Check stack depth in new recursive functions

Commit b0e96f3119 introduced a bunch of recursive functions, but
failed to make them check for stack depth.  This can cause the backend
to crash when operating on inheritance hierarchies several thousands
deep.  Protect the code by adding the missing stack depth checks.

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://postgr.es/m/b2ac2392-9727-5f76-e890-721ac80c1615@gmail.com
This commit is contained in:
Alvaro Herrera 2023-11-08 18:44:54 +01:00
parent 76db9cb636
commit b0f7dd915b
No known key found for this signature in database
GPG Key ID: 1C20ACB9D5C564AE
1 changed files with 12 additions and 0 deletions

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@ -7630,6 +7630,9 @@ set_attnotnull(List **wqueue, Relation rel, AttrNumber attnum, bool recurse,
Form_pg_attribute attForm;
bool retval = false;
/* Guard against stack overflow due to overly deep inheritance tree. */
check_stack_depth();
tuple = SearchSysCacheCopyAttNum(RelationGetRelid(rel), attnum);
if (!HeapTupleIsValid(tuple))
elog(ERROR, "cache lookup failed for attribute %d of relation %u",
@ -7716,6 +7719,9 @@ ATExecSetNotNull(List **wqueue, Relation rel, char *conName, char *colName,
bool is_no_inherit = false;
List *ready = NIL;
/* Guard against stack overflow due to overly deep inheritance tree. */
check_stack_depth();
/*
* In cases of multiple inheritance, we might visit the same child more
* than once. In the topmost call, set up a list that we fill with all
@ -9359,6 +9365,9 @@ ATAddCheckNNConstraint(List **wqueue, AlteredTableInfo *tab, Relation rel,
ListCell *child;
ObjectAddress address = InvalidObjectAddress;
/* Guard against stack overflow due to overly deep inheritance tree. */
check_stack_depth();
/* At top level, permission check was done in ATPrepCmd, else do it */
if (recursing)
ATSimplePermissions(AT_AddConstraint, rel, ATT_TABLE | ATT_FOREIGN_TABLE);
@ -12428,6 +12437,9 @@ dropconstraint_internal(Relation rel, HeapTuple constraintTup, DropBehavior beha
return InvalidObjectAddress;
*readyRels = lappend_oid(*readyRels, RelationGetRelid(rel));
/* Guard against stack overflow due to overly deep inheritance tree. */
check_stack_depth();
/* At top level, permission check was done in ATPrepCmd, else do it */
if (recursing)
ATSimplePermissions(AT_DropConstraint, rel, ATT_TABLE | ATT_FOREIGN_TABLE);