postgres.git / summary / log / commit / refs

commit    b0f7dd915bca6243f3daf52a81b8d0682a38ee3b
Author:   Alvaro Herrera <alvherre@alvh.no-ip.org>
Date:     Wed Nov 08 17:44:54 2023 +0000

    Check stack depth in new recursive functions
    
    Commit b0e96f311985 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


 src/backend/commands/tablecmds.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 416a98e7cef..e456ccd767e 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -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);


[parent: 76db9cb6368e]