comments and docs	4 years ago
template	Further tweaking of PG_SYSROOT heuristics for macOS.	5 years ago
test	Fix mishandling of resjunk columns in ON CONFLICT ... UPDATE tlists.	4 years ago
timezone	Update time zone data files to tzdata release 2021a.	4 years ago
tools	Revert recovery prefetching feature.	4 years ago
tutorial	doc: Prefer explicit JOIN syntax over old implicit syntax in tutorial	4 years ago
.gitignore	…
DEVELOPERS	…
Makefile	Remove the option to build thread_test.c outside configure.	5 years ago
Makefile.global.in	Update Unicode data to CLDR 39	4 years ago
Makefile.shlib	Add PostgreSQL home page to --help output	5 years ago
nls-global.mk	Add errhint_plural() function and make use of it	4 years ago