postgres.git / summary / log / commit / refs

commit    d41fda6aa3c1016ef5aedb4bf393ead81f6e3a8f
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 f51248b70d0..c848d09d14b 100644
--- a/src/backend/utils/cache/typcache.c
+++ b/src/backend/utils/cache/typcache.c
@@ -2707,7 +2707,7 @@ 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: bb18bc224923]