postgres.git / summary / log / commit / refs

commit    82248f227b6d304e2da13655d8458a98682d2dac
Author:   Thomas Munro <tmunro@postgresql.org>
Date:     Sat May 29 02:48:15 2021 +0000
First released in: 14.0, 11.13, 12.8, 13.4

    Fix race condition when sharing tuple descriptors.
    
    Parallel query processes that called BlessTupleDesc() for identical
    tuple descriptors at the same moment could crash.  There was code to
    handle that rare case, but it dereferenced a bogus DSA pointer.  Repair.
    
    Back-patch to 11, where commit cc5f8136 added support for sharing tuple
    descriptors in parallel queries.
    
    Reported-by: Eric Thinnes <e.thinnes@gmx.de>
    Discussion: https://postgr.es/m/99aaa2eb-e194-bf07-c29a-1a76b4f2bcf9%40gmx.de


 src/backend/utils/cache/typcache.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/backend/utils/cache/typcache.c b/src/backend/utils/cache/typcache.c
index 11920db0d99..07a08430d66 100644
--- a/src/backend/utils/cache/typcache.c
+++ b/src/backend/utils/cache/typcache.c
@@ -2617,7 +2617,7 @@ find_or_make_matching_shared_tupledesc(TupleDesc tupdesc)
 		Assert(record_table_entry->key.shared);
 		result = (TupleDesc)
 			dsa_get_address(CurrentSession->area,
-							record_table_entry->key.shared);
+							record_table_entry->key.u.shared_tupdesc);
 		Assert(result->tdrefcount == -1);
 
 		return result;


[parent: 40a05cf245b8]